[
{
"id": "authors:2w6vy-f0691",
"collection": "authors",
"collection_id": "2w6vy-f0691",
"cite_using_url": "https://authors.library.caltech.edu/records/2w6vy-f0691",
"type": "article",
"title": "Compressed ultrafast photography of plasmas formed from laser breakdown of dense gases reveals that internal processes dominate evolution at early times",
"author": [
{
"family_name": "Wang",
"given_name": "Peng",
"orcid": "0000-0002-6302-8495",
"clpid": "Wang-Peng"
},
{
"family_name": "Mishra",
"given_name": "Yogeshwar Nath",
"orcid": "0000-0003-2063-2200",
"clpid": "Mishra-Yogeshwar-Nath"
},
{
"family_name": "Pree",
"given_name": "Seth",
"orcid": "0000-0003-1917-3166",
"clpid": "Pree-Seth"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Hanstorp",
"given_name": "Dag",
"orcid": "0000-0001-6490-6897"
},
{
"family_name": "Koulakis",
"given_name": "John P.",
"orcid": "0000-0003-0207-1462"
},
{
"family_name": "Krimans",
"given_name": "Daniels",
"orcid": "0009-0005-7582-2986"
},
{
"family_name": "Putterman",
"given_name": "Seth"
}
],
"abstract": "Compressed ultrafast photography (CUP) is applied to laser breakdown in argon and xenon under pressures up to 40 bars to obtain two-dimensional images of the plasma dynamics of single events with a spatial resolution of 250×100 pixels and an equivalent frame rate of 500 GHz. Light emission as a function of position and time is measured through red, green, blue, and broadband filters. The spatially encoded and temporally sheared image normally used in CUP is now enhanced by the introduction of a constraint given by a spatially integrated and temporally sheared unencoded signal. The data yield insights into the temperature, opacity, the plasma formation process, and heat flow within the plasma and to the surrounding ambient gas. Contours of constant emission indicate that plasmas formed from sufficiently dense gas contract rather than expand despite having a temperature of a few eV. Plasmas formed from relatively low pressure gases such as 7-bar argon can radiate with emissivity near unity. Modeling transport and opacity as arising from inverse Bremsstrahlung requires a degree of ionization that strongly exceeds expectations based on Saha's equation even as customarily modified to include density and screening. According to this model, both electrons and ions are strongly coupled with a plasma coefficient \u22731. During the first few nanoseconds after formation, Stefan-Boltzmann radiation and thermal conduction to ambient gas are too weak to explain the observed cooling rates, suggesting that transport within the plasma dominates its evolution. Yet, thermal conduction within the plasma itself is also small as indicated by the persistence of thermal inhomogeneities for far longer timescales. The fact that plasma is isolated from the surroundings makes it an excellent system for the study of the equation of state and hydrodynamics of such dense plasmas via the systems and techniques described.
",
"doi": "10.1103/3vw9-h2g5",
"issn": "2470-0045",
"publisher": "American Physical Society",
"publication": "Physical Review E",
"publication_date": "2026-01-30",
"series_number": "1",
"volume": "113",
"issue": "1",
"pages": "015209"
},
{
"id": "authors:y4b79-gg191",
"collection": "authors",
"collection_id": "y4b79-gg191",
"cite_using_url": "https://authors.library.caltech.edu/records/y4b79-gg191",
"type": "article",
"title": "Panoramic photoacoustic computed tomography with learning-based classification enhances breast lesion characterization",
"author": [
{
"family_name": "Tong",
"given_name": "Xin"
},
{
"family_name": "Liu",
"given_name": "Cindy Z.",
"orcid": "0000-0002-1075-1436",
"clpid": "Liu-Cindy-Z"
},
{
"family_name": "Luo",
"given_name": "Yilin",
"orcid": "0000-0002-4611-3049",
"clpid": "Luo-Yilin"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436"
},
{
"family_name": "Dzubnar",
"given_name": "Jessica",
"orcid": "0000-0002-6735-1687"
},
{
"family_name": "Invernizzi",
"given_name": "Marta"
},
{
"family_name": "Delos Santos",
"given_name": "Stephanie"
},
{
"family_name": "Zhang",
"given_name": "Yide",
"orcid": "0000-0002-9463-3970",
"clpid": "Zhang-Yide"
},
{
"family_name": "Cao",
"given_name": "Rui",
"orcid": "0000-0003-4444-7528",
"clpid": "Cao-Rui"
},
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Zheng",
"given_name": "Junfu",
"clpid": "Zheng-Junfu"
},
{
"family_name": "Torres",
"given_name": "Jaclene"
},
{
"family_name": "Kasabyan",
"given_name": "Armine"
},
{
"family_name": "Lai",
"given_name": "Lily L."
},
{
"family_name": "Yee",
"given_name": "Lisa D.",
"orcid": "0000-0001-8243-1055"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Breast cancer diagnosis is crucial due to the high prevalence and mortality rate associated with the disease. However, mammography involves ionizing radiation and has compromised sensitivity in radiographically dense breasts, ultrasonography lacks specificity and has operator-dependent image quality, and magnetic resonance imaging faces high cost and patient exclusion. Photoacoustic computed tomography (PACT) offers a promising solution by combining light and ultrasound for high-resolution imaging that detects tumour-related vasculature changes. Here we introduce a workflow using panoramic PACT for breast lesion characterization, offering detailed visualization of vasculature irrespective of breast density. Analysing PACT features of 78 breasts in 39 patients, we develop learning-based classifiers to distinguish between normal and suspicious tissue, achieving a maximum area under the receiver operating characteristic curve of 0.89, which is comparable with that of conventional imaging standards. We further differentiate malignant and benign lesions using 13 features. Finally, we developed a learning-based model to segment breast lesions. Our study identifies PACT as a non-invasive and sensitive imaging tool for breast lesion evaluation.
",
"doi": "10.1038/s41551-025-01435-3",
"pmcid": "PMC13067902",
"issn": "2157-846X",
"publisher": "Nature Publishing Group",
"publication": "Nature Biomedical Engineering",
"publication_date": "2026-01",
"series_number": "1",
"volume": "10",
"issue": "1",
"pages": "161-177"
},
{
"id": "authors:g7ykw-rnq63",
"collection": "authors",
"collection_id": "g7ykw-rnq63",
"cite_using_url": "https://authors.library.caltech.edu/records/g7ykw-rnq63",
"type": "article",
"title": "Optical focusing into scattering media via iterative time reversal guided by absorption nonlinearity",
"author": [
{
"family_name": "Cui",
"given_name": "Manxiu",
"orcid": "0000-0003-0788-9511",
"clpid": "Cui-Manxiu"
},
{
"family_name": "Kahraman",
"given_name": "S. S\u00fcleyman",
"orcid": "0000-0001-8154-367X",
"clpid": "Kahraman-S-S\u00fcleyman"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Guide star-assisted time-reversal enables deep optical focusing in scattering media such as biological tissue, overcoming the diffusion limit of light. However, in practice, guide stars formed using contrast agents or ultrasonic modulation naturally occupy regions much larger than the optical resolution, thus limiting their effectiveness. We propose and experimentally demonstrate a time-reversal focusing mechanism in scattering media that achieves focusing to a single speckle grain without the need for point-like guide stars. We exploit optical absorption nonlinearity as a light-induced perturbation to create virtual guide stars. The back-scattered fields in response to high- and low-intensity illuminations are subtracted after scaling to synthesize the field from the dominant speckle grains in the medium. We use this time-reversed field as the incident illumination in subsequent iterations. The focusing is achieved despite the extended layer of nonlinear absorber via a positive feedback loop that favors higher-intensity speckle grains, converging to a single virtual guide star at the optical resolution. We also demonstrate that by adding a phase ramp in each iteration, this focus can be gradually steered beyond the memory effect range.
",
"doi": "10.1038/s41467-025-63095-w",
"pmcid": "PMC12370915",
"issn": "2041-1723",
"publisher": "Nature Publishing Group",
"publication": "Nature Communications",
"publication_date": "2025-08-21",
"series_number": "1",
"volume": "16",
"issue": "1",
"pages": "7807"
},
{
"id": "authors:fj43g-j0x37",
"collection": "authors",
"collection_id": "fj43g-j0x37",
"cite_using_url": "https://authors.library.caltech.edu/records/fj43g-j0x37",
"type": "article",
"title": "Single-shot two-dimensional nano-size mapping of fluorescent molecules by ultrafast polarization anisotropy imaging",
"author": [
{
"family_name": "Wang",
"given_name": "Peng"
},
{
"family_name": "Mishra",
"given_name": "Yogeshwar Nath",
"orcid": "0000-0003-2063-2200",
"clpid": "Mishra-Yogeshwar-Nath"
},
{
"family_name": "Bauer",
"given_name": "Florian J.",
"orcid": "0000-0001-8590-1841"
},
{
"family_name": "Gudipati",
"given_name": "Murthy S.",
"orcid": "0000-0001-5992-373X"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "\n
\n
Molecular size plays a crucial role in determining the physical, chemical, and biological properties of substances. However, traditional fluorescence polarization anisotropy methods struggle to capture fast transient processes or provide plane-specific details. To overcome these limitations, we introduce Compressed Ultrafast Planar Polarization Anisotropy Imaging (CUP2AI). This approach combines femtosecond laser-sheet illumination, molecular rotational diffusivity, and compressed sensing to enable real-time, non-invasive, wide-field anisotropy measurements in both liquid and gas phases. CUP2AI captures 2D molecular size mapping in a single acquisition, granting unprecedented insights into dynamic events across various excitation modes (i.e. both one- and two-photon) and environmental conditions. It enables mapping of molecular volume (500 ų–80,000 ų) and hydrodynamic diameter (10 Å–50 Å) based on anisotropy lifetimes. We imaged fluorescein-conjugated dextran in water and polycyclic aromatic hydrocarbons in flames. CUP2AI holds transformative potential for applications ranging from molecular biology and drug design to nanoparticle formation.
\n
\n
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",
"doi": "10.1038/s41467-025-60072-1",
"issn": "2041-1723",
"publisher": "Nature Publishing Group",
"publication": "Nature Communications",
"publication_date": "2025-05-30",
"series_number": "1",
"volume": "16",
"issue": "1",
"pages": "5019"
},
{
"id": "authors:b2vr5-q7618",
"collection": "authors",
"collection_id": "b2vr5-q7618",
"cite_using_url": "https://authors.library.caltech.edu/records/b2vr5-q7618",
"type": "article",
"title": "Photoacoustic Tomography in Cardiovascular Medicine: Innovations in Assessing Hemodynamics and Metabolic Function",
"author": [
{
"family_name": "Luo",
"given_name": "Yilin",
"orcid": "0000-0002-4611-3049",
"clpid": "Luo-Yilin"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Purpose of Review
\nPhotoacoustic tomography (PAT) has emerged as a promising non-ionizing imaging modality that leverages optical absorption contrast to provide anatomical, functional, and metabolic insights. This review highlights recent advancements in PAT for assessing hemodynamics and metabolic function in the diagnosis, treatment, and monitoring of cardiovascular diseases (CVDs).
\nRecent Findings
\nPAT has been applied to evaluate vascular morphology, blood flow, perfusion, and cardiac hemodynamics. It has also been used for metabolic assessments, including oxygenation, lipid accumulation, glucose dynamics, collagen distribution, and inflammatory responses.
\nSummary
\nBy selecting appropriate wavelengths, PAT can target specific molecular contrasts, while multi-wavelength imaging enables simultaneous visualization of multiple biomarkers. These capabilities provide a comprehensive view of CVD progression and treatment. Ongoing technological advancements, clinical trials, and translational efforts are essential for validating PAT’s clinical utility and accelerating its integration into routine cardiovascular care.
",
"doi": "10.1007/s11936-025-01092-4",
"issn": "1092-8464",
"publisher": "Springer Science and Business Media LLC",
"publication": "Current Treatment Options in Cardiovascular Medicine",
"publication_date": "2025-05-23",
"series_number": "1",
"volume": "27",
"issue": "1",
"pages": "35"
},
{
"id": "authors:5dgz8-7ja31",
"collection": "authors",
"collection_id": "5dgz8-7ja31",
"cite_using_url": "https://authors.library.caltech.edu/records/5dgz8-7ja31",
"type": "article",
"title": "Simulation of atom trajectories in the original Stern\u2013Gerlach experiment",
"author": [
{
"family_name": "Mostafaeipour",
"given_name": "Faraz",
"clpid": "Mostafaeipour-Faraz"
},
{
"family_name": "Kahraman",
"given_name": "S S\u00fcleyman",
"orcid": "0000-0001-8154-367X",
"clpid": "Kahraman-S-S\u00fcleyman"
},
{
"family_name": "Titimbo",
"given_name": "Kelvin",
"orcid": "0000-0002-4700-3482",
"clpid": "Titimbo-Kelvin"
},
{
"family_name": "Tan",
"given_name": "Yixuan",
"clpid": "Tan-Yixuan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Following a comprehensive analysis of the historical literature, we model the geometry of the Stern–Gerlach experiment to numerically calculate the magnetic field using the finite-element method. Using this calculated field and Monte Carlo methods, the semiclassical atomic translational dynamics are simulated to produce the well-known quantized end-pattern with matching dimensions. The finite-element method used provides the most accurate description of the Stern–Gerlach magnetic field and end-pattern in the literature, matching the historically reported values and figures.
",
"doi": "10.1088/1402-4896/adbf6c",
"issn": "0031-8949",
"publisher": "IOP Publishing",
"publication": "Physica Scripta",
"publication_date": "2025-04",
"series_number": "4",
"volume": "100",
"issue": "4",
"pages": "045410"
},
{
"id": "authors:b5xwh-vt765",
"collection": "authors",
"collection_id": "b5xwh-vt765",
"cite_using_url": "https://authors.library.caltech.edu/records/b5xwh-vt765",
"type": "article",
"title": "Transcranial photoacoustic tomography de-aberrated using boundary elements",
"author": [
{
"family_name": "Sastry",
"given_name": "Karteekeya",
"orcid": "0000-0001-7659-4878",
"clpid": "Sastry-Karteekeya"
},
{
"family_name": "Aborahama",
"given_name": "Yousuf",
"orcid": "0000-0002-9527-8923",
"clpid": "Aborahama-Yousuf"
},
{
"family_name": "Luo",
"given_name": "Yilin",
"orcid": "0000-0002-4611-3049",
"clpid": "Luo-Yilin"
},
{
"family_name": "Zhang",
"given_name": "Yang",
"orcid": "0000-0002-4533-4325",
"clpid": "Zhang-Yang"
},
{
"family_name": "Cui",
"given_name": "Manxiu",
"orcid": "0000-0003-0788-9511",
"clpid": "Cui-Manxiu"
},
{
"family_name": "Cao",
"given_name": "Rui",
"orcid": "0000-0003-4444-7528",
"clpid": "Cao-Rui"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography holds tremendous potential for neuroimaging due to its functional magnetic resonance imaging (fMRI)-like functional contrast and greater specificity, richer contrast, portability, open platform, faster imaging, magnet-free and quieter operation, and lower cost. However, accounting for the skull-induced acoustic distortion remains a long-standing challenge due to the problem size. This is aggravated in functional imaging, where high accuracy is needed to detect minuscule functional changes. Here, we develop an acoustic solver based on the boundary-element method (BEM) to model the skull and de-aberrate the images. BEM uses boundary meshes and compression for superior computational efficiency compared to volumetric discretization-based methods. We demonstrate BEM's higher accuracy and favorable scalability relative to the widely used pseudo-spectral time-domain method (PSTD). In imaging through an ex-vivo adult human skull, BEM outperforms PSTD in several metrics. Our work establishes BEM as a valuable and naturally suited technique in photoacoustic tomography and lays the foundation for BEM-based de-aberration methods.",
"doi": "10.1109/tmi.2025.3526000",
"issn": "0278-0062",
"publisher": "IEEE",
"publication": "IEEE Transactions on Medical Imaging",
"publication_date": "2025-01-06",
"pages": "1-1"
},
{
"id": "authors:3gkmd-rqq82",
"collection": "authors",
"collection_id": "3gkmd-rqq82",
"cite_using_url": "https://authors.library.caltech.edu/records/3gkmd-rqq82",
"type": "article",
"title": "Imaging-guided bioresorbable acoustic hydrogel microrobots",
"author": [
{
"family_name": "Han",
"given_name": "Hong",
"orcid": "0000-0002-2852-8662",
"clpid": "Han-Hong"
},
{
"family_name": "Ma",
"given_name": "Xiaotian",
"orcid": "0009-0000-8357-9916",
"clpid": "Ma-Xiaotian"
},
{
"family_name": "Deng",
"given_name": "Weiting",
"orcid": "0000-0003-0984-8027",
"clpid": "Deng-Weiting"
},
{
"family_name": "Zhang",
"given_name": "Junhang",
"orcid": "0000-0002-7847-3102"
},
{
"family_name": "Tang",
"given_name": "Songsong",
"orcid": "0000-0003-4699-6563",
"clpid": "Tang-Songsong"
},
{
"family_name": "Pak",
"given_name": "On Shun",
"orcid": "0000-0003-1510-7049"
},
{
"family_name": "Zhu",
"given_name": "Lailai",
"orcid": "0000-0002-3443-0709"
},
{
"family_name": "Criado-Hidalgo",
"given_name": "Ernesto",
"orcid": "0000-0001-9086-9129",
"clpid": "Criado-Hidalgo-Ernesto"
},
{
"family_name": "Gong",
"given_name": "Chen",
"orcid": "0000-0002-6262-704X"
},
{
"family_name": "Karshalev",
"given_name": "Emil",
"orcid": "0000-0001-7802-6153",
"clpid": "Karshalev-Emil"
},
{
"family_name": "Yoo",
"given_name": "Jounghyun",
"orcid": "0000-0003-4253-2382"
},
{
"family_name": "You",
"given_name": "Ming",
"clpid": "You-Ming"
},
{
"family_name": "Liu",
"given_name": "Ann",
"orcid": "0000-0002-0908-3506",
"clpid": "Liu-Ann"
},
{
"family_name": "Wang",
"given_name": "Canran",
"orcid": "0000-0003-3297-9041",
"clpid": "Wang-Canran"
},
{
"family_name": "Shen",
"given_name": "Hao K.",
"orcid": "0000-0003-2687-0736",
"clpid": "Shen-Hao-K"
},
{
"family_name": "Patel",
"given_name": "Payal N.",
"clpid": "Patel-Payal-N"
},
{
"family_name": "Hays",
"given_name": "Claire L.",
"orcid": "0009-0006-9312-9816",
"clpid": "Hays-Claire-L"
},
{
"family_name": "Gunnarson",
"given_name": "Peter J.",
"orcid": "0000-0002-4437-5379",
"clpid": "Gunnarson-Peter-J"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Zhang",
"given_name": "Yang",
"orcid": "0000-0002-4533-4325",
"clpid": "Zhang-Yang"
},
{
"family_name": "Dabiri",
"given_name": "John Oluseun",
"orcid": "0000-0002-6722-9008",
"clpid": "Dabiri-J-O"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Shapiro",
"given_name": "Mikhail G.",
"orcid": "0000-0002-0291-4215",
"clpid": "Shapiro-M-G"
},
{
"family_name": "Wu",
"given_name": "Di",
"orcid": "0000-0002-6848-668X",
"clpid": "Wu-Di"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"orcid": "0000-0003-1527-3020"
},
{
"family_name": "Greer",
"given_name": "Julia R.",
"orcid": "0000-0002-9675-1508",
"clpid": "Greer-J-R"
},
{
"family_name": "Gao",
"given_name": "Wei",
"orcid": "0000-0002-8503-4562",
"clpid": "Gao-Wei"
}
],
"abstract": "Micro- and nanorobots excel in navigating the intricate and often inaccessible areas of the human body, offering immense potential for applications such as disease diagnosis, precision drug delivery, detoxification, and minimally invasive surgery. Despite their promise, practical deployment faces hurdles, including achieving stable propulsion in complex in vivo biological environments, real-time imaging and localization through deep tissue, and precise remote control for targeted therapy and ensuring high therapeutic efficacy. To overcome these obstacles, we introduce a hydrogel-based, imaging-guided, bioresorbable acoustic microrobot (BAM) designed to navigate the human body with high stability. Constructed using two-photon polymerization, a BAM comprises magnetic nanoparticles and therapeutic agents integrated into its hydrogel matrix for precision control and drug delivery. The microrobot features an optimized surface chemistry with a hydrophobic inner layer to substantially enhance microbubble retention in biofluids with multiday functionality and a hydrophilic outer layer to minimize aggregation and promote timely degradation. The dual-opening bubble-trapping cavity design enables a BAM to maintain consistent and efficient acoustic propulsion across a range of biological fluids. Under focused ultrasound stimulation, the entrapped microbubbles oscillate and enhance the contrast for real-time ultrasound imaging, facilitating precise tracking and control of BAM movement through wireless magnetic navigation. Moreover, the hydrolysis-driven biodegradability of BAMs ensures its safe dissolution after treatment, posing no risk of long-term residual harm. Thorough in vitro and in vivo experimental evidence demonstrates the promising capabilities of BAMs in biomedical applications. This approach shows promise for advancing minimally invasive medical interventions and targeted therapeutic delivery.",
"doi": "10.1126/scirobotics.adp3593",
"issn": "2470-9476",
"publisher": "American Association for the Advancement of Science",
"publication": "Science Robotics",
"publication_date": "2024-12",
"series_number": "97",
"volume": "9",
"issue": "97"
},
{
"id": "authors:p2ras-0k310",
"collection": "authors",
"collection_id": "p2ras-0k310",
"cite_using_url": "https://authors.library.caltech.edu/records/p2ras-0k310",
"type": "article",
"title": "Clinical translation of photoacoustic imaging",
"author": [
{
"family_name": "Park",
"given_name": "Jeongwoo",
"orcid": "0000-0003-3366-2329"
},
{
"family_name": "Choi",
"given_name": "Seongwook",
"orcid": "0000-0001-9774-058X"
},
{
"family_name": "Knieling",
"given_name": "Ferdinand",
"orcid": "0000-0002-3535-2626"
},
{
"family_name": "Clingman",
"given_name": "Bryan"
},
{
"family_name": "Bohndiek",
"given_name": "Sarah"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"orcid": "0000-0001-7249-1257"
}
],
"abstract": "Photoacoustic imaging (PAI), also known as optoacoustic imaging, is a promising biomedical imaging technique that combines the benefits of rich optical contrast and high ultrasonic spatial resolution to overcome the limited penetration depth of light in living subjects. Basic biomedical research conducted with PAI in preclinical studies has generated much interest and shown outstanding potential for clinical and commercial translation. PAI has captured morphological, functional and molecular information in studies of living animals and humans, providing intrinsic clinical indicators from early diagnosis through to treatment monitoring. This Review presents the fundamentals of PAI technology and various clinical PAI systems and addresses key findings from pilot and clinical patient studies of human organ systems. The Review also discusses technical and non-technical challenges in clinical scenarios, emphasizes the importance of standardization in accelerating clinical translation, and summarizes the current state of the PAI regulatory process.
",
"doi": "10.1038/s44222-024-00240-y",
"issn": "2731-6092",
"publisher": "Nature Publishing Group",
"publication": "Nature Reviews Bioengineering",
"publication_date": "2024-09-26"
},
{
"id": "authors:jk7vz-9qn95",
"collection": "authors",
"collection_id": "jk7vz-9qn95",
"cite_using_url": "https://authors.library.caltech.edu/records/jk7vz-9qn95",
"type": "article",
"title": "Single-pulse ultrafast real-time simultaneous planar imaging of femtosecond laser-nanoparticle dynamics in flames",
"author": [
{
"family_name": "Mishra",
"given_name": "Yogeshwar Nath",
"orcid": "0000-0003-2063-2200"
},
{
"family_name": "Wang",
"given_name": "Peng",
"orcid": "0000-0002-6302-8495",
"clpid": "Wang-Peng"
},
{
"family_name": "Bauer",
"given_name": "Florian J.",
"orcid": "0000-0001-8590-1841"
},
{
"family_name": "Gudipati",
"given_name": "Murthy S.",
"orcid": "0000-0001-5992-373X"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The creation of carbonaceous nanoparticles and their dynamics in hydrocarbon flames are still debated in environmental, combustion, and material sciences. In this study, we introduce single-pulse femtosecond laser sheet-compressed ultrafast photography (fsLS-CUP), an ultrafast imaging technique specifically designed to shed light on and capture ultrafast dynamics stemming from interactions between femtosecond lasers and nanoparticles in flames in a single-shot. fsLS-CUP enables the first-time real-time billion frames-per-second (Gfps) simultaneous two-dimensional (2D) imaging of laser-induced fluorescence (LIF) and laser-induced heating (LIH) that are originated from polycyclic aromatic hydrocarbons (PAHs) and soot particles, respectively. Furthermore, fsLS-CUP provides the real-time spatiotemporal map of femtosecond laser-soot interaction as elastic light scattering (ELS) at an astonishing 250 Gfps. In contrast to existing single-shot ultrafast imaging approaches, which are limited to millions of frames per second only and require multiple laser pulses, our method employs only a single pulse and captures the entire dynamics of laser-induced signals at hundreds of Gfps. Using a single pulse does not change the optical properties of nanoparticles for a following pulse, thus allowing reliable spatiotemporal mapping. Moreover, we found that particle inception and growth are derived from precursors. In essence, as an imaging modality, fsLS-CUP offers ultrafast 2D diagnostics, contributing to the fundamental understanding of nanoparticle’s inception and broader applications across different fields, such as material science and biomedical engineering.
",
"doi": "10.1038/s41377-024-01588-x",
"issn": "2047-7538",
"publisher": "Nature Publishing Group",
"publication": "Light: Science and Applications",
"publication_date": "2024-08-29",
"series_number": "1",
"volume": "13",
"issue": "1",
"pages": "221"
},
{
"id": "authors:41kk8-g8m19",
"collection": "authors",
"collection_id": "41kk8-g8m19",
"cite_using_url": "https://authors.library.caltech.edu/records/41kk8-g8m19",
"type": "article",
"title": "Sharp-peaked lanthanide nanocrystals for near-infrared photoacoustic multiplexed differential imaging",
"author": [
{
"family_name": "Loh",
"given_name": "Kang Yong",
"orcid": "0000-0002-0920-7003"
},
{
"family_name": "Li",
"given_name": "Lei S.",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei-S"
},
{
"family_name": "Fan",
"given_name": "Jingyue",
"orcid": "0000-0003-4987-7025"
},
{
"family_name": "Goh",
"given_name": "Yi Yiing",
"orcid": "0000-0002-2061-0311"
},
{
"family_name": "Liew",
"given_name": "Weng Heng"
},
{
"family_name": "Davis",
"given_name": "Samuel",
"orcid": "0000-0002-0871-8880",
"clpid": "Davis-Samuel"
},
{
"family_name": "Zhang",
"given_name": "Yide",
"orcid": "0000-0002-9463-3970",
"clpid": "Zhang-Yide"
},
{
"family_name": "Li",
"given_name": "Kai",
"orcid": "0000-0003-1664-5439"
},
{
"family_name": "Liu",
"given_name": "Jie"
},
{
"family_name": "Liang",
"given_name": "Liangliang",
"orcid": "0000-0003-4958-3801"
},
{
"family_name": "Feng",
"given_name": "Minjun",
"orcid": "0000-0002-3504-7699"
},
{
"family_name": "Yang",
"given_name": "Ming",
"orcid": "0000-0001-6555-3739"
},
{
"family_name": "Zhang",
"given_name": "Hang",
"orcid": "0000-0001-5113-6125"
},
{
"family_name": "Ma",
"given_name": "Ping'an",
"orcid": "0000-0003-4198-5240"
},
{
"family_name": "Feng",
"given_name": "Guangxue",
"orcid": "0000-0003-4344-3517"
},
{
"family_name": "Mu",
"given_name": "Zhao"
},
{
"family_name": "Gao",
"given_name": "Weibo",
"orcid": "0000-0003-3971-621X"
},
{
"family_name": "Sum",
"given_name": "Tze Chien",
"orcid": "0000-0003-4049-2719"
},
{
"family_name": "Liu",
"given_name": "Bin",
"orcid": "0000-0002-0956-2777"
},
{
"family_name": "Lin",
"given_name": "Jun",
"orcid": "0000-0001-9572-2134"
},
{
"family_name": "Yao",
"given_name": "Kui",
"orcid": "0000-0001-5875-4815"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Liu",
"given_name": "Xiaogang",
"orcid": "0000-0003-2517-5790"
}
],
"abstract": "Photoacoustic tomography offers a powerful tool to visualize biologically relevant molecules and understand processes within living systems at high resolution in deep tissue, facilitated by the conversion of incident photons into low-scattering acoustic waves through non-radiative relaxation. Although current endogenous and exogenous photoacoustic contrast agents effectively enable molecular imaging within deep tissues, their broad absorption spectra in the visible to near-infrared (NIR) range limit photoacoustic multiplexed imaging. Here, we exploit the distinct ultrasharp NIR absorption peaks of lanthanides to engineer a series of NIR photoacoustic nanocrystals. This engineering involves precise host and dopant material composition, yielding nanocrystals with sharply peaked photoacoustic absorption spectra (~3.2 nm width) and a ~10-fold enhancement in NIR optical absorption for efficient deep tissue imaging. By combining photoacoustic tomography with these engineered nanocrystals, we demonstrate photoacoustic multiplexed differential imaging with substantially decreased background signals and enhanced precision and contrast.
",
"doi": "10.1038/s43246-024-00605-1",
"issn": "2662-4443",
"publisher": "Nature Publishing Group",
"publication": "Communications Materials",
"publication_date": "2024-08-21",
"series_number": "1",
"volume": "5",
"issue": "1",
"pages": "164"
},
{
"id": "authors:hr009-fn822",
"collection": "authors",
"collection_id": "hr009-fn822",
"cite_using_url": "https://authors.library.caltech.edu/records/hr009-fn822",
"type": "article",
"title": "Quantum mechanical modeling of the multi-stage Stern\u2013Gerlach experiment conducted by Frisch and Segr\u00e8",
"author": [
{
"family_name": "Kahraman",
"given_name": "S. S\u00fcleyman",
"orcid": "0000-0001-8154-367X",
"clpid": "Kahraman-S-S\u00fcleyman"
},
{
"family_name": "Titimbo",
"given_name": "Kelvin",
"orcid": "0000-0002-4700-3482",
"clpid": "Titimbo-Kelvin"
},
{
"family_name": "He",
"given_name": "Zhe",
"orcid": "0000-0002-8525-3650",
"clpid": "He-Zhe"
},
{
"family_name": "Shen",
"given_name": "Jung-Tsung",
"orcid": "0000-0001-7737-8886",
"clpid": "Shen-Jung-Tsung"
},
{
"family_name": "Wang",
"given_name": "Lihong V",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "\n
The multi-stage Stern–Gerlach experiment conducted by Frisch and Segrè includes two cascaded quantum measurements with a nonadiabatic flipper in between. The Frisch and Segrè experiment has been modeled analytically by Majorana without the nuclear effect and subsequently revised by Rabi with the hyperfine interaction. However, the theoretical predictions do not match the experimental observation accurately. Here, we numerically solve the standard quantum mechanical model, via the von Neumann equation, including the hyperfine interaction for the time evolution of the spin. Thus far, the coefficients of determination from the standard quantum mechanical model without using free parameters are still low, indicating a mismatch between the theory and the experiment. Non-standard variants that improve the match are explored for discussion.
\n
\n
\n
\n
Strain elastography and shear wave elastography are two commonly used methods to quantify cervical elasticity. However, the absence of stress information in strain elastography causes difficulty in comparing elasticities acquired in different sessions, and the robustness of shear wave elastography tends to be compromised by the high inhomogeneity of cervical tissue. Objective: To overcome these limitations, we develop a quantitative cervical elastography system by adding a stress sensor to a clinically used transvaginal ultrasound imaging system. Methods: In an imaging session, we use the ultrasound system to record the cervical deformation in B-mode images and use the stress sensor to record the probe-surface stress simultaneously. We develop a feature-tracking algorithm to quantify the deformation automatically and calculate the strain. Then we estimate the cervical Young's modulus through stress-strain linear regression. Results: In phantom experiments, we demonstrate the elastography system's high accuracy (alignment with the quasi-static compression method, p-value = 0.369 > 0.05), robustness (alignment between 60°- and 90°-contact measurements, p- value = 0.638 > 0.05), repeatability (consistency of single sonographers' measurements, coefficient of variation < 0.06), and reproducibility (alignment between two sonographers' measurements, Pearson correlation coefficient = 0.981). Applying it to pregnant participants, we observe significant softening of the cervix during pregnancy ( p- value < 0.001) with the cervical Young's modulus decreasing 3.95% per week. We estimate that geometric mean values of cervical Young's moduli during the first (11 to 13 weeks), second, and third trimesters are 13.07 kPa, 7.59 kPa, and 4.40 kPa, respectively. Conclusion: The proposed system is accurate, robust, and safe, and enables longitudinal measurements and comparisons between examiners. Significance: The system applies to different ultrasound machines with minor software updates, which allows for studies of cervical softening patterns in pregnancy for larger populations, facilitating insights into conditions such as preterm birth.
\n
\n
\n
\n
\n
Quantum imaging holds potential benefits over classical imaging but has faced challenges such as poor signal-to-noise ratios, low resolvable pixel counts, difficulty in imaging biological organisms, and inability to quantify full birefringence properties. Here, we introduce quantum imaging by coincidence from entanglement (ICE), using spatially and polarization-entangled photon pairs to overcome these challenges. With spatial entanglement, ICE offers higher signal-to-noise ratios, greater resolvable pixel counts, and the ability to image biological organisms. With polarization entanglement, ICE provides quantitative quantum birefringence imaging capability, where both the phase retardation and the principal refractive index axis angle of an object can be remotely and instantly quantified without changing the polarization states of the photons incident on the object. Furthermore, ICE enables 25 times greater suppression of stray light than classical imaging. ICE has the potential to pave the way for quantum imaging in diverse fields, such as life sciences and remote sensing.
\n
\n
We thank Y. Zhao for contributing to the universal calibration. This work was supported in part by National Institutes of Health grants R01 EB028277, U01 EB029823 and R35 CA220436 (Outstanding Investigator Award). The computations presented here were conducted at the Resnick High Performance Computing Center, a facility supported by the Resnick Sustainability Institute at the California Institute of Technology.
",
"doi": "10.1038/s41551-023-01149-4",
"issn": "2157-846X",
"publisher": "Nature Publishing Group",
"publication": "Nature Biomedical Engineering",
"publication_date": "2023-11-30"
},
{
"id": "authors:9kn8s-1sz04",
"collection": "authors",
"collection_id": "9kn8s-1sz04",
"cite_using_url": "https://authors.library.caltech.edu/records/9kn8s-1sz04",
"type": "article",
"title": "Photoacoustic vector tomography for deep haemodynamic imaging",
"author": [
{
"family_name": "Zhang",
"given_name": "Yang",
"orcid": "0000-0002-4533-4325",
"clpid": "Zhang-Yang"
},
{
"family_name": "Olick-Gibson",
"given_name": "Joshua",
"clpid": "Olick-Gibson-Joshua"
},
{
"family_name": "Khadria",
"given_name": "Anjul",
"orcid": "0000-0002-9771-3650",
"clpid": "Khadria-Anjul"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Imaging deep haemodynamics non-invasively remains a quest. Although optical imaging techniques can be used to measure blood flow, they are generally limited to imaging within \u223c1\u2009mm below the skin's surface. Here we show that such optical diffusion limit can be broken through by leveraging the spatial heterogeneity of blood and its photoacoustic contrast. Specifically, successive single-shot wide-field photoacoustic images of blood vessels can be used to visualize the frame-to-frame propagation of blood and to estimate blood flow speed and direction pixel-wise. The method, which we named photoacoustic vector tomography (PAVT), allows for the quantification of haemodynamics in veins more than 5\u2009mm deep, as we show for regions in the hands and arms of healthy volunteers. PAVT may offer advantages for the diagnosis and monitoring of vascular diseases and for the mapping of the function of the circulatory system.
",
"doi": "10.1038/s41551-023-01148-5",
"issn": "2157-846X",
"publisher": "Nature Publishing Group",
"publication": "Nature Biomedical Engineering",
"publication_date": "2023-11-30"
},
{
"id": "authors:y9v05-5qq64",
"collection": "authors",
"collection_id": "y9v05-5qq64",
"cite_using_url": "https://authors.library.caltech.edu/records/y9v05-5qq64",
"type": "article",
"title": "Label-free biomedical optical imaging",
"author": [
{
"family_name": "Shaked",
"given_name": "Natan T.",
"orcid": "0000-0003-4080-839X",
"clpid": "Shaked-Natan-T"
},
{
"family_name": "Boppart",
"given_name": "Stephen A.",
"orcid": "0000-0002-9386-5630",
"clpid": "Boppart-Stephen-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Popp",
"given_name": "J\u00fcrgen",
"orcid": "0000-0003-4257-593X",
"clpid": "Popp-J\u00fcrgen"
}
],
"abstract": "Label-free optical imaging employs natural and non-destructive approaches to visualize biomedical samples for both biological assays and clinical diagnosis. At present, this field revolves around multiple technology-oriented communities, each with a specific focus on a particular modality, despite the existence of shared challenges and applications. As a result, biologists or clinical researchers who require label-free imaging are often not aware of the most appropriate modality to use. This Review presents a comprehensive overview of, and comparison among, different label-free imaging modalities and discusses common challenges and applications. We expect this Review to facilitate collaborative interactions between imaging communities, push the field forwards and foster technological advancements and biophysical discoveries, as well as facilitate new avenues in clinical detection, diagnosis and monitoring of diseases.
",
"doi": "10.1038/s41566-023-01299-6",
"issn": "1749-4885",
"publisher": "Nature Publishing Group",
"publication": "Nature Photonics",
"publication_date": "2023-11-16"
},
{
"id": "authors:7hjnp-k4c43",
"collection": "authors",
"collection_id": "7hjnp-k4c43",
"cite_using_url": "https://authors.library.caltech.edu/records/7hjnp-k4c43",
"type": "article",
"title": "Photoacoustic imaging of the dynamics of a dye-labeled IgG4 monoclonal antibody in subcutaneous tissue reveals a transient decrease in murine blood oxygenation under anesthesia",
"author": [
{
"family_name": "Khadria",
"given_name": "Anjul",
"orcid": "0000-0002-9771-3650",
"clpid": "Khadria-Anjul"
},
{
"family_name": "Paavola",
"given_name": "Chad D.",
"orcid": "0000-0001-6952-1400",
"clpid": "Paavola-Chad-D"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-Konstantin-I"
},
{
"family_name": "Brown-Augsburger",
"given_name": "Patricia L.",
"orcid": "0000-0002-6444-4749",
"clpid": "Brown-Augsburger-Patricia-L"
},
{
"family_name": "Grealish",
"given_name": "Patrick F.",
"clpid": "Grealish-Patrick-F"
},
{
"family_name": "Lozano",
"given_name": "Emmanuel",
"clpid": "Lozano-Emmanuel"
},
{
"family_name": "Blankenship",
"given_name": "Ross L.",
"clpid": "Blankenship-Ross-L"
},
{
"family_name": "Cao",
"given_name": "Rui",
"clpid": "Cao-Rui"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Beals",
"given_name": "John M.",
"orcid": "0000-0002-7494-9126",
"clpid": "Beals-John-M"
},
{
"family_name": "Oladipupo",
"given_name": "Sunday S.",
"clpid": "Oladipupo-Sunday-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "\n
Aim
\n
The aim of this research is to understand the dynamics of monoclonal antibodies at the injection site as well as how the antibody itself affects the functional characteristics of the injection site [e.g., blood oxygen saturation (sO2)].
\n
Approach
\n
\n
We employed triple-wavelength equipped functional photoacoustic imaging to study the dynamics of dye-labeled and unlabeled monoclonal antibodies at the site of injection in a mouse ear. We injected a near-infrared dye-labeled (and unlabeled) human IgG4 isotype control antibody into the subcutaneous space in mouse ears to analyze the injection site dynamics and quantify molecular movement, as well as its effect on local hemodynamics.
\n
\n
Results
\n
We performed pharmacokinetic studies of the antibody in different regions of the mouse body to show that dye labeling does not alter the pharmacokinetic characteristics of the antibody and that mouse ear is a viable model for these initial studies. We explored the movement of the antibody in the interstitial space to show that the bolus area grows by ∼300 % over 24 h. We discovered that injection of the antibody transiently reduces the local sO2 levels in mice after prolonged anesthesia without affecting the total hemoglobin content and oxygen extraction fraction.
\n
Conclusions
\n
\n
This finding on local oxygen saturation opens a new avenue of study on the functional effects of monoclonal antibody injections. We also show the suitability of the mouse ear model to study antibody dynamics through high-resolution imaging techniques. We quantified the movement of antibodies at the injection site caused by the interstitial fluid, which could be helpful for designing antibodies with tailored absorption speeds in the future.
\n
We use a theory termed co-quantum dynamics (CQD) to numerically model spin flip in the multi-stage Stern\u2013Gerlach (SG) experiment conducted by R. Frisch and E. Segr\u00e8. This experiment consists of two SG apparatuses separated by an inner rotation chamber that varies the fraction of spin flip. To this day, quantum mechanical treatments inadequately predict the Frisch\u2013Segr\u00e8 experiment. Here, we account for electron-nuclear interactions according to CQD and solve the associated Schr\u00f6dinger equation. Our simulation utilizes a branching condition to predict the collapse of electron spins, and the outcome agrees with the Frisch\u2013Segr\u00e8 experimental observation and supports CQD as a potential model for electron spin evolution and collapse.
",
"doi": "10.1088/1361-6455/acef83",
"issn": "0953-4075",
"publisher": "IOP Publishing",
"publication": "Journal of Physics B: Atomic, Molecular and Optical Physics",
"publication_date": "2023-10-28",
"series_number": "20",
"volume": "56",
"issue": "20",
"pages": "205005"
},
{
"id": "authors:qqm8q-kv142",
"collection": "authors",
"collection_id": "qqm8q-kv142",
"cite_using_url": "https://authors.library.caltech.edu/records/qqm8q-kv142",
"type": "article",
"title": "Numerical modeling of the multi-stage Stern\u2013Gerlach experiment by Frisch and Segr\u00e8 using co-quantum dynamics via the Bloch equation",
"author": [
{
"family_name": "Titimbo",
"given_name": "Kelvin",
"orcid": "0000-0002-4700-3482",
"clpid": "Titimbo-Kelvin"
},
{
"family_name": "Garrett",
"given_name": "David C.",
"orcid": "0000-0002-9747-8494",
"clpid": "Garrett-David-C"
},
{
"family_name": "Kahraman",
"given_name": "S. S\u00fcleyman",
"orcid": "0000-0001-8154-367X",
"clpid": "Kahraman-S-S\u00fcleyman"
},
{
"family_name": "He",
"given_name": "Zhe",
"orcid": "0000-0002-8525-3650",
"clpid": "He-Zhe"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We numerically study the spin flip in the Frisch\u2013Segr\u00e8 experiment, the first multi-stage Stern\u2013Gerlach experiment, within the context of the novel co-quantum dynamics (CQD) theory. We model the middle stage responsible for spin rotation by sampling the atoms with the Monte Carlo method and solving the dynamics of the electron and nuclear magnetic moments numerically according to the Bloch equation. The simulation shows that CQD closely reproduces, without using any fitting parameters, the experimental observations reported by Frisch and Segr\u00e8 in 1933, which have so far lacked theoretical predictions.
",
"doi": "10.1088/1361-6455/acf971",
"issn": "0953-4075",
"publisher": "IOP Publishing",
"publication": "Journal of Physics B: Atomic, Molecular and Optical Physics",
"publication_date": "2023-10-28",
"series_number": "20",
"volume": "56",
"issue": "20",
"pages": "205004"
},
{
"id": "authors:xnswt-49648",
"collection": "authors",
"collection_id": "xnswt-49648",
"cite_using_url": "https://authors.library.caltech.edu/records/xnswt-49648",
"type": "article",
"title": "An ultrahigh-fidelity 3D holographic display using scattering to homogenize the angular spectrum",
"author": [
{
"family_name": "Yang",
"given_name": "Jiamiao",
"orcid": "0000-0003-0006-8411",
"clpid": "Yang-Jiamiao"
},
{
"family_name": "Li",
"given_name": "Lei S.",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei-S"
},
{
"family_name": "He",
"given_name": "Qiaozhi",
"orcid": "0000-0002-9475-8319",
"clpid": "He-Qiaozhi"
},
{
"family_name": "Li",
"given_name": "Chengmingyue",
"clpid": "Li-Chengmingyue"
},
{
"family_name": "Qu",
"given_name": "Yuan",
"orcid": "0000-0001-7498-133X",
"clpid": "Qu-Yuan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A three-dimensional (3D) holographic display (3DHD) can preserve all the volumetric information about an object. However, the poor fidelity of 3DHD constrains its applications. Here, we present an ultrahigh-fidelity 3D holographic display that uses scattering for homogenization of angular spectrum. A scattering medium randomizes the incident photons and homogenizes the angular spectrum distribution. The redistributed field is recorded by a photopolymer film with numerous modulation modes and a half-wavelength scale pixel size. We have experimentally improved the contrast of a focal spot to 6 \u00d7 10\u2076 and tightened its spatial resolution to 0.5 micrometers, respectively ~300 and 4.4 times better than digital approaches. By exploiting the spatial multiplexing ability of the photopolymer and the transmission channel selection capability of the scattering medium, we have realized a dynamic holographic display of 3D spirals consisting of 20 foci across 1 millimeter \u00d7 1 millimeter \u00d7 26 millimeters with uniform intensity.
",
"doi": "10.1126/sciadv.adi9987",
"pmcid": "PMC10569707",
"issn": "2375-2548",
"publisher": "American Association for the Advancement of Science",
"publication": "Science Advances",
"publication_date": "2023-10-13",
"series_number": "41",
"volume": "9",
"issue": "41",
"pages": "eadi9987"
},
{
"id": "authors:qddh7-b8b47",
"collection": "authors",
"collection_id": "qddh7-b8b47",
"cite_using_url": "https://authors.library.caltech.edu/records/qddh7-b8b47",
"type": "article",
"title": "Polarization patterns of light enable geolocalization in oceans",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The deep ocean, characterized by its immense depths and absence of global positioning system (GPS) functionality, presents considerable challenges for search and rescue missions. Inspired by the geolocalization capabilities of migratory marine animals, Bai et al. present a novel method for underwater geolocalization using the polarization patterns of light in the underwater environment. Emulating a sextant using these underwater polarization patterns, the study determines geolocation in underwater settings. Despite prior skepticism, even in low-visibility waters, these patterns, learned through a deep neural network, provide geolocation accuracies of 55\u2009km at 8\u2009m and 255\u2009km at 50\u2009m. This pioneering approach offers implications for search and rescue and hints at navigation mechanisms in marine animals.
",
"doi": "10.1038/s41377-023-01279-z",
"pmcid": "PMC10511461",
"issn": "2047-7538",
"publisher": "Nature Publishing Group",
"publication": "Light: Science & Applications",
"publication_date": "2023-09-20",
"volume": "12",
"pages": "240"
},
{
"id": "authors:wa93w-xgx73",
"collection": "authors",
"collection_id": "wa93w-xgx73",
"cite_using_url": "https://authors.library.caltech.edu/records/wa93w-xgx73",
"type": "article",
"title": "A review of a strategic roadmapping exercise to advance clinical translation of photoacoustic imaging: From current barriers to future adoption",
"author": [
{
"family_name": "Assi",
"given_name": "Hisham",
"orcid": "0000-0002-0734-1401",
"clpid": "Assi-Hisham"
},
{
"family_name": "Cao",
"given_name": "Rui",
"clpid": "Cao-Rui"
},
{
"family_name": "Castelino",
"given_name": "Madhura",
"orcid": "0000-0002-2724-0122"
},
{
"family_name": "Cox",
"given_name": "Ben",
"orcid": "0000-0001-7296-4093"
},
{
"family_name": "Gilbert",
"given_name": "Fiona J.",
"orcid": "0000-0002-0124-9962"
},
{
"family_name": "Gr\u00f6hl",
"given_name": "Janek",
"orcid": "0000-0002-5332-4856"
},
{
"family_name": "Gurusamy",
"given_name": "Kurinchi",
"orcid": "0000-0002-0313-9134"
},
{
"family_name": "Hacker",
"given_name": "Lina",
"orcid": "0000-0001-5160-0952"
},
{
"family_name": "Ivory",
"given_name": "Aoife M.",
"orcid": "0000-0001-8160-0160"
},
{
"family_name": "Joseph",
"given_name": "James",
"orcid": "0000-0001-6270-2559"
},
{
"family_name": "Knieling",
"given_name": "Ferdinand",
"orcid": "0000-0002-3535-2626"
},
{
"family_name": "Leahy",
"given_name": "Martin J.",
"orcid": "0000-0003-1558-4574"
},
{
"family_name": "Lilaj",
"given_name": "Ledia",
"orcid": "0000-0001-8222-0397"
},
{
"family_name": "Manohar",
"given_name": "Srirang",
"orcid": "0000-0002-2986-6671"
},
{
"family_name": "Meglinski",
"given_name": "Igor",
"orcid": "0000-0002-7613-8191"
},
{
"family_name": "Moran",
"given_name": "Carmel",
"orcid": "0000-0002-2105-2948"
},
{
"family_name": "Murray",
"given_name": "Andrea",
"orcid": "0000-0001-9244-2882"
},
{
"family_name": "Oraevsky",
"given_name": "Alexander A.",
"orcid": "0000-0002-9212-6211"
},
{
"family_name": "Pagel",
"given_name": "Mark D.",
"orcid": "0000-0002-8109-3995"
},
{
"family_name": "Pramanik",
"given_name": "Manojit",
"orcid": "0000-0003-2865-5714"
},
{
"family_name": "Raymond",
"given_name": "Jason",
"orcid": "0000-0002-6367-9431"
},
{
"family_name": "Kuniyil Ajith Singh",
"given_name": "Mithun",
"orcid": "0000-0001-8670-6335"
},
{
"family_name": "Vogt",
"given_name": "William C.",
"orcid": "0000-0002-0799-1412"
},
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Yang",
"given_name": "Shufan"
},
{
"family_name": "Members of IPASC",
"clpid": "Members-of-IASPC"
},
{
"family_name": "Bohndiek",
"given_name": "Sarah E.",
"orcid": "0000-0003-0371-8635"
}
],
"abstract": "Photoacoustic imaging (PAI), also referred to as optoacoustic imaging, has shown promise in early-stage clinical trials in a range of applications from inflammatory diseases to cancer. While the first PAI systems have recently received regulatory approvals, successful adoption of PAI technology into healthcare systems for clinical decision making must still overcome a range of barriers, from education and training to data acquisition and interpretation. The International Photoacoustic Standardisation Consortium (IPASC) undertook an community exercise in 2022 to identify and understand these barriers, then develop a roadmap of strategic plans to address them. Here, we outline the nature and scope of the barriers that were identified, along with short-, medium- and long-term community efforts required to overcome them, both within and beyond the IPASC group.
",
"doi": "10.1016/j.pacs.2023.100539",
"pmcid": "PMC10432856",
"issn": "2213-5979",
"publisher": "Elsevier",
"publication": "Photoacoustics",
"publication_date": "2023-08",
"volume": "32",
"pages": "100539"
},
{
"id": "authors:mfdw8-kmx14",
"collection": "authors",
"collection_id": "mfdw8-kmx14",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230725-857385000.69",
"type": "article",
"title": "A method for the geometric calibration of ultrasound transducer arrays with arbitrary geometries",
"author": [
{
"family_name": "Sastry",
"given_name": "Karteekeya",
"orcid": "0000-0001-7659-4878",
"clpid": "Sastry-Karteekeya"
},
{
"family_name": "Zhang",
"given_name": "Yang",
"orcid": "0000-0002-4533-4325",
"clpid": "Zhang-Yang-MED"
},
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Luo",
"given_name": "Yilin",
"orcid": "0000-0002-4611-3049",
"clpid": "Luo-Yilin"
},
{
"family_name": "Tong",
"given_name": "Xin",
"clpid": "Tong-Xin"
},
{
"family_name": "Na",
"given_name": "Shuai",
"orcid": "0000-0003-2083-0047",
"clpid": "Na-Shuai"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Geometric calibration of ultrasound transducer arrays is critical to optimizing the performance of photoacoustic computed tomography (PACT) systems. We present a geometric calibration method that is applicable to a wide range of PACT systems. We obtain the speed of sound and point source locations using surrogate methods, which results in a linear problem in the transducer coordinates. We characterize the estimation error, which informs our choice of the point source arrangement. We demonstrate our method in a three-dimensional PACT system and show that our method improves the contrast-to-noise ratio, the size, and the spread of point source reconstructions by (80 \u00b1 19)%, (19 \u00b1 3)%, and (7 \u00b1 1)%, respectively. We reconstruct the images of a healthy human breast before and after calibration and find that the calibrated image reveals vasculatures that were previously invisible. Our work introduces a method for geometric calibration in PACT and paves the way for improving PACT image quality.",
"doi": "10.1016/j.pacs.2023.100520",
"pmcid": "PMC10329181",
"issn": "2213-5979",
"publisher": "Elsevier",
"publication": "Photoacoustics",
"publication_date": "2023-08",
"volume": "32",
"pages": "100520"
},
{
"id": "authors:1pv48-s2w66",
"collection": "authors",
"collection_id": "1pv48-s2w66",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230518-332288000.3",
"type": "article",
"title": "Multi-stage Stern\u2013Gerlach experiment modeled",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In the classic multi-stage Stern\u2013Gerlach experiment conducted by Frisch and Segr\u00e8, the Majorana (Landau\u2013Zener) and Rabi formulae diverge far from the experimental observation while the physical mechanism for electron-spin collapse remains unidentified. Here, introducing the physical co-quantum concept provides a plausible physical mechanism and predicts the experimental observation in absolute units without fitting (i.e. no parameters adjusted), with a p-value less than one per million, which is the probability that the co-quantum theory happens to match the experimental observation purely by chance. Further, the co-quantum concept is corroborated by exactly statistically reproducing the wave function, density operator, and uncertainty relation for electron spin in Stern\u2013Gerlach experiments.",
"doi": "10.1088/1361-6455/acc149",
"issn": "0953-4075",
"publisher": "Institute of Physics",
"publication": "Journal of Physics B: Atomic, Molecular and Optical Physics",
"publication_date": "2023-05-28",
"series_number": "10",
"volume": "56",
"issue": "10",
"pages": "Art. No. 105001"
},
{
"id": "authors:knecv-ttb21",
"collection": "authors",
"collection_id": "knecv-ttb21",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230328-708572000.65",
"type": "article",
"title": "Single\u2010Shot Reconfigurable Femtosecond Imaging of Ultrafast Optical Dynamics",
"author": [
{
"family_name": "Wang",
"given_name": "Peng",
"orcid": "0000-0002-6302-8495",
"clpid": "Wang-Peng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Understanding ultrafast dynamics in the femtosecond timescale plays a pivotal role in fundamental research and technology innovation. Spatiotemporal observation of those events in real-time requires imaging speeds greater than 10\u00b9\u00b2 frames per second (fps), far beyond the fundamental speed limits of the ubiquitous semiconductor sensor technologies. In addition, a majority of femtosecond events are non-repeatable or difficult-to-repeat since they either work in a highly unstable nonlinear regime or require extreme or rare conditions to initiate. Therefore, the traditional pump-probe imaging approach fails since it heavily depends on precise event repetition. Single-shot ultrafast imaging emerges as the only solution; however, existing techniques cannot reach more than 15\u00d710\u00b9\u00b2 fps, and they only record an insufficient number of frames. Compressed ultrafast spectral photography (CUSP) is proposed to overcome these limitations. Here, CUSP's full design space is explored by manipulating the ultrashort optical pulse in the active illumination. Via parameter optimization, an extraordinarily fast frame rate of 219 \u00d7 10\u00b9\u00b2 fps is achieved. This implementation of CUSP is also highly flexible, allowing various combinations of imaging speeds and numbers of frames (several hundred up to 1000) to be readily deployed in diverse scientific studies, such as laser-induced transient birefringence, self-focusing, and filaments in dielectric media.",
"doi": "10.1002/advs.202207222",
"pmcid": "PMC10161092",
"issn": "2198-3844",
"publisher": "Wiley",
"publication": "Advanced Science",
"publication_date": "2023-05-05",
"series_number": "13",
"volume": "10",
"issue": "13",
"pages": "2207222"
},
{
"id": "authors:5etg8-qvz41",
"collection": "authors",
"collection_id": "5etg8-qvz41",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230519-1725000.20",
"type": "article",
"title": "Quantum microscopy of cells at the Heisenberg limit",
"author": [
{
"family_name": "He",
"given_name": "Zhe",
"orcid": "0000-0002-8525-3650",
"clpid": "He-Zhe"
},
{
"family_name": "Zhang",
"given_name": "Yide",
"orcid": "0000-0002-9463-3970",
"clpid": "Zhang-Yide"
},
{
"family_name": "Tong",
"given_name": "Xin",
"orcid": "0000-0003-2002-5638",
"clpid": "Tong-Xin"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Entangled biphoton sources exhibit nonclassical characteristics and have been applied to imaging techniques such as ghost imaging, quantum holography, and quantum optical coherence tomography. The development of wide-field quantum imaging to date has been hindered by low spatial resolutions, speeds, and contrast-to-noise ratios (CNRs). Here, we present quantum microscopy by coincidence (QMC) with balanced pathlengths, which enables super-resolution imaging at the Heisenberg limit with substantially higher speeds and CNRs than existing wide-field quantum imaging methods. QMC benefits from a configuration with balanced pathlengths, where a pair of entangled photons traversing symmetric paths with balanced optical pathlengths in two arms behave like a single photon with half the wavelength, leading to a two-fold resolution improvement. Concurrently, QMC resists stray light up to 155 times stronger than classical signals. The low intensity and entanglement features of biphotons in QMC promise nondestructive bioimaging. QMC advances quantum imaging to the microscopic level with significant improvements in speed and CNR toward the bioimaging of cancer cells. We experimentally and theoretically prove that the configuration with balanced pathlengths illuminates an avenue for quantum-enhanced coincidence imaging at the Heisenberg limit.",
"doi": "10.1038/s41467-023-38191-4",
"pmcid": "PMC10147633",
"issn": "2041-1723",
"publisher": "Nature Publishing Group",
"publication": "Nature Communications",
"publication_date": "2023-04-28",
"volume": "14",
"pages": "Art. No. 2441"
},
{
"id": "authors:4dkqv-cb302",
"collection": "authors",
"collection_id": "4dkqv-cb302",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230420-574389200.11",
"type": "article",
"title": "Real-time observation of optical rogue waves in spatiotemporally mode-locked fiber lasers",
"author": [
{
"family_name": "Te\u011fin",
"given_name": "U\u011fur",
"orcid": "0000-0002-4690-588X",
"clpid": "Te\u011fin-U\u011fur"
},
{
"family_name": "Wang",
"given_name": "Peng",
"clpid": "Wang-Peng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Fiber lasers offer tabletop nonlinear environments to mimic and study the complex dynamics of nature. Optical rogue waves, rarely occurring extreme intensity fluctuations, are one of the many subjects that can be investigated with a fiber laser cavity. Although oceanic rogue waves are a result of spatiotemporal dynamics, the single-mode nature of the fiber laser and the commonly used measurement techniques limit the optical rogue wave studies to only temporal dynamics. In this study, we overcome such limit to observe rogue wave real-time dynamics in spatiotemporally mode-locked fiber lasers by utilizing state-of-the-art compressed ultrafast photography technique. The multimode laser cavity exhibits long-tailed non-Gaussian distributions under relaxed cavity constraints. Single-shot spatiotemporal measurements of rogue events showed that, instead of noise bursts, the cavity produces clean pulses with high-quality beam profiles. Our results indicate that rogue events in spatiotemporally mode-locked fiber lasers undergo nonlinear spatial transformation due to a power-dependent consistent attractor.",
"doi": "10.1038/s42005-023-01185-1",
"issn": "2399-3650",
"publisher": "Nature Publishing Group",
"publication": "Communications Physics",
"publication_date": "2023-04-05",
"volume": "6",
"pages": "Art. No. 60"
},
{
"id": "authors:4vp4e-4f553",
"collection": "authors",
"collection_id": "4vp4e-4f553",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230427-536264000.1",
"type": "article",
"title": "Location-Dependent Spatiotemporal Antialiasing in Photoacoustic Computed Tomography",
"author": [
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic computed tomography (PACT) images optical absorption contrast by detecting ultrasonic waves induced by optical energy deposition in materials such as biological tissues. An ultrasonic transducer array or its scanning equivalent is used to detect ultrasonic waves. The spatial distribution of the transducer elements must satisfy the spatial Nyquist criterion; otherwise, spatial aliasing occurs and causes artifacts in reconstructed images. The spatial Nyquist criterion poses different requirements on the transducer elements' distributions for different locations in the image domain, which has not been studied previously. In this research, we elaborate on the location dependency through spatiotemporal analysis and propose a location-dependent spatiotemporal antialiasing method. By applying this method to PACT in full-ring array geometry, we effectively mitigate aliasing artifacts with minimal effects on image resolution in both numerical simulations and in vivo experiments.",
"doi": "10.1109/TMI.2022.3225565",
"pmcid": "PMC10171137",
"issn": "0278-0062",
"publisher": "IEEE",
"publication": "IEEE Transactions on Medical Imaging",
"publication_date": "2023-04",
"series_number": "4",
"volume": "42",
"issue": "4",
"pages": "1210-1224"
},
{
"id": "authors:ww95w-yvp65",
"collection": "authors",
"collection_id": "ww95w-yvp65",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230427-536514000.3",
"type": "article",
"title": "Learning-based super-resolution interpolation for sub-Nyquist sampled laser speckles",
"author": [
{
"family_name": "Li",
"given_name": "Huanhao",
"orcid": "0000-0002-1652-6328",
"clpid": "Li-Huanhao"
},
{
"family_name": "Yu",
"given_name": "Zhipeng",
"orcid": "0000-0002-9866-2672",
"clpid": "Yu-Zhipeng"
},
{
"family_name": "Zhao",
"given_name": "Qi",
"orcid": "0000-0002-8594-6940",
"clpid": "Zhao-Qi"
},
{
"family_name": "Luo",
"given_name": "Yunqi",
"orcid": "0000-0001-5409-1719",
"clpid": "Luo-Yunqi"
},
{
"family_name": "Cheng",
"given_name": "Shengfu",
"orcid": "0000-0003-2757-6264",
"clpid": "Cheng-Shengfu"
},
{
"family_name": "Zhong",
"given_name": "Tianting",
"orcid": "0000-0002-3925-5903",
"clpid": "Zhong-Tianting"
},
{
"family_name": "Woo",
"given_name": "Chi Man",
"orcid": "0000-0003-1653-5029",
"clpid": "Woo-Chi-Man"
},
{
"family_name": "Liu",
"given_name": "Honglin",
"orcid": "0000-0003-2473-9056",
"clpid": "Liu-Honglin"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Zheng",
"given_name": "Yuanjin",
"clpid": "Zheng-Yuanjin"
},
{
"family_name": "Lai",
"given_name": "Puxiang",
"orcid": "0000-0003-4811-2012",
"clpid": "Lai-Puxiang"
}
],
"abstract": "Information retrieval from visually random optical speckle patterns is desired in many scenarios yet considered challenging. It requires accurate understanding or mapping of the multiple scattering process, or reliable capability to reverse or compensate for the scattering-induced phase distortions. In whatever situation, effective resolving and digitization of speckle patterns are necessary. Nevertheless, on some occasions, to increase the acquisition speed and/or signal-to-noise ratio (SNR), speckles captured by cameras are inevitably sampled in the sub-Nyquist domain via pixel binning (one camera pixel contains multiple speckle grains) due to finite size or limited bandwidth of photosensors. Such a down-sampling process is irreversible; it undermines the fine structures of speckle grains and hence the encoded information, preventing successful information extraction. To retrace the lost information, super-resolution interpolation for such sub-Nyquist sampled speckles is needed. In this work, a deep neural network, namely SpkSRNet, is proposed to effectively up sample speckles that are sampled below 1/10 of the Nyquist criterion to well-resolved ones that not only resemble the comprehensive morphology of original speckles (decompose multiple speckle grains from one camera pixel) but also recover the lost complex information (human face in this study) with high fidelity under normal- and low-light conditions, which is impossible with classic interpolation methods. These successful speckle super-resolution interpolation demonstrations are essentially enabled by the strong implicit correlation among speckle grains, which is non-quantifiable but could be discovered by the well-trained network. With further engineering, the proposed learning platform may benefit many scenarios that are physically inaccessible, enabling fast acquisition of speckles with sufficient SNR and opening up new avenues for seeing big and seeing clearly simultaneously in complex scenarios.",
"doi": "10.1364/prj.472512",
"issn": "2327-9125",
"publisher": "Optica Publishing Group",
"publication": "Photonics Research",
"publication_date": "2023-04",
"series_number": "4",
"volume": "11",
"issue": "4",
"pages": "631-642"
},
{
"id": "authors:hgg5a-fy228",
"collection": "authors",
"collection_id": "hgg5a-fy228",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230215-519459000.1",
"type": "article",
"title": "High-gain and high-speed wavefront shaping through scattering media",
"author": [
{
"family_name": "Cheng",
"given_name": "Zhongtao",
"orcid": "0000-0002-9862-2873",
"clpid": "Cheng-Zhongtao"
},
{
"family_name": "Li",
"given_name": "Chengmingyue",
"orcid": "0000-0001-7609-1314",
"clpid": "Li-Chengmingyue"
},
{
"family_name": "Khadria",
"given_name": "Anjul",
"orcid": "0000-0002-9771-3650",
"clpid": "Khadria-Anjul"
},
{
"family_name": "Zhang",
"given_name": "Yide",
"orcid": "0000-0002-9463-3970",
"clpid": "Zhang-Yide"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Wavefront shaping (WFS) is emerging as a promising tool for controlling and focusing light in complex scattering media. The shaping system's speed, the energy gain of the corrected wavefronts and the control degrees of freedom are the most important metrics for WFS, especially for highly scattering and dynamic samples. Despite recent advances, current methods suffer from trade-offs that limit satisfactory performance to only one or two of these metrics. Here we report a WFS technique that simultaneously achieves high speed, high energy gain and high control degrees of freedom. By combining photorefractive crystal-based analogue optical phase conjugation and stimulated emission light amplification, our technique achieves an energy gain approaching unity; that is, more than three orders of magnitude larger than conventional analogue optical phase conjugation. The response time of ~10\u2009\u03bcs with about 106 control modes corresponds to an average mode time of about 0.01\u2009ns per mode, which is more than 50 times quicker than some of the fastest WFS systems so far. We anticipate that this technique will be instrumental in overcoming the optical diffusion limit in photonics and translate WFS techniques to real-world applications.",
"doi": "10.1038/s41566-022-01142-4",
"pmcid": "PMC10275582",
"issn": "1749-4885",
"publisher": "Nature Publishing Group",
"publication": "Nature Photonics",
"publication_date": "2023-04",
"series_number": "4",
"volume": "17",
"issue": "4",
"pages": "299-305"
},
{
"id": "authors:c8sb6-0p776",
"collection": "authors",
"collection_id": "c8sb6-0p776",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230615-812810000.13",
"type": "article",
"title": "Single-shot photoacoustic imaging with single-element transducer through a spatiotemporal encoder",
"author": [
{
"family_name": "Zhao",
"given_name": "Yanyu",
"clpid": "Zhao-Yanyu"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Significance. Current photoacoustic (PA) imaging modalities typically require either serial detection with a single-element transducer or parallel detections with an ultrasonic array, indicating a dilemma between system cost and imaging throughput. PA topography through ergodic relay (PATER) was recently developed to address this bottleneck. However, PATER requires object-specific calibration due to varied boundary condition and must be recalibrated through pointwise scanning for each object before measurements, which is time-consuming and severely limits practical application. \n\nAim. We aim to develop a new single-shot PA imaging technique that only requires a one-time calibration for imaging different objects using a single-element transducer. \n\nApproach. We develop an imaging method, PA imaging through a spatiotemporal encoder (PAISE), to address the above issue. The spatial information is effectively coded into unique temporal features by the spatiotemporal encoder, which allows for compressive image reconstruction. An ultrasonic waveguide is proposed as a critical element to guide the PA waves from the object into the prism, which effectively accounts for the varied boundary condition of different objects. We further add irregular-shaped edges on the prism to introduce randomized internal reflections and further facilitate the scrambling of acoustic waves. \n\nResults. The proposed technique is validated through comprehensive numerical simulations and experiments, and it is demonstrated that PAISE can successfully overcome the changed boundary condition and can image different samples given a single calibration. \n\nConclusions. The proposed PAISE technique is capable of single-shot widefield PA imaging with a single-element transducer and does not require sample-specific calibration, which successfully overcomes the major limitation of previous PATER technology.",
"doi": "10.1117/1.jbo.28.4.046004",
"pmcid": "PMC10098145",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2023-04",
"series_number": "4",
"volume": "28",
"issue": "4",
"pages": "Art. No. 046004"
},
{
"id": "authors:136hz-aqg78",
"collection": "authors",
"collection_id": "136hz-aqg78",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230427-536553000.6",
"type": "article",
"title": "Path sampling and integration method to calculate speckle patterns",
"author": [
{
"family_name": "Song",
"given_name": "Chunyuan",
"clpid": "Song-Chunyuan"
},
{
"family_name": "Gao",
"given_name": "Jingjing",
"clpid": "Gao-Jingjing"
},
{
"family_name": "Gan",
"given_name": "Yu",
"clpid": "Gan-Yu"
},
{
"family_name": "Zhang",
"given_name": "Xuyu",
"clpid": "Zhang-Xuyu"
},
{
"family_name": "Han",
"given_name": "Shensheng",
"orcid": "0000-0003-1689-5876",
"clpid": "Han-Shensheng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Liu",
"given_name": "Honglin",
"orcid": "0000-0003-2473-9056",
"clpid": "Liu-Honglin"
}
],
"abstract": "A stable speckle pattern is generated when a coherent beam illuminates a stationary scattering medium that contains numerous scatterers with fixed positions. To date, there has been no valid method to the best of our knowledge for calculating the speckle pattern of a macro medium with a large number of scatterers. Here, a new method based on possible path sampling with corresponding weights and coherent superposition is presented for the simulation of optical field propagation in a scattering medium and output speckle patterns. In this method, a photon is launched onto a medium with fixed scatterers. It propagates in one direction; upon collision with a scatterer, its direction is updated. The procedure is repeated until it exits the medium. A sampled path is obtained in this manner. By repeatedly launching photons, numerous independent optical paths can be sampled. A speckle pattern, corresponding to the probability density of the photon, is formed by the coherent superposition of sufficiently sampled path lengths ending on a receiving screen. This method can be used in sophisticated studies of the influences of medium parameters, motion of scatterers, sample distortions on speckle distributions, and morphological appearances. It can be used for micro-examination of optical fields in scattering media and may inspire new methods and techniques for non-invasive precision detection and diagnosis of scattering media.",
"doi": "10.1364/oe.485680",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "2023-03-13",
"series_number": "6",
"volume": "31",
"issue": "6",
"pages": "10458-10472"
},
{
"id": "authors:v3s4y-y9t80",
"collection": "authors",
"collection_id": "v3s4y-y9t80",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230427-536549000.5",
"type": "article",
"title": "Experimental Full-Domain Mapping of Quantum Correlation in Clauser-Horne-Shimony-Holt Scenarios",
"author": [
{
"family_name": "Tong",
"given_name": "Xin",
"orcid": "0000-0003-2002-5638",
"clpid": "Tong-Xin"
},
{
"family_name": "He",
"given_name": "Zhe",
"orcid": "0000-0002-8525-3650",
"clpid": "He-Zhe"
},
{
"family_name": "Zhang",
"given_name": "Yide",
"orcid": "0000-0002-9463-3970",
"clpid": "Zhang-Yide"
},
{
"family_name": "Solomon",
"given_name": "Samuel",
"orcid": "0000-0001-7199-6659",
"clpid": "Solomon-Samuel-A"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Song",
"given_name": "Qiyuan",
"orcid": "0000-0003-4260-4956",
"clpid": "Song-Qiyuan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Quantum correlation between two parties serves as a useful resource in the surging applications of quantum information. The Bell nonlocality and quantum steering have been proposed to describe nonclassical correlations against local-hidden-variable and local-hidden-state theories, respectively. To characterize the two types of nonclassical correlations, various nonlocality and steering inequalities have been established, and the amount of inequality violation serves as a helpful indicator for many entanglement-based tasks. Quantum state tomography has been employed for measuring quantum states, while the method requires intensive computation and does not directly verify either nonlocality or steering over the full domain independent of established theories. Here, we experimentally map the full-domain correlation with bipartite states for nonlocality and quantum steering in Clauser-Horne-Shimony-Holt scenarios. The measurement of the maps automatically accounts for detection imperfections. Furthermore, we demonstrate the application of the correlation maps in the entanglement-based quantum key distribution protocol with arbitrary bipartite states. The correlation maps show direct measurements and simple interpretations that can answer fundamental questions about nonlocality and quantum steering as well as contribute to quantum information applications in a straightforward manner.",
"doi": "10.1103/physrevapplied.19.034049",
"pmcid": "PMC10798678",
"issn": "2331-7019",
"publisher": "American Physical Society",
"publication": "Physical Review Applied",
"publication_date": "2023-03",
"series_number": "3",
"volume": "19",
"issue": "3",
"pages": "034049"
},
{
"id": "authors:6048w-afg35",
"collection": "authors",
"collection_id": "6048w-afg35",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230314-845495900.55",
"type": "article",
"title": "Single-pulse real-time billion-frames-per-second planar imaging of ultrafast nanoparticle-laser dynamics and temperature in flames",
"author": [
{
"family_name": "Mishra",
"given_name": "Yogeshwar Nath",
"orcid": "0000-0003-2063-2200",
"clpid": "Mishra-Yogeshwar-Nath"
},
{
"family_name": "Wang",
"given_name": "Peng",
"orcid": "0000-0002-6302-8495",
"clpid": "Wang-Peng-MEDENG"
},
{
"family_name": "Bauer",
"given_name": "Florian J.",
"clpid": "Bauer-Florian-J"
},
{
"family_name": "Zhang",
"given_name": "Yide",
"orcid": "0000-0002-9463-3970",
"clpid": "Zhang-Yide"
},
{
"family_name": "Hanstorp",
"given_name": "Dag",
"orcid": "0000-0001-6490-6897",
"clpid": "Hanstorp-Dag"
},
{
"family_name": "Will",
"given_name": "Stefan",
"orcid": "0000-0002-1226-0075",
"clpid": "Will-Stefan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Unburnt hydrocarbon flames produce soot, which is the second biggest contributor to global warming and harmful to human health. The state-of-the-art high-speed imaging techniques, developed to study non-repeatable turbulent flames, are limited to million-frames-per-second imaging rates, falling short in capturing the dynamics of critical species. Unfortunately, these techniques do not provide a complete picture of flame-laser interactions, important for understanding soot formation. Furthermore, thermal effects induced by multiple consecutive pulses modify the optical properties of soot nanoparticles, thus making single-pulse imaging essential. Here, we report single-shot laser-sheet compressed ultrafast photography (LS-CUP) for billion-frames-per-second planar imaging of flame-laser dynamics. We observed laser-induced incandescence, elastic light scattering, and fluorescence of soot precursors - polycyclic aromatic hydrocarbons (PAHs) in real-time using a single nanosecond laser pulse. The spatiotemporal maps of the PAHs emission, soot temperature, primary nanoparticle size, soot aggregate size, and the number of monomers, present strong experimental evidence in support of the theory and modeling of soot inception and growth mechanism in flames. LS-CUP represents a generic and indispensable tool that combines a portfolio of ultrafast combustion diagnostic techniques, covering the entire lifecycle of soot nanoparticles, for probing extremely short-lived (picoseconds to nanoseconds) species in the spatiotemporal domain in non-repeatable turbulent environments. Finally, LS-CUP's unparalleled capability of ultrafast wide-field temperature imaging in real-time is envisioned to unravel mysteries in modern physics such as hot plasma, sonoluminescence, and nuclear fusion.",
"doi": "10.1038/s41377-023-01095-5",
"pmcid": "PMC9941513",
"issn": "2047-7538",
"publisher": "Nature Publishing Group",
"publication": "Light: Science & Applications",
"publication_date": "2023-02-21",
"volume": "12",
"pages": "Art. No. 47"
},
{
"id": "authors:178yq-5v957",
"collection": "authors",
"collection_id": "178yq-5v957",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221003-756400000.12",
"type": "article",
"title": "Label-free intraoperative histology of bone tissue via deep-learning-assisted ultraviolet photoacoustic microscopy",
"author": [
{
"family_name": "Cao",
"given_name": "Rui",
"orcid": "0000-0003-4444-7528",
"clpid": "Cao-Rui"
},
{
"family_name": "Nelson",
"given_name": "Scott D.",
"clpid": "Nelson-Scott-D"
},
{
"family_name": "Davis",
"given_name": "Samuel",
"orcid": "0000-0002-0871-8880",
"clpid": "Davis-Samuel"
},
{
"family_name": "Liang",
"given_name": "Yu",
"clpid": "Liang-Yu"
},
{
"family_name": "Luo",
"given_name": "Yilin",
"orcid": "0000-0002-4611-3049",
"clpid": "Luo-Yilin"
},
{
"family_name": "Zhang",
"given_name": "Yide",
"orcid": "0000-0002-9463-3970",
"clpid": "Zhang-Yide"
},
{
"family_name": "Crawford",
"given_name": "Brooke",
"orcid": "0000-0003-2722-7080",
"clpid": "Crawford-Brooke"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Obtaining frozen sections of bone tissue for intraoperative examination is challenging. To identify the bony edge of resection, orthopaedic oncologists therefore rely on pre-operative X-ray computed tomography or magnetic resonance imaging. However, these techniques do not allow for accurate diagnosis or for intraoperative confirmation of the tumour margins, and in bony sarcomas, they can lead to bone margins up to 10-fold wider (1,000-fold volumetrically) than necessary. Here, we show that real-time three-dimensional contour-scanning of tissue via ultraviolet photoacoustic microscopy in reflection mode can be used to intraoperatively evaluate undecalcified and decalcified thick bone specimens, without the need for tissue sectioning. We validate the technique with gold-standard haematoxylin-and-eosin histology images acquired via a traditional optical microscope, and also show that an unsupervised generative adversarial network can virtually stain the ultraviolet-photoacoustic-microscopy images, allowing pathologists to readily identify cancerous features. Label-free and slide-free histology via ultraviolet photoacoustic microscopy may allow for rapid diagnoses of bone-tissue pathologies and aid the intraoperative determination of tumour margins.",
"doi": "10.1038/s41551-022-00940-z",
"pmcid": "PMC10321243",
"issn": "2157-846X",
"publisher": "Nature Publishing Group",
"publication": "Nature Biomedical Engineering",
"publication_date": "2023-02",
"series_number": "2",
"volume": "7",
"issue": "2",
"pages": "124-134"
},
{
"id": "authors:vy85a-9ks10",
"collection": "authors",
"collection_id": "vy85a-9ks10",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221205-666301600.26",
"type": "article",
"title": "Non-Invasive 3D Photoacoustic Tomography of Angiographic Anatomy and Hemodynamics of Fatty Livers in Rats",
"author": [
{
"family_name": "Tong",
"given_name": "Xin",
"clpid": "Tong-Xin"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Cao",
"given_name": "Rui",
"orcid": "0000-0003-4444-7528",
"clpid": "Cao-Rui"
},
{
"family_name": "Zhang",
"given_name": "Yang",
"orcid": "0000-0002-4168-9225",
"clpid": "Zhang-Yang"
},
{
"family_name": "Olick-Gibson",
"given_name": "Joshua",
"clpid": "Olick-Gibson-Joshua"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Non-alcoholic fatty liver disease is the most common liver disorder worldwide, which strongly correlates to obesity, diabetes, and metabolic syndromes. Complementary to mainstream liver diagnostic modalities, photoacoustic tomography (PAT) can provide high-speed images with functional optical contrast. However, PAT has not been demonstrated to study fatty liver anatomy with clear volumetric vasculatures. The livers of multiple rats are non-invasively imaged in vivo using the recently developed 3D PAT platform. The system provides isotropically high spatial resolution in 3D space, presenting clear angiographic structures of rat livers without injecting contrast agents. Furthermore, to quantitatively analyze the difference between the livers of lean and obese rats, the authors measured several PAT features and statistical differences between the two groups are observed. In addition to the anatomy, a time-gated strategy is applied to correct respiration-induced motion artifacts and extracted the hemodynamics of major blood vessels during the breathing cycles. This study demonstrates the capabilities of 3D-PAT to reveal both angiographic anatomy and function in rat livers, providing hematogenous information for fatty liver diagnosis. 3D-PAT, as a new tool for preclinical research, warrants further improvements to be transferred to human pediatric liver imaging.",
"doi": "10.1002/advs.202205759",
"pmcid": "PMC9839842",
"issn": "2198-3844",
"publisher": "Wiley",
"publication": "Advanced Science",
"publication_date": "2023-01-13",
"series_number": "2",
"volume": "10",
"issue": "2",
"pages": "Art. No. 2205759"
},
{
"id": "authors:1swh9-m9e66",
"collection": "authors",
"collection_id": "1swh9-m9e66",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230314-845495900.37",
"type": "article",
"title": "Non-invasive photoacoustic computed tomography of rat heart anatomy and function",
"author": [
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Tong",
"given_name": "Xin",
"orcid": "0000-0003-2002-5638",
"clpid": "Tong-Xin"
},
{
"family_name": "Cavallero",
"given_name": "Susana",
"orcid": "0000-0001-5402-8840",
"clpid": "Cavallero-Susana"
},
{
"family_name": "Zhang",
"given_name": "Yide",
"orcid": "0000-0002-9463-3970",
"clpid": "Zhang-Yide"
},
{
"family_name": "Na",
"given_name": "Shuai",
"orcid": "0000-0003-2083-0047",
"clpid": "Na-Shuai"
},
{
"family_name": "Cao",
"given_name": "Rui",
"orcid": "0000-0003-4444-7528",
"clpid": "Cao-Rui"
},
{
"family_name": "Hsiai",
"given_name": "Tzung K.",
"orcid": "0000-0003-1734-0792",
"clpid": "Hsiai-Tzung-K"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Complementary to mainstream cardiac imaging modalities for preclinical research, photoacoustic computed tomography (PACT) can provide functional optical contrast with high imaging speed and resolution. However, PACT has not been demonstrated to reveal the dynamics of whole cardiac anatomy or vascular system without surgical procedure (thoracotomy) for tissue penetration. Here, we achieved non-invasive imaging of rat hearts using the recently developed three-dimensional PACT (3D-PACT) platform, demonstrating the regulated illumination and detection schemes to reduce the effects of optical attenuation and acoustic distortion through the chest wall; thereby, enabling unimpeded visualization of the cardiac anatomy and intracardiac hemodynamics following rapidly scanning the heart within 10\u2009s. We further applied 3D-PACT to reveal distinct cardiac structural and functional changes among the healthy, hypertensive, and obese rats, with optical contrast to uncover differences in cardiac chamber size, wall thickness, and hemodynamics. Accordingly, 3D-PACT provides high imaging speed and nonionizing penetration to capture the whole heart for diagnosing the animal models, holding promises for clinical translation to cardiac imaging of human neonates.",
"doi": "10.1038/s41377-022-01053-7",
"pmcid": "PMC9807634",
"issn": "2047-7538",
"publisher": "Nature Publishing Group",
"publication": "Light: Science & Applications",
"publication_date": "2023-01-03",
"volume": "12",
"pages": "Art. No. 12"
},
{
"id": "authors:nge82-az964",
"collection": "authors",
"collection_id": "nge82-az964",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230125-514949300.27",
"type": "article",
"title": "Optical-resolution photoacoustic microscopy with a needle-shaped beam",
"author": [
{
"family_name": "Cao",
"given_name": "Rui",
"orcid": "0000-0003-4444-7528",
"clpid": "Cao-Rui"
},
{
"family_name": "Zhao",
"given_name": "Jingjing",
"clpid": "Zhao-Jingjing"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Du",
"given_name": "Lin",
"orcid": "0000-0002-6111-4947",
"clpid": "Du-Lin"
},
{
"family_name": "Zhang",
"given_name": "Yide",
"orcid": "0000-0002-9463-3970",
"clpid": "Zhang-Yide"
},
{
"family_name": "Luo",
"given_name": "Yilin",
"orcid": "0000-0002-4611-3049",
"clpid": "Luo-Yilin"
},
{
"family_name": "Jiang",
"given_name": "Laiming",
"orcid": "0000-0002-8658-3168",
"clpid": "Jiang-Laiming"
},
{
"family_name": "Davis",
"given_name": "Samuel",
"orcid": "0000-0002-0871-8880",
"clpid": "Davis-Samuel"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"orcid": "0000-0003-1527-3020",
"clpid": "Zhou-Qifa"
},
{
"family_name": "de la Zerda",
"given_name": "Adam",
"orcid": "0000-0002-5617-0194",
"clpid": "de-la-Zerda-Adam"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical-resolution photoacoustic microscopy can visualize wavelength-dependent optical absorption at the cellular level. However, this technique suffers from a limited depth of field due to the tight focus of the optical excitation beam, making it challenging to acquire high-resolution images of samples with uneven surfaces or high-quality volumetric images without z scanning. To overcome this limitation, we propose needle-shaped beam photoacoustic microscopy, which can extend the depth of field to around a 28-fold Rayleigh length via customized diffractive optical elements. These diffractive optical elements generate a needle-shaped beam with a well-maintained beam diameter, a uniform axial intensity distribution and negligible sidelobes. The advantage of using needle-shaped beam photoacoustic microscopy is demonstrated via both histology-like imaging of fresh slide-free organs using a 266\u2009nm laser and in vivo mouse-brain vasculature imaging using a 532\u2009nm laser. This approach provides new perspectives for slide-free intraoperative pathological imaging and in vivo organ-level imaging.",
"doi": "10.1038/s41566-022-01112-w",
"issn": "1749-4885",
"publisher": "Nature Publishing Group",
"publication": "Nature Photonics",
"publication_date": "2023-01",
"series_number": "1",
"volume": "17",
"issue": "1",
"pages": "89-95"
},
{
"id": "authors:en83e-65f62",
"collection": "authors",
"collection_id": "en83e-65f62",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230227-88449200.47",
"type": "article",
"title": "Introduction to the special issue on celebrating the 15th anniversary of JIOHS and the 70th anniversary of HUST",
"author": [
{
"family_name": "Luo",
"given_name": "Qingming",
"orcid": "0000-0002-6725-9311",
"clpid": "Luo-Qingming"
},
{
"family_name": "Tuchin",
"given_name": "Valery V.",
"orcid": "0000-0001-7479-2694",
"clpid": "Tuchin-Valery-V"
},
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Since launching in 2008, Journal of Innovative Optical Health Sciences (JIOHS) has been published for 15 years until 2022. Supported by the founding advisor Prof. Britton Chance and other founding Editorial Members, JIOHS was quickly embraced by the biomedical optics community, especially in Asia. Authors submitted some of their high quality papers to JIOHS, which led to a constant Impact Factor (IF) increase from the first IF 0.632 to IF 2.396 (Journal Citation Report 2021). JIOHS is now one of the most important journals in the field of biomedical optics and biophotonics. The year 2022 is the 15th Anniversary of JIOHS and also the 70th Anniversary of Huazhong University of Science & Technology (HUST). Naturally, organizing a special issue is certainly the most important way to celebrate these two anniversaries. A brief history of the development of biophotonics and biomedical optics at HUST, associated with the formation of the journal and the development of international relations, including through the regular organization of the international conference PIBM and the Chinese-Russian Workshops, is presented in the photos. This special issue on Celebrating the 15th Anniversary of JIOHS and the 70th Anniversary of HUST consists of eight invited and two regular articles. Among them, nine articles are published in January 2023 issue, while the paper from Wei R Chen will be available in the next issue. All these articles are dedicated to highlighting the latest developments in the fields of biomedical optics and biophotonics.",
"doi": "10.1142/s1793545823020017",
"issn": "1793-5458",
"publisher": "World Scientific",
"publication": "Journal of Innovative Optical Health Sciences",
"publication_date": "2023-01",
"series_number": "1",
"volume": "16",
"issue": "1",
"pages": "Art. No. 2302001"
},
{
"id": "authors:ak346-wkp54",
"collection": "authors",
"collection_id": "ak346-wkp54",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220825-833128900.761",
"type": "article",
"title": "Long-Duration and Non-Invasive Photoacoustic Imaging of Multiple Anatomical Structures in a Live Mouse Using a Single Contrast Agent",
"author": [
{
"family_name": "Khadria",
"given_name": "Anjul",
"orcid": "0000-0002-9771-3650",
"clpid": "Khadria-Anjul"
},
{
"family_name": "Paavola",
"given_name": "Chad D.",
"orcid": "0000-0001-6952-1400",
"clpid": "Paavola-Chad-D"
},
{
"family_name": "Zhang",
"given_name": "Yang",
"orcid": "0000-0002-4168-9225",
"clpid": "Zhang-Yang"
},
{
"family_name": "Davis",
"given_name": "Samuel P. X.",
"clpid": "Davis-Samuel-P-X"
},
{
"family_name": "Grealish",
"given_name": "Patrick F.",
"clpid": "Grealish-Patrick-F"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-Konstantin-I"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Beals",
"given_name": "John M.",
"clpid": "Beals-John-M"
},
{
"family_name": "Oladipupo",
"given_name": "Sunday S.",
"orcid": "0000-0001-6555-0693",
"clpid": "Oladipupo-Sunday-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Long-duration in vivo simultaneous imaging of multiple anatomical structures is useful for understanding physiological aspects of diseases, informative for molecular optimization in preclinical models, and has potential applications in surgical settings to improve clinical outcomes. Previous studies involving simultaneous imaging of multiple anatomical structures, for example, blood and lymphatic vessels as well as peripheral nerves and sebaceous glands, have used genetically engineered mice, which require expensive and time-consuming methods. Here, an IgG4 isotype control antibody is labeled with a near-infrared dye and injected into a mouse ear to enable simultaneous visualization of blood and lymphatic vessels, peripheral nerves, and sebaceous glands for up to 3 h using photoacoustic microscopy. For multiple anatomical structure imaging, peripheral nerves and sebaceous glands are imaged inside the injected dye-labeled antibody mass while the lymphatic vessels are visualized outside the mass. The efficacy of the contrast agent to label and localize deep medial lymphatic vessels and lymph nodes using photoacoustic computed tomography is demonstrated. The capability of a single injectable contrast agent to image multiple structures for several hours will potentially improve preclinical therapeutic optimization, shorten discovery timelines, and enable clinical treatments.",
"doi": "10.1002/advs.202202907",
"pmcid": "PMC9534965",
"issn": "2198-3844",
"publisher": "Wiley",
"publication": "Advanced Science",
"publication_date": "2022-10-05",
"series_number": "28",
"volume": "9",
"issue": "28",
"pages": "2202907"
},
{
"id": "authors:qyzb2-abw73",
"collection": "authors",
"collection_id": "qyzb2-abw73",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220715-744287000",
"type": "article",
"title": "Roadmap on wavefront shaping and deep imaging in complex media",
"author": [
{
"family_name": "Gigan",
"given_name": "Sylvain",
"orcid": "0000-0002-9914-6231",
"clpid": "Gigan-Sylvain"
},
{
"family_name": "Katz",
"given_name": "Ori",
"clpid": "Katz-Ori"
},
{
"family_name": "de Aguiar",
"given_name": "Hilton B.",
"orcid": "0000-0002-2426-0371",
"clpid": "de-Aguiar-Hilton-B"
},
{
"family_name": "Andresen",
"given_name": "Esben Ravn",
"clpid": "Andresen-Esben-Ravn"
},
{
"family_name": "Aubry",
"given_name": "Alexandre",
"clpid": "Aubry-Alexandre"
},
{
"family_name": "Bertolotti",
"given_name": "Jacopo",
"clpid": "Bertolotti-Jacopo"
},
{
"family_name": "Bossy",
"given_name": "Emmanuel",
"orcid": "0000-0002-8101-8290",
"clpid": "Bossy-Emmanuel"
},
{
"family_name": "Bouchet",
"given_name": "Dorian",
"orcid": "0000-0002-9122-5170",
"clpid": "Bouchet-Dorian"
},
{
"family_name": "Brake",
"given_name": "Joshua",
"orcid": "0000-0002-5113-6886",
"clpid": "Brake-Joshua-H"
},
{
"family_name": "Brasselet",
"given_name": "Sophie",
"clpid": "Brasselet-Sophie"
},
{
"family_name": "Bromberg",
"given_name": "Yaron",
"clpid": "Bromberg-Yaron"
},
{
"family_name": "Cao",
"given_name": "Hui",
"orcid": "0000-0002-5339-6892",
"clpid": "Cao-Hui"
},
{
"family_name": "Chaigne",
"given_name": "Thomas",
"clpid": "Chaigne-Thomas"
},
{
"family_name": "Cheng",
"given_name": "Zhongtao",
"orcid": "0000-0002-9862-2873",
"clpid": "Cheng-Zhongtao"
},
{
"family_name": "Choi",
"given_name": "Wonshik",
"clpid": "Choi-Wonshik"
},
{
"family_name": "Ci\u017em\u00e1r",
"given_name": "Tom\u00e1\u0161",
"clpid": "Ci\u017em\u00e1r-Tom\u00e1\u0161"
},
{
"family_name": "Cui",
"given_name": "Meng",
"clpid": "Cui-Meng"
},
{
"family_name": "Curtis",
"given_name": "Vincent R.",
"clpid": "Curtis-Vincent-R"
},
{
"family_name": "Defienne",
"given_name": "Hugo",
"orcid": "0000-0002-5543-2885",
"clpid": "Defienne-Hugo"
},
{
"family_name": "Hofer",
"given_name": "Matthias",
"clpid": "Hofer-Matthias"
},
{
"family_name": "Horisaki",
"given_name": "Ryoichi",
"clpid": "Horisaki-Ryoichi"
},
{
"family_name": "Horstmeyer",
"given_name": "Roarke",
"orcid": "0000-0002-2480-9141",
"clpid": "Horstmeyer-Roarke"
},
{
"family_name": "Ji",
"given_name": "Na",
"clpid": "Ji-Na"
},
{
"family_name": "LaViolette",
"given_name": "Aaron K.",
"clpid": "LaViolette-Aaron-K"
},
{
"family_name": "Mertz",
"given_name": "Jerome",
"clpid": "Mertz-Jerome"
},
{
"family_name": "Moser",
"given_name": "Christophe",
"clpid": "Moser-Christophe"
},
{
"family_name": "Mosk",
"given_name": "Allard P.",
"orcid": "0000-0002-1140-6626",
"clpid": "Mosk-Allard-P"
},
{
"family_name": "P\u00e9gard",
"given_name": "Nicolas C.",
"clpid": "P\u00e9gard-Nicolas-C"
},
{
"family_name": "Piestun",
"given_name": "Rafael",
"clpid": "Piestun-Rafael"
},
{
"family_name": "Popoff",
"given_name": "S\u00e9bastien",
"clpid": "Popoff-S\u00e9bastien"
},
{
"family_name": "Phillips",
"given_name": "David B.",
"clpid": "Phillips-David-B"
},
{
"family_name": "Psaltis",
"given_name": "Demetri",
"clpid": "Psaltis-Demetri"
},
{
"family_name": "Rahmani",
"given_name": "Babak",
"clpid": "Rahmani-Babak"
},
{
"family_name": "Rigneault",
"given_name": "Herv\u00e9",
"clpid": "Rigneault-Herv\u00e9"
},
{
"family_name": "Rotter",
"given_name": "Stefan",
"orcid": "0000-0002-4123-1417",
"clpid": "Rotter-Stefan"
},
{
"family_name": "Tian",
"given_name": "Lei",
"orcid": "0000-0002-1316-4456",
"clpid": "Tian-Lei"
},
{
"family_name": "Vellekoop",
"given_name": "Ivo M.",
"clpid": "Vellekoop-Ivo-M"
},
{
"family_name": "Waller",
"given_name": "Laura",
"clpid": "Waller-Laura"
},
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Weber",
"given_name": "Timothy",
"clpid": "Weber-Timothy"
},
{
"family_name": "Xiao",
"given_name": "Sheng",
"clpid": "Xiao-Sheng"
},
{
"family_name": "Xu",
"given_name": "Chris",
"orcid": "0000-0002-3493-6427",
"clpid": "Xu-Chris"
},
{
"family_name": "Yamilov",
"given_name": "Alexey",
"orcid": "0000-0002-9339-6475",
"clpid": "Yamilov-Alexey"
},
{
"family_name": "Yang",
"given_name": "Changhuei",
"orcid": "0000-0001-8791-0354",
"clpid": "Yang-Changhuei"
},
{
"family_name": "Yilmaz",
"given_name": "Hasan",
"orcid": "0000-0003-1889-3516",
"clpid": "Yilmaz-Hasan"
}
],
"abstract": "The last decade has seen the development of a wide set of tools, such as wavefront shaping, computational or fundamental methods, that allow us to understand and control light propagation in a complex medium, such as biological tissues or multimode fibers. A vibrant and diverse community is now working in this field, which has revolutionized the prospect of diffraction-limited imaging at depth in tissues. This roadmap highlights several key aspects of this fast developing field, and some of the challenges and opportunities ahead.",
"doi": "10.1088/2515-7647/ac76f9",
"issn": "2515-7647",
"publisher": "IOP Publishing",
"publication": "Journal of Physics: Photonics",
"publication_date": "2022-10",
"series_number": "4",
"volume": "4",
"issue": "4",
"pages": "Art. No. 042501"
},
{
"id": "authors:nx4k5-wzb27",
"collection": "authors",
"collection_id": "nx4k5-wzb27",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220919-371211400",
"type": "article",
"title": "Ultrafast and hypersensitive phase imaging of propagating internodal current flows in myelinated axons and electromagnetic pulses in dielectrics",
"author": [
{
"family_name": "Zhang",
"given_name": "Yide",
"orcid": "0000-0002-9463-3970",
"clpid": "Zhang-Yide"
},
{
"family_name": "Shen",
"given_name": "Binglin",
"orcid": "0000-0001-9687-9010",
"clpid": "Shen-Binglin"
},
{
"family_name": "Wu",
"given_name": "Tong",
"clpid": "Wu-Tong"
},
{
"family_name": "Zhao",
"given_name": "Jerry",
"clpid": "Zhao-Jerry"
},
{
"family_name": "Jing",
"given_name": "Joseph C.",
"orcid": "0000-0002-1283-3232",
"clpid": "Jing-Joseph-C"
},
{
"family_name": "Wang",
"given_name": "Peng",
"orcid": "0000-0001-8420-5326",
"clpid": "Wang-Peng"
},
{
"family_name": "Sasaki-Capela",
"given_name": "Kanomi",
"clpid": "Sasaki-Capela-Kanomi"
},
{
"family_name": "Dunphy",
"given_name": "William G.",
"orcid": "0000-0001-7598-8939",
"clpid": "Dunphy-W-G"
},
{
"family_name": "Garrett",
"given_name": "David",
"orcid": "0000-0002-9747-8494",
"clpid": "Garrett-David-C"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Weiwei",
"clpid": "Wang-Weiwei"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Many ultrafast phenomena in biology and physics are fundamental to our scientific understanding but have not yet been visualized owing to the extreme speed and sensitivity requirements in imaging modalities. Two examples are the propagation of passive current flows through myelinated axons and electromagnetic pulses through dielectrics, which are both key to information processing in living organisms and electronic devices. Here, we demonstrate differentially enhanced compressed ultrafast photography (Diff-CUP) to directly visualize propagations of passive current flows at approximately 100\u2009m/s along internodes, i.e., continuous myelinated axons between nodes of Ranvier, from Xenopus laevis sciatic nerves and of electromagnetic pulses at approximately 5\u2009\u00d7\u200910\u2077\u2009m/s through lithium niobate. The spatiotemporal dynamics of both propagation processes are consistent with the results from computational models, demonstrating that Diff-CUP can span these two extreme timescales while maintaining high phase sensitivity. With its ultrahigh speed (picosecond resolution), high sensitivity, and noninvasiveness, Diff-CUP provides a powerful tool for investigating ultrafast biological and physical phenomena.",
"doi": "10.1038/s41467-022-33002-8",
"pmcid": "PMC9448739",
"issn": "2041-1723",
"publisher": "Nature Publishing Group",
"publication": "Nature Communications",
"publication_date": "2022-09-06",
"volume": "13",
"pages": "Art. No. 5247"
},
{
"id": "authors:pt6wf-t2493",
"collection": "authors",
"collection_id": "pt6wf-t2493",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220714-369420000",
"type": "article",
"title": "Cross\u2010Ray Ultrasound Tomography and Photoacoustic Tomography of Cerebral Hemodynamics in Rodents",
"author": [
{
"family_name": "Na",
"given_name": "Shuai",
"orcid": "0000-0003-2083-0047",
"clpid": "Na-Shuai"
},
{
"family_name": "Zhang",
"given_name": "Yang",
"orcid": "0000-0002-4168-9225",
"clpid": "Zhang-Yang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Recent advances in functional ultrasound imaging (fUS) and photoacoustic tomography (PAT) offer powerful tools for studying brain function. Complementing each other, fUS and PAT, respectively, measure the cerebral blood flow (CBF) and hemoglobin concentrations, allowing synergistic characterization of cerebral hemodynamics. Here, cross-ray ultrasound tomography (CRUST) and its combination with PAT are presented. CRUST employs a virtual point source from a spherically focused ultrasonic transducer (SFUST) to provide widefield excitation at a 4-kHz pulse repetition frequency. A full-ring-shaped ultrasonic transducer array whose imaging plane is orthogonal to the SFUST's acoustic axis receives scattered ultrasonic waves. Superior to conventional fUS, whose sensitivity to blood flow is angle-dependent and low for perpendicular flow, the crossed transmission and panoramic detection fields of CRUST provide omnidirectional sensitivity to CBF. Using CRUST-PAT, the CBF, oxygen saturation, and hemoglobin concentration changes of the mouse brain during sensory stimulation are measured, with a field of view of \u22487 mm in diameter, spatial resolution of \u2248170 \u00b5m, and temporal resolution of 200 Hz. The results demonstrate CRUST-PAT as a unique tool for studying cerebral hemodynamics.",
"doi": "10.1002/advs.202201104",
"pmcid": "PMC9443457",
"issn": "2198-3844",
"publisher": "Wiley",
"publication": "Advanced Science",
"publication_date": "2022-09-05",
"series_number": "25",
"volume": "9",
"issue": "25",
"pages": "Art. No. 2201104"
},
{
"id": "authors:bct6d-zg449",
"collection": "authors",
"collection_id": "bct6d-zg449",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220803-224712000",
"type": "article",
"title": "Wavefront shaping: A versatile tool to conquer multiple scattering in multidisciplinary fields",
"author": [
{
"family_name": "Yu",
"given_name": "Zhipeng",
"clpid": "Yu-Zhipeng"
},
{
"family_name": "Li",
"given_name": "Huanhao",
"clpid": "Li-Huanhao"
},
{
"family_name": "Zhong",
"given_name": "Tianting",
"clpid": "Zhao-Tianting"
},
{
"family_name": "Park",
"given_name": "Jung-Hoon",
"clpid": "Park-Jung-Hoon"
},
{
"family_name": "Cheng",
"given_name": "Shengfu",
"clpid": "Cheng-Shengfu"
},
{
"family_name": "Woo",
"given_name": "Chi Man",
"clpid": "Woo-Chi-Man"
},
{
"family_name": "Zhao",
"given_name": "Qi",
"clpid": "Zhao-Qi"
},
{
"family_name": "Yao",
"given_name": "Jing",
"clpid": "Yao-Jing"
},
{
"family_name": "Zhou",
"given_name": "Yingying",
"clpid": "Zhou-Yingying"
},
{
"family_name": "Huang",
"given_name": "Xiazi",
"clpid": "Huang-Xiazi"
},
{
"family_name": "Pang",
"given_name": "Weiran",
"clpid": "Pang-Weiran"
},
{
"family_name": "Yoon",
"given_name": "Hansol",
"clpid": "Yoon-Hansol"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Liu",
"given_name": "Honglin",
"orcid": "0000-0003-2473-9056",
"clpid": "Liu-Honglin"
},
{
"family_name": "Zheng",
"given_name": "Yuanjin",
"clpid": "Zheng-Yuanjin"
},
{
"family_name": "Park",
"given_name": "YongKeun",
"clpid": "Park-YongKeun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Lai",
"given_name": "Puxiang",
"clpid": "Lai-Puxiang"
}
],
"abstract": "Optical techniques offer a wide variety of applications as light-matter interactions provide extremely sensitive mechanisms to probe or treat target media. Most of these implementations rely on the usage of ballistic or quasi-ballistic photons to achieve high spatial resolution. However, the inherent scattering nature of light in biological tissues or tissue-like scattering media constitutes a critical obstacle that has restricted the penetration depth of non-scattered photons and hence limited the implementation of most optical techniques for wider applications. In addition, the components of an optical system are usually designed and manufactured for a fixed function or performance. Recent advances in wavefront shaping have demonstrated that scattering- or component-induced phase distortions can be compensated by optimizing the wavefront of the input light pattern through iteration or by conjugating the transmission matrix of the scattering medium. This offers unprecedented opportunities in many applications to achieve controllable optical delivery or detection at depths, or dynamically configurable functionalities by using scattering media to substitute conventional optical components. In this article, the recent progress of wavefront shaping in multidisciplinary fields is reviewed, from optical focusing and imaging with scattering media, functionalized devices, modulation of mode coupling and nonlinearity in multimode fiber, and to multimode fiber-based applications. Apart from insights into the underlying principles and recent advances in wavefront shaping implementations, practical limitations and roadmap for future development are discussed in depth. Looking back and looking forward, it is believed that wavefront shaping holds a bright future that will open new avenues for noninvasive or minimally invasive optical interactions and arbitrary control inside deep tissues. The high degree of freedom with multiple scattering will also provide unprecedented opportunities to develop novel optical devices based on a single scattering medium (generic or customized) that can outperform traditional optical components.",
"doi": "10.1016/j.xinn.2022.100292",
"pmcid": "PMC9405113",
"issn": "2666-6758",
"publisher": "Cell Press",
"publication": "The Innovation",
"publication_date": "2022-09",
"series_number": "5",
"volume": "3",
"issue": "5",
"pages": "Art. No. 100292"
},
{
"id": "authors:qtvk1-6hr40",
"collection": "authors",
"collection_id": "qtvk1-6hr40",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221017-12147700.17",
"type": "article",
"title": "Multiscale photoacoustic tomography of neural activities with GCaMP calcium indicators",
"author": [
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Li",
"given_name": "Lei S.",
"clpid": "Li-Lei-S"
},
{
"family_name": "Rao",
"given_name": "Bin",
"orcid": "0000-0001-6494-3110",
"clpid": "Rao-Bin"
},
{
"family_name": "Rong",
"given_name": "Haoyang",
"clpid": "Rong-Haoyang"
},
{
"family_name": "Sun",
"given_name": "Min-Yu",
"clpid": "Sun-Min-Yu"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"orcid": "0000-0003-1527-3020",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Mennerick",
"given_name": "Steven",
"orcid": "0000-0003-0868-0664",
"clpid": "Mennerick-Steven"
},
{
"family_name": "Raman",
"given_name": "Baranidharan",
"orcid": "0000-0002-7866-155X",
"clpid": "Raman-Baranidharan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Significance: Optical imaging of responses in fluorescently labeled neurons has progressed significantly in recent years. However, there is still a need to monitor neural activities at divergent spatial scales and at depths beyond the optical diffusion limit.\n\nAim: To meet these needs, we aim to develop multiscale photoacoustic tomography (PAT) to image neural activities across spatial scales with a genetically encoded calcium indicator GCaMP.\n\nApproach: First, using photoacoustic microscopy, we show that depth-resolved GCaMP signals can be monitored in vivo from a fly brain in response to odor stimulation without depth scanning and even with the cuticle intact. In vivo monitoring of GCaMP signals was also demonstrated in mouse brains. Next, using photoacoustic computed tomography, we imaged neural responses of a mouse brain slice at depths beyond the optical diffusion limit.\n\nResults: We provide the first unambiguous demonstration that multiscale PAT can be used to record neural activities in transgenic flies and mice with select neurons expressing GCaMP.\n\nConclusions: Our results indicate that the combination of multiscale PAT and fluorescent neural activity indicators provides a methodology for imaging targeted neurons at various scales.",
"doi": "10.1117/1.jbo.27.9.096004",
"pmcid": "PMC9463545",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2022-09",
"series_number": "9",
"volume": "27",
"issue": "9",
"pages": "Art. No. 096004"
},
{
"id": "authors:cns5w-2m168",
"collection": "authors",
"collection_id": "cns5w-2m168",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230111-282624100.14",
"type": "article",
"title": "A multidisciplinary Prematurity Research Cohort Study",
"author": [
{
"family_name": "Stout",
"given_name": "Molly J.",
"orcid": "0000-0001-5171-313X",
"clpid": "Stout-Molly-J"
},
{
"family_name": "Chubiz",
"given_name": "Jessica",
"clpid": "Chubiz-Jessica"
},
{
"family_name": "Raghuraman",
"given_name": "Nandini",
"orcid": "0000-0003-2747-5113",
"clpid": "Raghuraman-Nandini"
},
{
"family_name": "Zhao",
"given_name": "Peinan",
"orcid": "0000-0002-9716-3441",
"clpid": "Zhao-Peinan"
},
{
"family_name": "Tuuli",
"given_name": "Methodius G.",
"clpid": "Tuuli-Methodius-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Cahill",
"given_name": "Alison G.",
"orcid": "0000-0002-6012-3374",
"clpid": "Cahill-Alison-G"
},
{
"family_name": "Cuculich",
"given_name": "Phillip S.",
"orcid": "0000-0001-8127-2240",
"clpid": "Cuculich-Phillip-S"
},
{
"family_name": "Wang",
"given_name": "Yong",
"clpid": "Wang-Yong"
},
{
"family_name": "Jungheim",
"given_name": "Emily S.",
"orcid": "0000-0003-2893-8773",
"clpid": "Jungheim-Emily-S"
},
{
"family_name": "Herzog",
"given_name": "Erik D.",
"orcid": "0000-0001-7209-5174",
"clpid": "Herzog-Erik-D"
},
{
"family_name": "Fay",
"given_name": "Justin",
"orcid": "0000-0003-1893-877X",
"clpid": "Fay-Justin"
},
{
"family_name": "Schwartz",
"given_name": "Alan L.",
"clpid": "Schwartz-Alan-L"
},
{
"family_name": "Macones",
"given_name": "George A.",
"orcid": "0000-0002-1164-3568",
"clpid": "Macones-George-A"
},
{
"family_name": "England",
"given_name": "Sarah K.",
"orcid": "0000-0003-4247-0281",
"clpid": "England-Sarah-K"
}
],
"abstract": "Background: Worldwide, 10% of babies are born preterm, defined as a live birth before 37 weeks of gestation. Preterm birth is the leading cause of neonatal death, and survivors face lifelong risks of adverse outcomes. New approaches with large sample sizes are needed to identify strategies to predict and prevent preterm birth. The primary aims of the Washington University Prematurity Research Cohort Study were to conduct three prospective projects addressing possible causes of preterm birth and provide data and samples for future research. \n\nStudy design: Pregnant patients were recruited into the cohort between January 2017 and January 2020. Consenting patients were enrolled into the study before 20 weeks' gestation and followed through delivery. Participants completed demographic and lifestyle surveys; provided maternal blood, placenta samples, and cord blood; and participated in up to three projects focused on underlying physiology of preterm birth: cervical imaging (Project 1), circadian rhythms (Project 2), and uterine magnetic resonance imaging and electromyometrial imaging (Project 3). \n\nResults: A total of 1260 participants were enrolled and delivered during the study period. Of the participants, 706 (56%) were Black/African American, 494 (39%) were nulliparous, and 185 (15%) had a previous preterm birth. Of the 1260 participants, 1220 (97%) delivered a live infant. Of the 1220 with a live birth, 163 (14.1%) had preterm birth, of which 74 (6.1%) were spontaneous preterm birth. Of the 1220 participants with a live birth, 841 participated in cervical imaging, 1047 contributed data and/or samples on circadian rhythms, and 39 underwent uterine magnetic resonance imaging. Of the 39, 25 underwent electromyometrial imaging. \n\nConclusion: We demonstrate feasibility of recruiting and retaining a diverse cohort in a complex prospective, longitudinal study throughout pregnancy. The extensive clinical, imaging, survey, and biologic data obtained will be used to explore cervical, uterine, and endocrine physiology of preterm birth and can be used to develop novel approaches to predict and prevent preterm birth.",
"doi": "10.1371/journal.pone.0272155",
"pmcid": "PMC9409532",
"issn": "1932-6203",
"publisher": "Public Library of Science",
"publication": "PLoS ONE",
"publication_date": "2022-08-25",
"series_number": "8",
"volume": "17",
"issue": "8",
"pages": "Art. No. e0272155"
},
{
"id": "authors:4aq8p-5bz15",
"collection": "authors",
"collection_id": "4aq8p-5bz15",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220315-626283000",
"type": "article",
"title": "Photoacoustic imaging reveals mechanisms of rapid-acting insulin formulations dynamics at the injection site",
"author": [
{
"family_name": "Khadria",
"given_name": "Anjul",
"orcid": "0000-0002-9771-3650",
"clpid": "Khadria-Anjul"
},
{
"family_name": "Paavola",
"given_name": "Chad D.",
"orcid": "0000-0001-6952-1400",
"clpid": "Paavola-Chad-D"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-Konstantin-I"
},
{
"family_name": "Valenzuela",
"given_name": "Francisco A.",
"clpid": "Valenzuela-Francisco-A"
},
{
"family_name": "Sperry",
"given_name": "Andrea E.",
"clpid": "Sperry-Andrea-E"
},
{
"family_name": "Cox",
"given_name": "Amy L.",
"clpid": "Cox-Amy-L"
},
{
"family_name": "Cao",
"given_name": "Rui",
"orcid": "0000-0003-4444-7528",
"clpid": "Cao-Rui"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Brown-Augsburger",
"given_name": "Patricia L.",
"clpid": "Brown-Augsburger-Patricia-L"
},
{
"family_name": "Lozano",
"given_name": "Emmanuel",
"clpid": "Lozano-Emmanuel"
},
{
"family_name": "Blankenship",
"given_name": "Ross L.",
"clpid": "Blankenship-Ross-L"
},
{
"family_name": "Majumdar",
"given_name": "Ranajoy",
"clpid": "Majumdar-Ranajoy"
},
{
"family_name": "Bradley",
"given_name": "Scott A.",
"clpid": "Bradley-Scott-A"
},
{
"family_name": "Beals",
"given_name": "John M.",
"clpid": "Beals-John-M"
},
{
"family_name": "Oladipupo",
"given_name": "Sunday S.",
"orcid": "0000-0001-6555-0693",
"clpid": "Oladipupo-Sunday-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Objective: Ultra-rapid insulin formulations control postprandial hyperglycemia; however, inadequate understanding of injection site absorption mechanisms is limiting further advancement. We used photoacoustic imaging to investigate the injection site dynamics of dye-labeled insulin lispro in the Humalog\u00ae and Lyumjev\u00ae formulations using the murine ear cutaneous model and correlated it with results from unlabeled insulin lispro in pig subcutaneous injection model. \n\nMethods: We employed dual-wavelength optical-resolution photoacoustic microscopy to study the absorption and diffusion of the near-infrared dye-labeled insulin lispro in the Humalog and Lyumjev formulations in mouse ears. We mathematically modeled the experimental data to calculate the absorption rate constants and diffusion coefficients. We studied the pharmacokinetics of the unlabeled insulin lispro in both the Humalog and Lyumjev formulations as well as a formulation lacking both the zinc and phenolic preservative in pigs. The association state of insulin lispro in each of the formulations was characterized using SV-AUC and NMR spectroscopy. \n\nResults: Through experiments using murine and swine models, we show that the hexamer dissociation rate of insulin lispro is not the absorption rate-limiting step. We demonstrated that the excipients in the Lyumjev formulation produce local tissue expansion and speed both insulin diffusion and microvascular absorption. We also show that the diffusion of insulin lispro at the injection site drives its initial absorption; however, the rate at which the insulin lispro crosses the blood vessels is its overall absorption rate-limiting step. \n\nConclusions: This study provides insights into injection site dynamics of insulin lispro and the impact of formulation excipients. It also demonstrates photoacoustic microscopy as a promising tool for studying protein therapeutics. The results from this study address critical questions around the subcutaneous behavior of insulin lispro and the formulation excipients, which could be useful to make faster and better controlled insulin formulations in the future.",
"doi": "10.1016/j.molmet.2022.101522",
"pmcid": "PMC9207296",
"issn": "2212-8778",
"publisher": "Elsevier",
"publication": "Molecular Metabolism",
"publication_date": "2022-08",
"volume": "62",
"pages": "Art. No. 101522"
},
{
"id": "authors:8a397-ysm46",
"collection": "authors",
"collection_id": "8a397-ysm46",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220608-849382000",
"type": "article",
"title": "Derivation from Bloch Equation to von Neumann Equation to Schr\u00f6dinger-Pauli Equation",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The transition from classical physics to quantum mechanics has been mysterious. Here, we mathematically derive the space-independent von Neumann equation for electron spin from the classical Bloch equation. Subsequently, the space-independent Schr\u00f6dinger\u2013Pauli equation is derived in both the quantum mechanical and recently developed co-quantum dynamic frameworks.",
"doi": "10.1007/s10701-022-00578-6",
"issn": "0015-9018",
"publisher": "Springer",
"publication": "Foundations of Physics",
"publication_date": "2022-06-06",
"series_number": "3",
"volume": "52",
"issue": "3",
"pages": "Art. No. 61"
},
{
"id": "authors:awv6q-5a189",
"collection": "authors",
"collection_id": "awv6q-5a189",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220324-205710950",
"type": "article",
"title": "The emerging role of photoacoustic imaging in clinical oncology",
"author": [
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Clinical oncology can benefit substantially from imaging technologies that reveal physiological characteristics with multiscale observations. Complementing conventional imaging modalities, photoacoustic imaging (PAI) offers rapid imaging (for example, cross-sectional imaging in real time or whole-breast scanning in 10\u201315\u2009s), scalably high levels of spatial resolution, safe operation and adaptable configurations. Most importantly, this novel imaging modality provides informative optical contrast that reveals details on anatomical, functional, molecular and histological features. In this Review, we describe the current state of development of PAI and the emerging roles of this technology in cancer screening, diagnosis and therapy. We comment on the performance of cutting-edge photoacoustic platforms, and discuss their clinical applications and utility in various clinical studies. Notably, the clinical translation of PAI is accelerating in the areas of macroscopic and mesoscopic imaging for patients with breast or skin cancers, as well as in microscopic imaging for histopathology. We also highlight the potential of future developments in technological capabilities and their clinical implications, which we anticipate will lead to PAI becoming a desirable and widely used imaging modality in oncological research and practice.",
"doi": "10.1038/s41571-022-00615-3",
"issn": "1759-4774",
"publisher": "Nature Publishing Group",
"publication": "Nature Reviews Clinical Oncology",
"publication_date": "2022-06",
"series_number": "6",
"volume": "19",
"issue": "6",
"pages": "365-384"
},
{
"id": "authors:qjyc3-5q160",
"collection": "authors",
"collection_id": "qjyc3-5q160",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220512-346447700",
"type": "article",
"title": "Deep learning acceleration of multiscale superresolution localization photoacoustic imaging",
"author": [
{
"family_name": "Kim",
"given_name": "Jongbeom",
"clpid": "Kim-Jongbeom"
},
{
"family_name": "Kim",
"given_name": "Gyuwon",
"orcid": "0000-0002-7259-099X",
"clpid": "Kim-Gyuwon"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Zhang",
"given_name": "Pengfei",
"orcid": "0000-0003-2674-3825",
"clpid": "Zhang-Pengfei"
},
{
"family_name": "Kim",
"given_name": "Jin Young",
"orcid": "0000-0002-7375-8328",
"clpid": "Kim-Jin-Young"
},
{
"family_name": "Kim",
"given_name": "Yeonggeun",
"orcid": "0000-0002-3962-8183",
"clpid": "Kim-Yeonggeun"
},
{
"family_name": "Kim",
"given_name": "Hyung Ham",
"orcid": "0000-0002-6353-5550",
"clpid": "Kim-Hyung-Ham"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Lee",
"given_name": "Seungchul",
"orcid": "0000-0002-1034-1410",
"clpid": "Lee-Seungchul"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"orcid": "0000-0001-7249-1257",
"clpid": "Kim-Chulhong"
}
],
"abstract": "A superresolution imaging approach that localizes very small targets, such as red blood cells or droplets of injected photoacoustic dye, has significantly improved spatial resolution in various biological and medical imaging modalities. However, this superior spatial resolution is achieved by sacrificing temporal resolution because many raw image frames, each containing the localization target, must be superimposed to form a sufficiently sampled high-density superresolution image. Here, we demonstrate a computational strategy based on deep neural networks (DNNs) to reconstruct high-density superresolution images from far fewer raw image frames. The localization strategy can be applied for both 3D label-free localization optical-resolution photoacoustic microscopy (OR-PAM) and 2D labeled localization photoacoustic computed tomography (PACT). For the former, the required number of raw volumetric frames is reduced from tens to fewer than ten. For the latter, the required number of raw 2D frames is reduced by 12 fold. Therefore, our proposed method has simultaneously improved temporal (via the DNN) and spatial (via the localization method) resolutions in both label-free microscopy and labeled tomography. Deep-learning powered localization PA imaging can potentially provide a practical tool in preclinical and clinical studies requiring fast temporal and fine spatial resolutions.",
"doi": "10.1038/s41377-022-00820-w",
"pmcid": "PMC9095876",
"issn": "2047-7538",
"publisher": "Nature Publishing Group",
"publication": "Light: Science & Applications",
"publication_date": "2022-05-12",
"volume": "11",
"pages": "Art. No. 131"
},
{
"id": "authors:djng3-vt411",
"collection": "authors",
"collection_id": "djng3-vt411",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210601-125253304",
"type": "article",
"title": "Massively parallel functional photoacoustic computed tomography of the human brain",
"author": [
{
"family_name": "Na",
"given_name": "Shuai",
"orcid": "0000-0003-2083-0047",
"clpid": "Na-Shuai"
},
{
"family_name": "Russin",
"given_name": "Jonathan J.",
"orcid": "0000-0002-5304-4977",
"clpid": "Russin-Jonathan-J"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Yuan",
"given_name": "Xiaoyun",
"orcid": "0000-0002-7914-3658",
"clpid": "Yuan-Xiaoyun"
},
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Jann",
"given_name": "Kay B.",
"orcid": "0000-0003-3574-0538",
"clpid": "Jann-Kay-B"
},
{
"family_name": "Yan",
"given_name": "Lirong",
"clpid": "Yan-Lirong"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-Konstantin-I"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Wang",
"given_name": "Danny J.",
"orcid": "0000-0002-0840-7062",
"clpid": "Wang-Danny-J"
},
{
"family_name": "Liu",
"given_name": "Charles Y.",
"orcid": "0000-0001-6423-8577",
"clpid": "Liu-Charles-Y"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging of the human brain requires bulky equipment for the generation of magnetic fields. Photoacoustic computed tomography obviates the need for magnetic fields by using light and sound to measure deoxyhaemoglobin and oxyhaemoglobin concentrations to then quantify oxygen saturation and blood volumes. Yet, the available imaging speeds, fields of view (FOV), sensitivities and penetration depths have been insufficient for functional imaging of the human brain. Here, we show that massively parallel ultrasonic transducers arranged hemispherically around the human head can produce tomographic images of the brain with a 10-cm-diameter FOV and spatial and temporal resolutions of 350\u2009\u00b5m and 2\u2009s, respectively. In patients who had a hemicraniectomy, a comparison of functional photoacoustic computed tomography and 7\u2009T BOLD functional magnetic resonance imaging showed a strong spatial correspondence in the same FOV and a high temporal correlation between BOLD signals and photoacoustic signals, with the latter enabling faster detection of functional activation. Our findings establish the use of photoacoustic computed tomography for human brain imaging.",
"doi": "10.1038/s41551-021-00735-8",
"pmcid": "PMC8630100",
"issn": "2157-846X",
"publisher": "Nature Publishing Group",
"publication": "Nature Biomedical Engineering",
"publication_date": "2022-05",
"series_number": "5",
"volume": "6",
"issue": "5",
"pages": "584-592"
},
{
"id": "authors:fdxqb-sqd56",
"collection": "authors",
"collection_id": "fdxqb-sqd56",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220624-382136400",
"type": "article",
"title": "Neurophotonic Tools for Microscopic Measurements and Manipulation: Status Report",
"author": [
{
"family_name": "Abdelfattah",
"given_name": "Ahmed",
"clpid": "Abdelfattah-Ahmed"
},
{
"family_name": "Allu",
"given_name": "Srinivasa Rao"
},
{
"family_name": "Campbell",
"given_name": "Robert E."
},
{
"family_name": "Cheng",
"given_name": "Xiaojun"
},
{
"family_name": "Ci\u017em\u00e1r",
"given_name": "Tom\u00e1\u0161"
},
{
"family_name": "Costantini",
"given_name": "Irene"
},
{
"family_name": "Emiliani",
"given_name": "Valentina"
},
{
"family_name": "Fomin-Thunemann",
"given_name": "Natalie"
},
{
"family_name": "Gilad",
"given_name": "Ariel"
},
{
"family_name": "Fern\u00e1ndez Alfonso",
"given_name": "Tom\u00e1s"
},
{
"family_name": "Ferri",
"given_name": "Christopher G. L."
},
{
"family_name": "Harris",
"given_name": "Andrew"
},
{
"family_name": "Hillman",
"given_name": "Elizabeth M. C."
},
{
"family_name": "Holt",
"given_name": "Matthew G."
},
{
"family_name": "Kili\u00e7",
"given_name": "Kivilcim"
},
{
"family_name": "Miller",
"given_name": "Evan W."
},
{
"family_name": "Mesquita",
"given_name": "Rickson C."
},
{
"family_name": "Nadella",
"given_name": "K. M. Naga Srinivas"
},
{
"family_name": "N\u00e4gerl",
"given_name": "U. Valentin"
},
{
"family_name": "Perez Campos",
"given_name": "Citlali"
},
{
"family_name": "Puppo",
"given_name": "Francesca"
},
{
"family_name": "Shoham",
"given_name": "Shy"
},
{
"family_name": "Silver",
"given_name": "R. Angus"
},
{
"family_name": "Srinivasan",
"given_name": "Vivek J."
},
{
"family_name": "Thunemann",
"given_name": "Martin"
},
{
"family_name": "Tian",
"given_name": "Lei"
},
{
"family_name": "Vinogradov",
"given_name": "Sergei A."
},
{
"family_name": "Vitale",
"given_name": "Flavia"
},
{
"family_name": "Uhlirova",
"given_name": "Hana"
},
{
"family_name": "Xu",
"given_name": "Chris"
},
{
"family_name": "Yang",
"given_name": "Mu-Han"
},
{
"family_name": "Zhao",
"given_name": "Yongxin"
},
{
"family_name": "Ahuja",
"given_name": "Sapna"
},
{
"family_name": "Akkin",
"given_name": "Taner"
},
{
"family_name": "Brake",
"given_name": "Joshua",
"orcid": "0000-0002-5113-6886"
},
{
"family_name": "Boas",
"given_name": "David A."
},
{
"family_name": "Buckley",
"given_name": "Erin M."
},
{
"family_name": "Chen",
"given_name": "Anderson I."
},
{
"family_name": "De Vittorio",
"given_name": "Massimo"
},
{
"family_name": "Devor",
"given_name": "Anna"
},
{
"family_name": "Doran",
"given_name": "Patrick"
},
{
"family_name": "El Khatib",
"given_name": "Mirna"
},
{
"family_name": "Fainman",
"given_name": "Yeshaiahu"
},
{
"family_name": "Han",
"given_name": "Xue"
},
{
"family_name": "Hochgeschwender",
"given_name": "Ute"
},
{
"family_name": "Ji",
"given_name": "Na"
},
{
"family_name": "Lake",
"given_name": "Evelyn"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Li",
"given_name": "Tianqi"
},
{
"family_name": "Machler",
"given_name": "Philipp"
},
{
"family_name": "Nasu",
"given_name": "Yusuke"
},
{
"family_name": "Nimmerjahn",
"given_name": "Axel",
"orcid": "0000-0002-0875-7855"
},
{
"family_name": "Ondr\u00e1ckov\u00e1",
"given_name": "Petra"
},
{
"family_name": "Pavone",
"given_name": "Francesco S."
},
{
"family_name": "Peterka",
"given_name": "Darcy"
},
{
"family_name": "Pisano",
"given_name": "Filippo"
},
{
"family_name": "Pisanello",
"given_name": "Ferruccio"
},
{
"family_name": "Sabatini",
"given_name": "Bernardo L."
},
{
"family_name": "Sadegh",
"given_name": "Sanaz"
},
{
"family_name": "Sakad\u017eic",
"given_name": "Sava"
},
{
"family_name": "Shroff",
"given_name": "Sanaya N."
},
{
"family_name": "Sims",
"given_name": "Ruth R."
},
{
"family_name": "Smith",
"given_name": "Spencer LaVere"
},
{
"family_name": "Tian",
"given_name": "Lin",
"orcid": "0000-0001-7012-6926"
},
{
"family_name": "Troxler",
"given_name": "Thomas"
},
{
"family_name": "Valera",
"given_name": "Antoine"
},
{
"family_name": "Vaziri",
"given_name": "Alipasha"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Yang",
"given_name": "Changhuei",
"orcid": "0000-0001-8791-0354",
"clpid": "Yang-Changhuei"
},
{
"family_name": "Yellen",
"given_name": "Gary"
},
{
"family_name": "Yizhar",
"given_name": "Ofer",
"orcid": "0000-0003-4228-1448",
"clpid": "Yizhar-Ofer"
}
],
"abstract": "Neurophotonics was launched in 2014 coinciding with the launch of the BRAIN Initiative focused on development of technologies for advancement of neuroscience. For the last seven years, Neurophotonics' agenda has been well aligned with this focus on neurotechnologies featuring new optical methods and tools applicable to brain studies. While the BRAIN Initiative 2.0 is pivoting towards applications of these novel tools in the quest to understand the brain, in this article we review an extensive and diverse toolkit of novel methods to explore brain function that have emerged from the BRAIN Initiative and related large-scale efforts for measurement and manipulation of brain structure and function. Here, we focus on neurophotonic tools mostly applicable to animal studies. A companion article, scheduled to appear later this year, will cover diffuse optical imaging methods applicable to noninvasive human studies. For each domain, we outline the current state-of-the-art of the respective technologies, identify the areas where innovation is needed and provide an outlook for the future directions.",
"doi": "10.1117/1.nph.9.s1.013001",
"pmcid": "PMC9047450",
"issn": "2329-423X",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Neurophotonics",
"publication_date": "2022-04-27",
"series_number": "S1",
"volume": "9",
"issue": "S1",
"pages": "Art. No. 013001"
},
{
"id": "authors:vzvys-6rt97",
"collection": "authors",
"collection_id": "vzvys-6rt97",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211201-171925356",
"type": "article",
"title": "Probing single-cell oxygen reserve in sickled erythrocytes via in vivo photoacoustic microscopy",
"author": [
{
"family_name": "Ford",
"given_name": "Andria L.",
"orcid": "0000-0003-0605-8943",
"clpid": "Ford-Andria-L"
},
{
"family_name": "Hsu",
"given_name": "Hsun-Chia",
"clpid": "Hsu-Hsun-Chia"
},
{
"family_name": "Binkley",
"given_name": "Michael M.",
"orcid": "0000-0002-7701-7615",
"clpid": "Binkley-Michael-M"
},
{
"family_name": "Rogers",
"given_name": "Stephen",
"orcid": "0000-0002-3941-9912",
"clpid": "Rogers-Stephen"
},
{
"family_name": "Imai",
"given_name": "Toru",
"orcid": "0000-0002-9497-8549",
"clpid": "Imai-Toru"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-Konstantin-I"
},
{
"family_name": "Doctor",
"given_name": "Allan",
"orcid": "0000-0002-6096-6400",
"clpid": "Doctor-Allan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Lee",
"given_name": "Jin-Moo",
"clpid": "Binkley-Jin-Moo"
}
],
"abstract": "Individuals with sickle cell disease (SCD) face ongoing risk of multi-organ ischemia resulting in chronic disability, frequent hospitalizations, and early mortality. The relationship between hemoglobin (Hb) S polymerization, erythrocyte sickling, and tissue ischemia has been of great interest. Oxygen off-loading and increasing deoxy-Hb concentration promote HbS polymerization, the latter, which has been linked to early erythrocyte deformation or \"reversible\" sickling. Eventually, severe polymerization weakens the cell membrane, leading to \"irreversibly\" sickled cells. Whether the degree of polymerization and the cell's morphologic state, in turn, influence oxygen binding and thus, tissue oxygen availability has been of interest, but technically challenging to study in patients. Over two decades, Wang and colleagues developed an imaging platform, photoacoustic microscopy (PAM), which offers two unique aspects compared to other intravital microscopy systems: (1) high resolution in vivo human imaging using the cuticle as the window to a highly organized vascular bed capable of imaging single capillary loops, and (2) measurements of oxy- and deoxy-Hb levels within single capillaries and single erythrocytes. In this study, we aimed to: (1) characterize capillary morphology and hemodynamic/oxygen metabolic properties in the cuticle nailbed of individuals with SCD compared to healthy controls and (2) track single erythrocytes along the capillary loop to obtain measurements of erythrocyte elongation (ellipticity index, EI) and oxygen saturation before and after tissue oxygen exchange. We hypothesized that erythrocyte EI, as an index of HbS polymerization, would be associated with decreased arteriolar oxygen saturation and/or increased oxygen extraction fraction (OEF) across capillaries\u2014representing compromised \"oxygen reserve.\"",
"doi": "10.1002/ajh.26387",
"pmcid": "PMC8671229",
"issn": "0361-8609",
"publisher": "Wiley",
"publication": "American Journal of Hematology",
"publication_date": "2022-01-01",
"series_number": "1",
"volume": "97",
"issue": "1",
"pages": "E11-E14"
},
{
"id": "authors:gqm0h-j0642",
"collection": "authors",
"collection_id": "gqm0h-j0642",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211008-170742502",
"type": "article",
"title": "Multiscale Photoacoustic Tomography of a Genetically Encoded Near\u2010Infrared FRET Biosensor",
"author": [
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Hsu",
"given_name": "Hsun-Chia",
"clpid": "Hsu-Hsun-Chia"
},
{
"family_name": "Verkhusha",
"given_name": "Vladislav V.",
"orcid": "0000-0002-2083-8121",
"clpid": "Verkhusha-Vladislav-V"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Shcherbakova",
"given_name": "Daria M.",
"orcid": "0000-0003-3384-6363",
"clpid": "Shcherbakova-Daria-M"
}
],
"abstract": "Photoacoustic tomography (PAT) with genetically encoded near-infrared probes enables visualization of specific cell populations in vivo at high resolution deeply in biological tissues. However, because of a lack of proper probes, PAT of cellular dynamics remains unexplored. Here, the authors report a near-infrared Forster resonance energy transfer (FRET) biosensor based on a miRFP670-iRFP720 pair of the near-infrared fluorescent proteins, which enables dynamic functional imaging of active biological processes in deep tissues. By photoacoustically detecting the changes in the optical absorption of the miRFP670 FRET-donor, they monitored cell apoptosis in deep tissue at high spatiotemporal resolution using PAT. Specifically, they detected apoptosis in single cells at a resolution of \u22483 \u00b5m in a mouse ear tumor, and in deep brain tumors (>3 mm beneath the scalp) of living mice at a spatial resolution of \u2248150 \u00b5m with a 20 Hz frame rate. These results open the way for high-resolution photoacoustic imaging of dynamic biological processes in deep tissues using NIR biosensors and PAT.",
"doi": "10.1002/advs.202102474",
"pmcid": "PMC8564460",
"issn": "2198-3844",
"publisher": "Wiley",
"publication": "Advanced Science",
"publication_date": "2021-11-03",
"series_number": "21",
"volume": "8",
"issue": "21",
"pages": "Art. No. 2102474"
},
{
"id": "authors:6dswc-b3n80",
"collection": "authors",
"collection_id": "6dswc-b3n80",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210809-152225260",
"type": "article",
"title": "Focusing light into scattering media with ultrasound-induced field perturbation",
"author": [
{
"family_name": "Cheng",
"given_name": "Zhongtao",
"orcid": "0000-0002-9862-2873",
"clpid": "Cheng-Zhongtao"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Focusing light into scattering media, although challenging, is highly desirable in many realms. With the invention of time-reversed ultrasonically encoded (TRUE) optical focusing, acousto-optic modulation was demonstrated as a promising guidestar mechanism for achieving noninvasive and addressable optical focusing into scattering media. Here, we report a new ultrasound-assisted technique, ultrasound-induced field perturbation optical focusing, abbreviated as UFP. Unlike in conventional TRUE optical focusing, where only the weak frequency-shifted first-order diffracted photons due to acousto-optic modulation are useful, here UFP leverages the brighter zeroth-order photons diffracted by an ultrasonic guidestar as information carriers to guide optical focusing. We find that the zeroth-order diffracted photons, although not frequency-shifted, do have a field perturbation caused by the existence of the ultrasonic guidestar. By detecting and time-reversing the differential field of the frequency-unshifted photons when the ultrasound is alternately ON and OFF, we can focus light to the position where the field perturbation occurs inside the scattering medium. We demonstrate here that UFP optical focusing has superior performance to conventional TRUE optical focusing, which benefits from the more intense zeroth-order photons. We further show that UFP optical focusing can be easily and flexibly developed into double-shot realization or even single-shot realization, which is desirable for high-speed wavefront shaping. This new method upsets conventional thinking on the utility of an ultrasonic guidestar and broadens the horizon of light control in scattering media. We hope that it provides a more efficient and flexible mechanism for implementing ultrasound-guided wavefront shaping.",
"doi": "10.1038/s41377-021-00605-7",
"pmcid": "PMC8329210",
"issn": "2047-7538",
"publisher": "Nature Publishing Group",
"publication": "Light: Science & Applications",
"publication_date": "2021-08-02",
"volume": "10",
"pages": "Art. No. 159"
},
{
"id": "authors:wv3ww-68m97",
"collection": "authors",
"collection_id": "wv3ww-68m97",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210803-212102564",
"type": "article",
"title": "Photoacoustic computed tomography for functional human brain imaging [Invited]",
"author": [
{
"family_name": "Na",
"given_name": "Shuai",
"orcid": "0000-0003-2083-0047",
"clpid": "Na-Shuai"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The successes of magnetic resonance imaging and modern optical imaging of human brain function have stimulated the development of complementary modalities that offer molecular specificity, fine spatiotemporal resolution, and sufficient penetration simultaneously. By virtue of its rich optical contrast, acoustic resolution, and imaging depth far beyond the optical transport mean free path (\u223c1 mm in biological tissues), photoacoustic computed tomography (PACT) offers a promising complementary modality. In this article, PACT for functional human brain imaging is reviewed in its hardware, reconstruction algorithms, in vivo demonstration, and potential roadmap.",
"doi": "10.1364/boe.423707",
"pmcid": "PMC8367226",
"issn": "2156-7085",
"publisher": "Optical Society of America",
"publication": "Biomedical Optics Express",
"publication_date": "2021-07-01",
"series_number": "7",
"volume": "12",
"issue": "7",
"pages": "4056-4083"
},
{
"id": "authors:beaxt-kkc26",
"collection": "authors",
"collection_id": "beaxt-kkc26",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220715-855497000",
"type": "article",
"title": "Recent Advances in Photoacoustic Tomography",
"author": [
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) that integrates the molecular contrast of optical imaging with the high spatial resolution of ultrasound imaging in deep tissue has widespread applications in basic biological science, preclinical research, and clinical trials. Recently, tremendous progress has been made in PAT regarding technical innovations, preclinical applications, and clinical translations. Here, we selectively review the recent progresses and advances in PAT, including the development of advanced PAT systems for small-animal and human imaging, newly engineered optical probes for molecular imaging, broad-spectrum PAT for label-free imaging of biological tissues, high-throughput snapshot photoacoustic topography, and integration of machine learning for image reconstruction and processing. We envision that PAT will have further technical developments and more impactful applications in biomedicine.",
"doi": "10.34133/2021/9823268",
"pmcid": "PMC10085577",
"issn": "2765-8031",
"publisher": "American Association for the Advancement of Science",
"publication": "BME Frontiers",
"publication_date": "2021-06-16",
"volume": "2021",
"pages": "9823268"
},
{
"id": "authors:xrndn-zc806",
"collection": "authors",
"collection_id": "xrndn-zc806",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210714-142518068",
"type": "article",
"title": "Perspective on fast-evolving photoacoustic tomography",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Significance: Acoustically detecting the rich optical absorption contrast in biological tissues, photoacoustic tomography (PAT) seamlessly bridges the functional and molecular sensitivity of optical excitation with the deep penetration and high scalability of ultrasound detection. As a result of continuous technological innovations and commercial development, PAT has been playing an increasingly important role in life sciences and patient care, including functional brain imaging, smart drug delivery, early cancer diagnosis, and interventional therapy guidance.\n\nAim: Built on our 2016 tutorial article that focused on the principles and implementations of PAT, this perspective aims to provide an update on the exciting technical advances in PAT. \n\nApproach: This perspective focuses on the recent PAT innovations in volumetric deep-tissue imaging, high-speed wide-field microscopic imaging, high-sensitivity optical ultrasound detection, and machine-learning enhanced image reconstruction and data processing. Representative applications are introduced to demonstrate these enabling technical breakthroughs in biomedical research. \n\nConclusions: We conclude the perspective by discussing the future development of PAT technologies.",
"doi": "10.1117/1.jbo.26.6.060602",
"pmcid": "PMC8244998",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2021-06",
"series_number": "6",
"volume": "26",
"issue": "6",
"pages": "Art. No. 060602"
},
{
"id": "authors:meewk-yd272",
"collection": "authors",
"collection_id": "meewk-yd272",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201027-120806002",
"type": "article",
"title": "Snapshot photoacoustic topography through an ergodic relay of optical absorption in vivo",
"author": [
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Li",
"given_name": "Yang",
"orcid": "0000-0003-3387-1913",
"clpid": "Li-Yang"
},
{
"family_name": "Zhang",
"given_name": "Yide",
"orcid": "0000-0002-9463-3970",
"clpid": "Zhang-Yide"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) has demonstrated versatile biomedical applications, ranging from tracking single cells to monitoring whole-body dynamics of small animals and diagnosing human breast cancer. Currently, PAT has two major implementations: photoacoustic computed tomography (PACT) and photoacoustic microscopy (PAM). PACT uses a multi-element ultrasonic array for parallel detection, which is relatively complex and expensive. In contrast, PAM requires point-by-point scanning with a single-element detector, which has a limited imaging throughput. The trade-off between the system cost and throughput demands a new imaging method. To this end, we have developed photoacoustic topography through an ergodic relay (PATER). PATER can capture a wide-field image with only a single-element ultrasonic detector upon a single laser shot. This protocol describes the detailed procedures for PATER system construction, including component selection, equipment setup and system alignment. A step-by-step guide for in vivo imaging of a mouse brain is provided as an example application. Data acquisition, image reconstruction and troubleshooting procedures are also elaborated. It takes ~130 min to carry out this protocol, including ~60 min for both calibration and snapshot wide-field data acquisition using a laser with a 2-kHz pulse repetition rate. PATER offers low-cost snapshot wide-field imaging of fast dynamics, such as visualizing blood pulse wave propagation and tracking melanoma tumor cell circulation in mice in vivo. We envision that PATER will have wide biomedical applications and anticipate that the compact size of the setup will allow it to be further developed as a wearable device to monitor human vital signs.",
"doi": "10.1038/s41596-020-00487-w",
"pmcid": "PMC8186536",
"issn": "1754-2189",
"publisher": "Nature Publishing Group",
"publication": "Nature Protocols",
"publication_date": "2021-05",
"series_number": "5",
"volume": "16",
"issue": "5",
"pages": "2381-2394"
},
{
"id": "authors:b2wgv-fhe19",
"collection": "authors",
"collection_id": "b2wgv-fhe19",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210421-142406021",
"type": "article",
"title": "Acoustic sensing with light",
"author": [
{
"family_name": "Garrett",
"given_name": "David C.",
"orcid": "0000-0002-9747-8494",
"clpid": "Garrett-David-C"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical acoustic sensors have gained interest for use in photoacoustic imaging systems, but can they dethrone conventional piezoelectric sensors altogether?",
"doi": "10.1038/s41566-021-00804-z",
"issn": "1749-4885",
"publisher": "Nature Publishing Group",
"publication": "Nature Photonics",
"publication_date": "2021-05",
"series_number": "5",
"volume": "15",
"issue": "5",
"pages": "324-326"
},
{
"id": "authors:91na4-n8n08",
"collection": "authors",
"collection_id": "91na4-n8n08",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210416-071920882",
"type": "article",
"title": "Toward photoswitchable electronic pre-resonance stimulated Raman probes",
"author": [
{
"family_name": "Lee",
"given_name": "Dongkwan",
"orcid": "0000-0001-6091-1349",
"clpid": "Lee-Dongkwan"
},
{
"family_name": "Qian",
"given_name": "Chenxi",
"orcid": "0000-0003-4815-5565",
"clpid": "Qian-Chenxi"
},
{
"family_name": "Wang",
"given_name": "Haomin",
"orcid": "0000-0001-7193-8651",
"clpid": "Wang-Haomin"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Miao",
"given_name": "Kun",
"orcid": "0000-0001-6567-3650",
"clpid": "Miao-Kun"
},
{
"family_name": "Du",
"given_name": "Jiajun",
"orcid": "0000-0003-2693-834X",
"clpid": "Du-Jiajun"
},
{
"family_name": "Shcherbakova",
"given_name": "Daria M.",
"orcid": "0000-0003-3384-6363",
"clpid": "Shcherbakova-Daria-M"
},
{
"family_name": "Verkhusha",
"given_name": "Vladislav V.",
"orcid": "0000-0002-2083-8121",
"clpid": "Verkhusha-Vladislav-V"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Wei",
"given_name": "Lu",
"orcid": "0000-0001-9170-2283",
"clpid": "Wei-Lu"
}
],
"abstract": "Reversibly photoswitchable probes allow for a wide variety of optical imaging applications. In particular, photoswitchable fluorescent probes have significantly facilitated the development of super-resolution microscopy. Recently, stimulated Raman scattering (SRS) imaging, a sensitive and chemical-specific optical microscopy, has proven to be a powerful live-cell imaging strategy. Driven by the advances of newly developed Raman probes, in particular the pre-resonance enhanced narrow-band vibrational probes, electronic pre-resonance SRS (epr-SRS) has achieved super-multiplex imaging with sensitivity down to 250 nM and multiplexity up to 24 colors. However, despite the high demand, photoswitchable Raman probes have yet to be developed. Here, we propose a general strategy for devising photoswitchable epr-SRS probes. Toward this goal, we exploit the molecular electronic and vibrational coupling, in which we switch the electronic states of the molecules to four different states to turn their ground-state epr-SRS signals on and off. First, we showed that inducing transitions to both the electronic excited state and triplet state can effectively diminish the SRS peaks. Second, we revealed that the epr-SRS signals can be effectively switched off in red-absorbing organic molecules through light-facilitated transitions to a reduced state. Third, we identified that photoswitchable proteins with near-infrared photoswitchable absorbance, whose states are modulable with their electronic resonances detunable toward and away from the pump photon energy, can function as the photoswitchable epr-SRS probes with desirable sensitivity (<1 \u00b5M) and low photofatigue (>40 cycles). These photophysical characterizations and proof-of-concept demonstrations should advance the development of novel photoswitchable Raman probes and open up the unexplored Raman imaging capabilities.",
"doi": "10.1063/5.0043791",
"pmcid": "PMC8019356",
"issn": "0021-9606",
"publisher": "American Institute of Physics",
"publication": "Journal of Chemical Physics",
"publication_date": "2021-04-07",
"series_number": "13",
"volume": "154",
"issue": "13",
"pages": "Art. No. 135102"
},
{
"id": "authors:8h00y-a5z46",
"collection": "authors",
"collection_id": "8h00y-a5z46",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210224-105013676",
"type": "article",
"title": "Photoacoustic Computed Tomography of Breast Cancer in Response to Neoadjuvant Chemotherapy",
"author": [
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Tong",
"given_name": "Xin",
"orcid": "0000-0003-2002-5638",
"clpid": "Tong-Xin"
},
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Invernizzi",
"given_name": "Marta",
"orcid": "0000-0001-7043-4929",
"clpid": "Invernizzi-Marta"
},
{
"family_name": "Lai",
"given_name": "Lily",
"clpid": "Lai-Lily"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Neoadjuvant chemotherapy (NAC) has contributed to improving breast cancer outcomes, and it would ideally reduce the need for definitive breast surgery in patients who have no residual cancer after NAC treatment. However, there is no reliable noninvasive imaging modality accepted as the routine method to assess response to NAC. Because of the inability to detect complete response, post\u2010NAC surgery remains the standard of care. To overcome this limitation, a single\u2010breath\u2010hold photoacoustic computed tomography (SBH\u2010PACT) system is developed to provide contrast similar to that of contrast\u2010enhanced magnetic resonance imaging, but with much higher spatial and temporal resolution and without injection of contrast chemicals. SBH\u2010PACT images breast cancer patients at three time points: before, during, and after NAC. The analysis of tumor size, blood vascular density, and irregularity in the distribution and morphology of the blood vessels on SBH\u2010PACT accurately identifies response to NAC as confirmed by the histopathological diagnosis. SBH\u2010PACT shows its near\u2010term potential as a diagnostic tool for assessing breast cancer response to systemic treatment by noninvasively measuring the changes in cancer\u2010associated angiogenesis. Further development of SBH\u2010PACT may also enable serial imaging, rather than the use of current invasive biopsies, to diagnose and follow indeterminate breast lesions.",
"doi": "10.1002/advs.202003396",
"pmcid": "PMC8025032",
"issn": "2198-3844",
"publisher": "Wiley",
"publication": "Advanced Science",
"publication_date": "2021-04-07",
"series_number": "7",
"volume": "8",
"issue": "7",
"pages": "Art. No. 2003396"
},
{
"id": "authors:w1ax5-9kx78",
"collection": "authors",
"collection_id": "w1ax5-9kx78",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201005-104057368",
"type": "article",
"title": "Spatiotemporal strategies to identify aggressive biology in precancerous breast biopsies",
"author": [
{
"family_name": "Frankhauser",
"given_name": "David E.",
"clpid": "Frankhauser-David-E"
},
{
"family_name": "Jovanovic\u2010Talisman",
"given_name": "Tijana",
"orcid": "0000-0003-1928-4763",
"clpid": "Jovanovic\u2010Talisman-Tijana"
},
{
"family_name": "Lai",
"given_name": "Lily",
"clpid": "Lai-Lily"
},
{
"family_name": "Yee",
"given_name": "Lisa D.",
"orcid": "0000-0001-8243-1055",
"clpid": "Yee-Lisa-D"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Mahabal",
"given_name": "Ashish",
"orcid": "0000-0003-2242-0244",
"clpid": "Mahabal-A-A"
},
{
"family_name": "Geradts",
"given_name": "Joseph",
"clpid": "Geradts-Joseph"
},
{
"family_name": "Rockne",
"given_name": "Russell C.",
"orcid": "0000-0002-1557-159X",
"clpid": "Rockne-Russell-C"
},
{
"family_name": "Tomsic",
"given_name": "Jerneja",
"clpid": "Tomsic-Jerneja"
},
{
"family_name": "Jones",
"given_name": "Veronica",
"clpid": "Jones-Veronica"
},
{
"family_name": "Sistrunk",
"given_name": "Christopher",
"clpid": "Sistrunk-Christopher"
},
{
"family_name": "Miranda\u2010Carboni",
"given_name": "Gustavo",
"orcid": "0000-0003-1313-9207",
"clpid": "Miranda\u2010Carboni-Gustavo"
},
{
"family_name": "Dietze",
"given_name": "Eric C.",
"clpid": "Dietze-Eric-C"
},
{
"family_name": "Erhunmwunsee",
"given_name": "Loretta",
"orcid": "0000-0002-5847-9312",
"clpid": "Erhunmwunsee-Loretta"
},
{
"family_name": "Hyslop",
"given_name": "Terry",
"orcid": "0000-0002-3930-8876",
"clpid": "Hyslop-Terry"
},
{
"family_name": "Seewaldt",
"given_name": "Victoria L.",
"orcid": "0000-0002-7289-9268",
"clpid": "Seewaldt-Victoria-L"
}
],
"abstract": "Over 90% of breast cancer is cured; yet there remain highly aggressive breast cancers that develop rapidly and are extremely difficult to treat, much less prevent. Breast cancers that rapidly develop between breast image screening are called \"interval cancers.\" The efforts of our team focus on identifying multiscale integrated strategies to identify biologically aggressive precancerous breast lesions. Our goal is to identify spatiotemporal changes that occur prior to development of interval breast cancers. To accomplish this requires integration of new technology. Our team has the ability to perform single cell in situ transcriptional profiling, noncontrast biological imaging, mathematical analysis, and nanoscale evaluation of receptor organization and signaling. These technological innovations allow us to start to identify multidimensional spatial and temporal relationships that drive the transition from biologically aggressive precancer to biologically aggressive interval breast cancer.",
"doi": "10.1002/wsbm.1506",
"issn": "1939-005X",
"publisher": "Wiley",
"publication": "Wiley Interdisciplinary Reviews: Systems Biology and Medicine",
"publication_date": "2021-03",
"series_number": "2",
"volume": "13",
"issue": "2",
"pages": "Art. No. e1506"
},
{
"id": "authors:4h7en-4y114",
"collection": "authors",
"collection_id": "4h7en-4y114",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210119-143307588",
"type": "article",
"title": "Integration of Multitargeted Polymer-Based Contrast Agents with Photoacoustic Computed Tomography: An Imaging Technique to Visualize Breast Cancer Intratumor Heterogeneity",
"author": [
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Patil",
"given_name": "Deepanjali",
"clpid": "Patil-Deepanjali"
},
{
"family_name": "Petruncio",
"given_name": "Greg",
"orcid": "0000-0002-2527-1064",
"clpid": "Petruncio-Greg"
},
{
"family_name": "Harnden",
"given_name": "Kathleen K.",
"clpid": "Harnden-Kathleen-K"
},
{
"family_name": "Somasekharan",
"given_name": "Jisha V.",
"clpid": "Somasekharan-Jisha-V"
},
{
"family_name": "Paige",
"given_name": "Mikell",
"clpid": "Paige-Mikell"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Salvador-Morales",
"given_name": "Carolina",
"orcid": "0000-0002-2588-6608",
"clpid": "Salvador-Morales-Carolina"
}
],
"abstract": "One of the primary challenges in breast cancer diagnosis and treatment is intratumor heterogeneity (ITH), i.e., the coexistence of different genetically and epigenetically distinct malignant cells within the same tumor. Thus, the identification of ITH is critical for designing better treatments and hence to increase patient survival rates. Herein, we report a noninvasive hybrid imaging technology that integrates multitargeted and multiplexed patchy polymeric photoacoustic contrast agents (MTMPPPCAs) with single-impulse panoramic photoacoustic computed tomography (SIP-PACT). The target specificity ability of MTMPPPCAs to distinguish estrogen and progesterone receptor-positive breast tumors was demonstrated through both fluorescence and photoacoustic measurements and validated by tissue pathology analysis. This work provides the proof-of-concept of the MTMPPPCAs/SIP-PACT system to identify ITH in nonmetastatic tumors, with both high molecular specificity and real-time detection capability.",
"doi": "10.1021/acsnano.0c05893",
"pmcid": "PMC8106867",
"issn": "1936-0851",
"publisher": "American Chemical Society",
"publication": "ACS Nano",
"publication_date": "2021-02-23",
"series_number": "2",
"volume": "15",
"issue": "2",
"pages": "2413-2427"
},
{
"id": "authors:mv4tv-ffm19",
"collection": "authors",
"collection_id": "mv4tv-ffm19",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210209-100707295",
"type": "article",
"title": "High-speed three-dimensional photoacoustic computed tomography for preclinical research and clinical translation",
"author": [
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Tong",
"given_name": "Xin",
"clpid": "Tong-Xin"
},
{
"family_name": "Na",
"given_name": "Shuai",
"orcid": "0000-0003-2083-0047",
"clpid": "Na-Shuai"
},
{
"family_name": "Cao",
"given_name": "Rui",
"orcid": "0000-0003-4444-7528",
"clpid": "Cao-Rui"
},
{
"family_name": "Yuan",
"given_name": "Xiaoyun",
"orcid": "0000-0002-7914-3658",
"clpid": "Yuan-Xiaoyun"
},
{
"family_name": "Garrett",
"given_name": "David C.",
"clpid": "Garrett-David-C"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-Konstantin-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic computed tomography (PACT) has generated increasing interest for uses in preclinical research and clinical translation. However, the imaging depth, speed, and quality of existing PACT systems have previously limited the potential applications of this technology. To overcome these issues, we developed a three-dimensional photoacoustic computed tomography (3D-PACT) system that features large imaging depth, scalable field of view with isotropic spatial resolution, high imaging speed, and superior image quality. 3D-PACT allows for multipurpose imaging to reveal detailed angiographic information in biological tissues ranging from the rodent brain to the human breast. In the rat brain, we visualize whole brain vasculatures and hemodynamics. In the human breast, an in vivo imaging depth of 4\u2009cm is achieved by scanning the breast within a single breath hold of 10\u2009s. Here, we introduce the 3D-PACT system to provide a unique tool for preclinical research and an appealing prototype for clinical translation.",
"doi": "10.1038/s41467-021-21232-1",
"issn": "2041-1723",
"publisher": "Nature Publishing Group",
"publication": "Nature Communications",
"publication_date": "2021-02-09",
"volume": "12",
"pages": "Art. No. 882"
},
{
"id": "authors:dqsbe-9e424",
"collection": "authors",
"collection_id": "dqsbe-9e424",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210113-125945796",
"type": "article",
"title": "Real-time observation and control of optical chaos",
"author": [
{
"family_name": "Fan",
"given_name": "Linran",
"orcid": "0000-0002-5498-7352",
"clpid": "Fan-Linran"
},
{
"family_name": "Yan",
"given_name": "Xiaodong",
"orcid": "0000-0002-7737-6984",
"clpid": "Yan-Xiaodong"
},
{
"family_name": "Wang",
"given_name": "Han",
"orcid": "0000-0002-1933-5762",
"clpid": "Wang-Han"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical chaotic system is a central research topic due to its scientific importance and practical relevance in key photonic applications such as laser optics and optical communication. Because of the ultrafast propagation of light, all previous studies on optical chaos are based on either static imaging or spectral measurement, which shows only time-averaged phenomena. The ability to reveal real-time optical chaotic dynamics and, hence, control its behavior is critical to the further understanding and engineering of these systems. Here, we report a real-time spatial-temporal imaging of an optical chaotic system, using compressed ultrafast photography. The time evolution of the system's phase map is imaged without repeating measurement. We also demonstrate the ability to simultaneously control and monitor optical chaotic systems in real time. Our work introduces a new angle to the study of nonrepeatable optical chaos, paving the way for fully understanding and using chaotic systems in various disciplines.",
"doi": "10.1126/sciadv.abc8448",
"pmcid": "PMC7806228",
"issn": "2375-2548",
"publisher": "American Association for the Advancement of Science",
"publication": "Science Advances",
"publication_date": "2021-01-13",
"series_number": "3",
"volume": "7",
"issue": "3",
"pages": "Art. No. eabc8448"
},
{
"id": "authors:q7xfa-t9867",
"collection": "authors",
"collection_id": "q7xfa-t9867",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201208-105038694",
"type": "article",
"title": "NIH Workshop 2018: Towards Minimally Invasive or Noninvasive Approaches to Assess Tissue Oxygenation Pre- and Post-transfusion",
"author": [
{
"family_name": "Ochocinska",
"given_name": "Margaret J.",
"orcid": "0000-0001-7289-3424",
"clpid": "Ochocinska-Margaret-J"
},
{
"family_name": "Spitalnik",
"given_name": "Steven L.",
"orcid": "0000-0002-8528-4561",
"clpid": "Spitalnik-Steven-L"
},
{
"family_name": "Abuhamad",
"given_name": "Alfred",
"clpid": "Abuhamad-Albert"
},
{
"family_name": "Bennett-Guerrero",
"given_name": "Elliott",
"orcid": "0000-0001-8659-8098",
"clpid": "Bennett-Guerrero-Elliott"
},
{
"family_name": "Carlo",
"given_name": "Waldemar A.",
"orcid": "0000-0003-0382-9976",
"clpid": "Carlo-Waldemar-A"
},
{
"family_name": "Cherukuri",
"given_name": "Murali",
"orcid": "0000-0002-7216-7788",
"clpid": "Cherukuri-Murali"
},
{
"family_name": "Doctor",
"given_name": "Allan",
"orcid": "0000-0002-6096-6400",
"clpid": "Doctor-Allan"
},
{
"family_name": "Dzik",
"given_name": "Walter",
"orcid": "0000-0003-3844-4371",
"clpid": "Dzik-Walter"
},
{
"family_name": "Evans",
"given_name": "Conor L.",
"orcid": "0000-0003-2185-6505",
"clpid": "Evans-Conor-L"
},
{
"family_name": "Kuppusamy",
"given_name": "Periannan",
"orcid": "0000-0002-3214-0660",
"clpid": "Kuppusamy-Periannan"
},
{
"family_name": "Le Moan",
"given_name": "Natacha",
"orcid": "0000-0002-1674-4720",
"clpid": "Le-Moan-Natacha"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Luban",
"given_name": "Naomi",
"orcid": "0000-0002-9538-9068",
"clpid": "Luban-Naomi"
},
{
"family_name": "Mohandas",
"given_name": "Narla",
"orcid": "0000-0003-2271-5296",
"clpid": "Mohandas-Narla"
},
{
"family_name": "Patel",
"given_name": "Ravi M.",
"clpid": "Patel-Ravi-M"
},
{
"family_name": "Roback",
"given_name": "John",
"orcid": "0000-0001-9952-2252",
"clpid": "Roback-John"
},
{
"family_name": "Swartz",
"given_name": "Harold",
"orcid": "0000-0001-6057-6587",
"clpid": "Swartz-Harold"
},
{
"family_name": "Textor",
"given_name": "Stephen",
"clpid": "Textor-Stephen"
},
{
"family_name": "Vinogradov",
"given_name": "Sergei",
"orcid": "0000-0002-4649-5534",
"clpid": "Vinogradov-Sergei"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Wisniewski",
"given_name": "Natalie",
"orcid": "0000-0003-2026-740X",
"clpid": "Wisniewski-Natalie-A"
},
{
"family_name": "Glynn",
"given_name": "Simone",
"clpid": "Glynn-Simone"
}
],
"abstract": "Because blood transfusion is one of the most common therapeutic interventions in hospitalized patients, much recent research has focused on improving the storage quality in vitro of donor red blood cells (RBCs) that are then used for transfusion. However, there is a significant need for enhancing our understanding of the efficacy of the transfused RBCs in vivo. To this end, the NIH sponsored a one-and-a-half-day workshop that brought together experts in multiple disciplines relevant to tissue oxygenation (eg, transfusion medicine, critical care medicine, cardiology, neurology, neonatology and pediatrics, bioengineering, biochemistry, and imaging). These individuals presented their latest findings, discussed key challenges, and aimed to identify opportunities for facilitating development of new technologies and/or biomarker panels to assess tissue oxygenation in a minimally-invasive to non-invasive fashion, before and after RBC transfusion.",
"doi": "10.1016/j.tmrv.2020.12.003",
"issn": "0887-7963",
"publisher": "Elsevier",
"publication": "Transfusion Medicine Reviews",
"publication_date": "2021-01",
"series_number": "1",
"volume": "35",
"issue": "1",
"pages": "46-55"
},
{
"id": "authors:ber8w-hz580",
"collection": "authors",
"collection_id": "ber8w-hz580",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201016-131847198",
"type": "article",
"title": "Transcranial photoacoustic computed tomography based on a layered back-projection method",
"author": [
{
"family_name": "Na",
"given_name": "Shuai",
"orcid": "0000-0003-2083-0047",
"clpid": "Na-Shuai"
},
{
"family_name": "Yuan",
"given_name": "Xiaoyun",
"orcid": "0000-0002-7914-3658",
"clpid": "Yuan-Xiaoyun"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Isla",
"given_name": "Julio",
"orcid": "0000-0002-7124-477X",
"clpid": "Isla-Julio-A"
},
{
"family_name": "Garrett",
"given_name": "David",
"orcid": "0000-0002-9747-8494",
"clpid": "Garrett-David-C"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A major challenge of transcranial human brain photoacoustic computed tomography (PACT) is correcting for the acoustic aberration induced by the skull. Here, we present a modified universal back-projection (UBP) method, termed layered UBP (L-UBP), that can de-aberrate the transcranial PA signals by accommodating the skull heterogeneity into conventional UBP. In L-UBP, the acoustic medium is divided into multiple layers: the acoustic coupling fluid layer between the skull and detectors, the skull layer, and the brain tissue layer, which are assigned different acoustic properties. The transmission coefficients and wave conversion are considered at the fluid\u2013skull and skull\u2013tissue interfaces. Simulations of transcranial PACT using L-UBP were conducted to validate the method. Ex vivo experiments with a newly developed three-dimensional PACT system with 1-MHz center frequency demonstrated that L-UBP can substantially improve the image quality compared to conventional UBP.",
"doi": "10.1016/j.pacs.2020.100213",
"pmcid": "PMC7586244",
"issn": "2213-5979",
"publisher": "Elsevier",
"publication": "Photoacoustics",
"publication_date": "2020-12",
"volume": "20",
"pages": "100213"
},
{
"id": "authors:6wpbf-ex685",
"collection": "authors",
"collection_id": "6wpbf-ex685",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200605-131724922",
"type": "article",
"title": "Spatiotemporal Antialiasing in Photoacoustic Computed Tomography",
"author": [
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic computed tomography (PACT) based on a full-ring ultrasonic transducer array is widely used for small animal wholebody and human organ imaging, thanks to its high in-plane resolution and full-view fidelity. However, spatial aliasing in full-ring geometry PACT has not been studied in detail. If the spatial Nyquist criterion is not met, aliasing in spatial sampling causes artifacts in reconstructed images, even when the temporal Nyquist criterion has been satisfied. In this work, we clarified the source of spatial aliasing through spatiotemporal analysis. We demonstrated that the combination of spatial interpolation and temporal filtering can effectively mitigate artifacts caused by aliasing in either image reconstruction or spatial sampling, and we validated this method by both numerical simulations and in vivo experiments.",
"doi": "10.1109/tmi.2020.2998509",
"pmcid": "PMC7654731",
"issn": "0278-0062",
"publisher": "IEEE",
"publication": "IEEE Transactions on Medical Imaging",
"publication_date": "2020-11",
"series_number": "11",
"volume": "39",
"issue": "11",
"pages": "3535-3547"
},
{
"id": "authors:qxsmb-0bw43",
"collection": "authors",
"collection_id": "qxsmb-0bw43",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201030-151256559",
"type": "article",
"title": "Label-free imaging of lipid-rich biological tissues by mid-infrared photoacoustic microscopy",
"author": [
{
"family_name": "He",
"given_name": "Yun",
"orcid": "0000-0001-8430-6370",
"clpid": "He-Yun"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Pleitez",
"given_name": "Miguel A.",
"clpid": "Pleitez-M-A"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wagenaar",
"given_name": "Daniel A.",
"orcid": "0000-0002-6222-761X",
"clpid": "Wagenaar-D-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Significance: Mid-infrared (IR) imaging based on the vibrational transition of biomolecules provides good chemical-specific contrast in label-free imaging of biology tissues, making it a popular tool in both biomedical studies and clinical applications. However, the current technology typically requires thin and dried or extremely flat samples, whose complicated processing limits this technology's broader translation. \n\nAim: To address this issue, we report mid-IR photoacoustic microscopy (PAM), which can readily work with fresh and thick tissue samples, even when they have rough surfaces.\nApproach: We developed a transmission-mode mid-IR PAM system employing an optical parametric oscillation laser operating in the wavelength range from 2.5 to 12\u2009\u03bcm. Due to its high sensitivity to optical absorption and the low ultrasonic attenuation of tissue, our PAM achieved greater probing depth than Fourier transform IR spectroscopy, thus enabling imaging fresh and thick tissue samples with rough surfaces.\nResults: In our spectroscopy study, the CH\u2082 symmetric stretching at 2850\u2009\u2009cm\u207b\u00b9 (3508 nm) was found to be an excellent source of endogenous contrast for lipids. At this wavenumber, we demonstrated label-free imaging of the lipid composition in fresh, manually cut, and unprocessed tissue sections of up to 3-mm thickness. \n\nConclusions: Our technology requires no time-consuming sample preparation procedure and has great potential in both fast clinical histological analysis and fundamental biological studies.",
"doi": "10.1117/1.jbo.25.10.106506",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2020-10-28",
"series_number": "10",
"volume": "25",
"issue": "10",
"pages": "Art. No. 106506"
},
{
"id": "authors:va0dh-eg953",
"collection": "authors",
"collection_id": "va0dh-eg953",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200924-144352173",
"type": "article",
"title": "Single-Shot Time-Reversed Optical Focusing into and through Scattering Media",
"author": [
{
"family_name": "Cheng",
"given_name": "Zhongtao",
"orcid": "0000-0002-9862-2873",
"clpid": "Cheng-Zhongtao"
},
{
"family_name": "Yang",
"given_name": "Jiamiao",
"orcid": "0000-0003-0006-8411",
"clpid": "Yang-Jiamiao"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical time reversal can focus light through or into scattering media, which raises a new possibility for conquering optical diffusion. Because optical time reversal must be completed within the correlation time of speckles, enhancing the speed of time-reversed optical focusing is important for practical applications. Although employing faster digital devices for time-reversal helps, more efficient methodologies are also desired. Here, we report a single-shot time-reversed optical focusing method to minimize the wavefront measurement time. In our approach, all information requisite for optical time reversal is extracted from a single-shot on-axis hologram, and hence, no other preconditions or measurements are required. In particular, we demonstrate the first realization of single-shot time-reversed ultrasonically encoded (TRUE) optical focusing into scattering media. By using the minimum amount of measurement, this work breaks the fundamental speed limit of digitally based time reversal for focusing into and through scattering media and constitutes an important step toward high-speed wavefront shaping applications.",
"doi": "10.1021/acsphotonics.0c01154",
"pmcid": "PMC8317964",
"issn": "2330-4022",
"publisher": "American Chemical Society",
"publication": "ACS Photonics",
"publication_date": "2020-10-21",
"series_number": "10",
"volume": "7",
"issue": "10",
"pages": "2871-2877"
},
{
"id": "authors:35bq6-n2643",
"collection": "authors",
"collection_id": "35bq6-n2643",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201016-101616045",
"type": "article",
"title": "Single-shot stereo-polarimetric compressed ultrafast photography for light-speed observation of high-dimensional optical transients with picosecond resolution",
"author": [
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Wang",
"given_name": "Peng",
"clpid": "Wang-Peng"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Simultaneous and efficient ultrafast recording of multiple photon tags contributes to high-dimensional optical imaging and characterization in numerous fields. Existing high-dimensional optical imaging techniques that record space and polarization cannot detect the photon's time of arrival owing to the limited speeds of the state-of-the-art electronic sensors. Here, we overcome this long-standing limitation by implementing stereo-polarimetric compressed ultrafast photography (SP-CUP) to record light-speed high-dimensional events in a single exposure. Synergizing compressed sensing and streak imaging with stereoscopy and polarimetry, SP-CUP enables video-recording of five photon tags (x, y, z: space; t: time of arrival; and \u03c8: angle of linear polarization) at 100 billion frames per second with a picosecond temporal resolution. We applied SP-CUP to the spatiotemporal characterization of linear polarization dynamics in early-stage plasma emission from laser-induced breakdown. This system also allowed three-dimensional ultrafast imaging of the linear polarization properties of a single ultrashort laser pulse propagating in a scattering medium.",
"doi": "10.1038/s41467-020-19065-5",
"pmcid": "PMC7567836",
"issn": "2041-1723",
"publisher": "Nature Publishing Group",
"publication": "Nature Communications",
"publication_date": "2020-10-16",
"volume": "11",
"pages": "5252"
},
{
"id": "authors:gnv1c-h3e38",
"collection": "authors",
"collection_id": "gnv1c-h3e38",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200923-104855183",
"type": "article",
"title": "EGFR in enterocytes & endothelium and HIF1\u03b1 in enterocytes are dispensable for massive small bowel resection induced angiogenesis",
"author": [
{
"family_name": "Onufer",
"given_name": "Emily J.",
"orcid": "0000-0002-8802-5346",
"clpid": "Onufer-E-J"
},
{
"family_name": "Aladegbami",
"given_name": "Bola",
"clpid": "Aladegbami-B"
},
{
"family_name": "Imai",
"given_name": "Toru",
"orcid": "0000-0002-9497-8549",
"clpid": "Imai-Toru"
},
{
"family_name": "Seiler",
"given_name": "Kristen",
"clpid": "Seiler-K"
},
{
"family_name": "Bajinting",
"given_name": "Adam",
"clpid": "Bajinting-A"
},
{
"family_name": "Courtney",
"given_name": "Cathleen",
"clpid": "Courtney-Cathleen"
},
{
"family_name": "Sutton",
"given_name": "Stephanie",
"clpid": "Sutton-S"
},
{
"family_name": "Bustos",
"given_name": "Aiza",
"clpid": "Bustos-A"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Yeh",
"given_name": "Cheng-Hung",
"clpid": "Yeh-Cheng-Hung"
},
{
"family_name": "Sescleifer",
"given_name": "Anne",
"clpid": "Sescleifer-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Guo",
"given_name": "Jun",
"clpid": "Guo-Jun"
},
{
"family_name": "Warner",
"given_name": "Brad W.",
"clpid": "Warner-B-W"
}
],
"abstract": "Background: Short bowel syndrome (SBS) results from significant loss of small intestinal length. In response to this loss, adaptation occurs, with Epidermal Growth Factor Receptor (EGFR) being a key driver. Besides enhanced enterocyte proliferation, we have revealed that adaptation is associated with angiogenesis. Further, we have found that small bowel resection (SBR) is associated with diminished oxygen delivery and elevated levels of hypoxia-inducible factor 1-alpha (HIF1\u03b1). \n\nMethods: We ablated EGFR in the epithelium and endothelium as well as HIF1\u03b1 in the epithelium, ostensibly the most hypoxic element. Using these mice, we determined the effects of these genetic manipulations on intestinal blood flow after SBR using photoacoustic microscopy (PAM), intestinal adaptation and angiogenic responses. Then, given that endothelial cells require a stromal support cell for efficient vascularization, we ablated EGFR expression in intestinal subepithelial myofibroblasts (ISEMFs) to determine its effects on angiogenesis in a microfluidic model of human small intestine. \n\nResults: Despite immediate increased demand in oxygen extraction fraction measured by PAM in all mouse lines, were no differences in enterocyte and endothelial cell EGFR knockouts or enterocyte HIF1\u03b1 knockouts by POD3. Submucosal capillary density was also unchanged by POD7 in all mouse lines. Additionally, EGFR silencing in ISEMFs did not impact vascular network development in a microfluidic device of human small intestine. \n\nConclusions: Overall, despite the importance of EGFR in facilitating intestinal adaptation after SBR, it had no impact on angiogenesis in three cell types\u2013enterocytes, endothelial cells, and ISEMFs. Epithelial ablation of HIF1\u03b1 also had no impact on angiogenesis in the setting of SBS.",
"doi": "10.1371/journal.pone.0236964",
"pmcid": "PMC7491746",
"issn": "1932-6203",
"publisher": "Public Library of Science",
"publication": "PLoS ONE",
"publication_date": "2020-09-15",
"series_number": "9",
"volume": "15",
"issue": "9",
"pages": "Art. No. e0236964"
},
{
"id": "authors:04v0m-qta27",
"collection": "authors",
"collection_id": "04v0m-qta27",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200713-145728506",
"type": "article",
"title": "Transparent High-Frequency Ultrasonic Transducer for Photoacoustic Microscopy Application",
"author": [
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "He",
"given_name": "Yun",
"orcid": "0000-0001-8430-6370",
"clpid": "He-Yun"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Yung",
"given_name": "Christopher",
"orcid": "0000-0002-7912-6591",
"clpid": "Yung-Christopher-S"
},
{
"family_name": "Hwang",
"given_name": "Jeeseong",
"orcid": "0000-0002-9801-8529",
"clpid": "Hwang-Jeeseong"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"orcid": "0000-0003-1527-3020",
"clpid": "Zhou-Qifa"
}
],
"abstract": "We report the development of an optically transparent high-frequency ultrasonic transducer using lithium niobate single-crystal and indium\u2013tin\u2013oxide electrodes with up to 90% optical transmission in the visible-to-near-infrared spectrum. The center frequency of the transducer was at 36.9 MHz with 33.9%, at \u22126 dB fractional bandwidth. The photoacoustic imaging capability of the fabricated transducer was also demonstrated by successfully imaging a resolution target and mouse-ear vasculatures in vivo , which were irradiated by a 532 nm pulse laser transmitted through the transducer.",
"doi": "10.1109/tuffc.2020.2985369",
"pmcid": "PMC7484980",
"issn": "0885-3010",
"publisher": "IEEE",
"publication": "IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control",
"publication_date": "2020-09",
"series_number": "9",
"volume": "67",
"issue": "9",
"pages": "1848-1853"
},
{
"id": "authors:xf8xg-66j07",
"collection": "authors",
"collection_id": "xf8xg-66j07",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200826-114833895",
"type": "article",
"title": "Harnessing a multi-dimensional fibre laser using genetic wavefront shaping",
"author": [
{
"family_name": "Wei",
"given_name": "Xiaoming",
"orcid": "0000-0001-6136-5335",
"clpid": "Wei-Xiaoming"
},
{
"family_name": "Jing",
"given_name": "Joseph C.",
"orcid": "0000-0002-1283-3232",
"clpid": "Jing-Joseph-C"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The multi-dimensional laser is a fascinating platform not only for the discovery and understanding of new higher-dimensional coherent lightwaves but also for the frontier study of the complex three-dimensional (3D) nonlinear dynamics and solitary waves widely involved in physics, chemistry, biology and materials science. Systemically controlling coherent lightwave oscillation in multi-dimensional lasers, however, is challenging and has largely been unexplored; yet, it is crucial for both designing 3D coherent light fields and unveiling any underlying nonlinear complexities. Here, for the first time, we genetically harness a multi-dimensional fibre laser using intracavity wavefront shaping technology such that versatile lasing characteristics can be manipulated. We demonstrate that the output power, mode profile, optical spectrum and mode-locking operation can be genetically optimized by appropriately designing the objective function of the genetic algorithm. It is anticipated that this genetic and systematic intracavity control technology for multi-dimensional lasers will be an important step for obtaining high-performance 3D lasing and presents many possibilities for exploring multi-dimensional nonlinear dynamics and solitary waves that may enable new applications.",
"doi": "10.1038/s41377-020-00383-8",
"pmcid": "PMC7450085",
"issn": "2047-7538",
"publisher": "Nature Publishing Group",
"publication": "Light: Science & Applications",
"publication_date": "2020-08-26",
"volume": "9",
"pages": "149"
},
{
"id": "authors:jvydz-pk847",
"collection": "authors",
"collection_id": "jvydz-pk847",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200615-102523461",
"type": "article",
"title": "Evolving cervical imaging technologies to predict preterm birth",
"author": [
{
"family_name": "Pizzella",
"given_name": "Stephanie",
"clpid": "Pizzella-S"
},
{
"family_name": "El Helou",
"given_name": "Nicole",
"clpid": "El-Helou-N"
},
{
"family_name": "Chubiz",
"given_name": "Jessica",
"clpid": "Chubiz-J"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Tuuli",
"given_name": "Methodius G.",
"clpid": "Tuuli-M-G"
},
{
"family_name": "England",
"given_name": "Sarah K.",
"orcid": "0000-0003-4247-0281",
"clpid": "England-S-K"
},
{
"family_name": "Stout",
"given_name": "Molly J.",
"orcid": "0000-0001-5171-313X",
"clpid": "Stout-M-J"
}
],
"abstract": "Preterm birth, defined as delivery at less than 37 weeks' gestation, increases maternal-fetal morbidity and mortality and places heavy financial and emotional burdens on families and society. Although premature cervical remodeling is a major factor in many preterm deliveries, how and why this occurs is poorly understood. This review describes existing and emerging imaging techniques and their advantages and disadvantages in assessing cervical remodeling. Brightness mode (B-mode) ultrasound is used to measure the cervical length, currently the gold standard for determining risk of preterm birth. Several new B-mode ultrasound techniques are being developed, including measuring attenuation, cervical gland area, and the cervical consistency index. Shear wave speed can differentiate between soft (ripe) and firm (unripe) cervices by measuring the speed of ultrasound through a tissue. Elastography provides qualitative information regarding cervical stiffness by compressing the tissue with the ultrasound probe. Raman spectroscopy uses a fiber optic probe to assess the biochemical composition of the cervix throughout pregnancy. Second harmonic generation microscopy uses light to quantify changes in collagen fiber structure and size during cervical maturation. Finally, photoacoustic endoscopy records light-induced sound to determine optical characteristics of cervical tissue. In the long term, a combination of several imaging approaches, combined with consideration of clinical epidemiologic characteristics, will likely be required to accurately predict preterm birth.",
"doi": "10.1007/s00281-020-00800-5",
"issn": "1863-2297",
"publisher": "Springer",
"publication": "Seminars In Immunopathology",
"publication_date": "2020-08",
"series_number": "4",
"volume": "42",
"issue": "4",
"pages": "385-396"
},
{
"id": "authors:paf0p-y8e98",
"collection": "authors",
"collection_id": "paf0p-y8e98",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200731-120008233",
"type": "article",
"title": "Multifocal photoacoustic microscopy using a single-element ultrasonic transducer through an ergodic relay",
"author": [
{
"family_name": "Li",
"given_name": "Yang",
"orcid": "0000-0003-3387-1913",
"clpid": "Li-Yang"
},
{
"family_name": "Wong",
"given_name": "Terence T. W.",
"orcid": "0000-0001-6399-758X",
"clpid": "Wong-Terence-T-W"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Hsu",
"given_name": "Hsun-Chia",
"clpid": "Hsu-Hsun-Chia"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical-resolution photoacoustic microscopy (OR-PAM) has demonstrated high-spatial-resolution imaging of optical absorption in biological tissue. To date, most OR-PAM systems rely on mechanical scanning with confocally aligned optical excitation and ultrasonic detection, limiting the wide-field imaging speed of these systems. Although several multifocal OR-PA (MFOR-PA) systems have attempted to address this limitation, they are hindered by the complex design in a constrained physical space. Here, we present a two-dimensional (2D) MFOR-PAM system that utilizes a 2D microlens array and an acoustic ergodic relay. Using a single-element ultrasonic transducer, this system can detect PA signals generated from 400 optical foci in parallel and then raster scan the optical foci patterns to form an MFOR-PAM image. This system improves the imaging resolution of an acoustic ergodic relay system from 220 to 13\u2009\u03bcm and enables 400-folds shorter scanning time than that of a conventional OR-PAM system at the same resolution and laser repetition rate. We demonstrated the imaging ability of the system with both in vitro and in vivo experiments.",
"doi": "10.1038/s41377-020-00372-x",
"pmcid": "PMC7393099",
"issn": "2047-7538",
"publisher": "Nature Publishing Group",
"publication": "Light: Science & Applications",
"publication_date": "2020-07-31",
"volume": "9",
"pages": "Art. No. 135"
},
{
"id": "authors:1c2t1-5rh32",
"collection": "authors",
"collection_id": "1c2t1-5rh32",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200713-095110805",
"type": "article",
"title": "Photoacoustic topography through an ergodic relay for functional imaging and biometric application in vivo",
"author": [
{
"family_name": "Li",
"given_name": "Yang",
"orcid": "0000-0002-4939-8174",
"clpid": "Li-Yang"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Significance: Photoacoustic (PA) tomography has demonstrated versatile biomedical applications. However, an array-based PA computed tomography (PACT) system is complex and expensive, whereas a single-element detector-based scanning PA system is too slow to detect some fast biological dynamics in vivo. New PA imaging methods are sought after. \n\nAim: To overcome these limitations, we developed photoacoustic topography through an ergodic relay (PATER), a novel high-speed imaging system with a single-element detector. \n\nApproach: PATER images widefield PA signals encoded by the acoustic ergodic relay with a single-laser shot. \n\nResults: We applied PATER in vivo to monitor changes in oxygen saturation in a mouse brain and also to demonstrate high-speed matching of vascular patterns for biometric authentication. \n\nConclusions: PATER has achieved a high-speed temporal resolution over a large field of view. Our results suggest that PATER is a promising and economical alternative to PACT for fast imaging.",
"doi": "10.1117/1.jbo.25.7.070501",
"pmcid": "PMC7347463",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2020-07",
"series_number": "7",
"volume": "25",
"issue": "7",
"pages": "Art. No. 070501"
},
{
"id": "authors:7a57a-9jc53",
"collection": "authors",
"collection_id": "7a57a-9jc53",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191022-123341637",
"type": "article",
"title": "Prospects of Photo- and Thermoacoustic Imaging in Neurosurgery",
"author": [
{
"family_name": "Ravina",
"given_name": "Kristine",
"orcid": "0000-0002-0927-5719",
"clpid": "Ravina-K"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Liu",
"given_name": "Charles Y.",
"clpid": "Liu-Charles-Y"
},
{
"family_name": "Thomas",
"given_name": "Debi",
"clpid": "Thomas-Debi"
},
{
"family_name": "Hasson",
"given_name": "Denise",
"clpid": "Hasson-D"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Russin",
"given_name": "Jonathan J.",
"clpid": "Russin-J-J"
}
],
"abstract": "The evolution of neurosurgery has been, and continues to be, closely associated with innovations in technology. Modern neurosurgery is wed to imaging technology and the future promises even more dependence on anatomic and, perhaps more importantly, functional imaging. The photoacoustic phenomenon was described nearly 140 yr ago; however, biomedical applications for this technology have only recently received significant attention. Light-based photoacoustic and microwave-based thermoacoustic technologies represent novel biomedical imaging modalities with broad application potential within and beyond neurosurgery. These technologies offer excellent imaging resolution while generally considered safer, more portable, versatile, and convenient than current imaging technologies. In this review, we summarize the current state of knowledge regarding photoacoustic and thermoacoustic imaging and their potential impact on the field of neurosurgery.",
"doi": "10.1093/neuros/nyz420",
"issn": "0148-396X",
"publisher": "Congress of Neurological Surgeons",
"publication": "Neurosurgery",
"publication_date": "2020-07",
"series_number": "1",
"volume": "87",
"issue": "1",
"pages": "11-24"
},
{
"id": "authors:xf9hx-h1v87",
"collection": "authors",
"collection_id": "xf9hx-h1v87",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200615-113021741",
"type": "article",
"title": "Wave of single-impulse-stimulated fast initial dip in single vessels of mouse brains imaged by high-speed functional photoacoustic microscopy",
"author": [
{
"family_name": "He",
"given_name": "Yun",
"clpid": "He-Yun"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Cao",
"given_name": "Rui",
"clpid": "Cao-Rui"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Significance: The initial dip in hemoglobin-oxygenation response to stimulations is a spatially confined endogenous indicator that is faster than the blood flow response, making it a desired label-free contrast to map the neural activity. A fundamental question is whether a single-impulse stimulus, much shorter than the response delay, could produce an observable initial dip without repeated stimulation. \n\nAim: To answer this question, we report high-speed functional photoacoustic (PA) microscopy to investigate the initial dip in mouse brains. \n\nApproach: We developed a Raman-laser-based dual-wavelength functional PA microscope that can image capillary-level blood oxygenation at a 1-MHz one-dimensional imaging rate. This technology was applied to monitor the hemodynamics of mouse cerebral vasculature after applying an impulse stimulus to the forepaw. \n\nResults: We observed a transient initial dip in cerebral microvessels starting as early as 0.13 s after the onset of the stimulus. The initial dip and the subsequent overshoot manifested a wave pattern propagating across different microvascular compartments. \n\nConclusions: We quantified both spatially and temporally the single-impulse-stimulated microvascular hemodynamics in mouse brains at single-vessel resolution. Fast label-free imaging of single-impulse response holds promise for real-time brain\u2013computer interfaces.",
"doi": "10.1117/1.jbo.25.6.066501",
"pmcid": "PMC7289453",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2020-06",
"series_number": "6",
"volume": "25",
"issue": "6",
"pages": "Art. No. 066501"
},
{
"id": "authors:28ghn-hmv03",
"collection": "authors",
"collection_id": "28ghn-hmv03",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200429-133034733",
"type": "article",
"title": "Single-shot ultrafast imaging attaining 70 trillion frames per second",
"author": [
{
"family_name": "Wang",
"given_name": "Peng",
"clpid": "Wang-Peng"
},
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Real-time imaging of countless femtosecond dynamics requires extreme speeds orders of magnitude beyond the limits of electronic sensors. Existing femtosecond imaging modalities either require event repetition or provide single-shot acquisition with no more than 10\u00b9\u00b3 frames per second (fps) and 3\u2009\u00d7\u200910\u00b2 frames. Here, we report compressed ultrafast spectral photography (CUSP), which attains several new records in single-shot multi-dimensional imaging speeds. In active mode, CUSP achieves both 7\u2009\u00d7\u200910\u00b9\u00b3 fps and 10\u00b3 frames simultaneously by synergizing spectral encoding, pulse splitting, temporal shearing, and compressed sensing\u2014enabling unprecedented quantitative imaging of rapid nonlinear light-matter interaction. In passive mode, CUSP provides four-dimensional (4D) spectral imaging at 0.5\u2009\u00d7\u200910\u00b9\u00b2 fps, allowing the first single-shot spectrally resolved fluorescence lifetime imaging microscopy (SR-FLIM). As a real-time multi-dimensional imaging technology with the highest speeds and most frames, CUSP is envisioned to play instrumental roles in numerous pivotal scientific studies without the need for event repetition.",
"doi": "10.1038/s41467-020-15745-4",
"pmcid": "PMC7190645",
"issn": "2041-1723",
"publisher": "Nature Publishing Group",
"publication": "Nature Communications",
"publication_date": "2020-04-29",
"volume": "11",
"pages": "Art. No. 2091"
},
{
"id": "authors:3d8bt-3d370",
"collection": "authors",
"collection_id": "3d8bt-3d370",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200428-091451895",
"type": "article",
"title": "Spatio-temporal-spectral imaging of non-repeatable dissipative soliton dynamics",
"author": [
{
"family_name": "Jing",
"given_name": "Joseph C.",
"orcid": "0000-0002-1283-3232",
"clpid": "Jing-Joseph-C"
},
{
"family_name": "Wei",
"given_name": "Xiaoming",
"orcid": "0000-0001-6136-5335",
"clpid": "Wei-Xiaoming"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Dissipative solitons (DSs) are multi-dimensionally localized waves that arise from complex dynamical balances in far-from-equilibrium nonlinear systems and widely exist in physics, chemistry and biology. Real-time observations of DS dynamics across many dimensions thus have a broad impact on unveiling various nonlinear complexities in different fields. However, these observations are challenging as DS transitions are stochastic, non-repeatable and often strongly coupled across spatio-temporal-spectral (STS) domains. Here we report multi-dimensional (space xy\u2009+\u2009discrete time t\u2009+\u2009wavelength \u03bb) DS dynamics imaged by STS compressed ultrafast photography, enabling imaging at up to trillions of frames per second. Various transient and random phenomena of multimode DSs are revealed, highlighting the importance of real-time multi-dimensional observation without the need for event repetition in decomposing the complexities of DSs.",
"doi": "10.1038/s41467-020-15900-x",
"pmcid": "PMC7189376",
"issn": "2041-1723",
"publisher": "Nature Publishing Group",
"publication": "Nature Communications",
"publication_date": "2020-04-28",
"volume": "11",
"pages": "Art. No. 2059"
},
{
"id": "authors:kecz0-wc052",
"collection": "authors",
"collection_id": "kecz0-wc052",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200226-132116150",
"type": "article",
"title": "Fighting against fast speckle decorrelation for light focusing inside live tissue by photon frequency shifting",
"author": [
{
"family_name": "Yang",
"given_name": "Jiamiao",
"orcid": "0000-0003-0006-8411",
"clpid": "Yang-Jiamiao"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Li",
"given_name": "Jingwei",
"orcid": "0000-0003-4927-1066",
"clpid": "Li-Jingwei"
},
{
"family_name": "Cheng",
"given_name": "Zhongtao",
"orcid": "0000-0002-9862-2873",
"clpid": "Cheng-Zhongtao"
},
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Light focusing inside live tissue by digital optical phase conjugation (DOPC) has drawn increasing interest due to its potential biomedical applications in optogenetics, microsurgery, phototherapy, and deep-tissue imaging. However, fast physiological motions in a live animal, including blood flow and respiratory motions, produce undesired photon perturbation and thus inevitably deteriorate the performance of light focusing. Here, we develop a photon-frequency-shifting DOPC method to fight against fast physiological motions by switching the states of a guide star at a distinctive frequency. Therefore, the photons tagged by the guide star are well detected at the specific frequency, separating them from the photons perturbed by fast motions. Light focusing was demonstrated in both phantoms in vitro and mice in vivo with substantially improved focusing contrast. This work puts a new perspective on light focusing inside live tissue and promises wide biomedical applications.",
"doi": "10.1021/acsphotonics.0c00027",
"pmcid": "PMC8188831",
"issn": "2330-4022",
"publisher": "American Chemical Society",
"publication": "ACS Photonics",
"publication_date": "2020-03-18",
"series_number": "3",
"volume": "7",
"issue": "3",
"pages": "837-844"
},
{
"id": "authors:n3rrf-6d833",
"collection": "authors",
"collection_id": "n3rrf-6d833",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200316-151904349",
"type": "article",
"title": "Label-free high-throughput photoacoustic tomography of suspected circulating melanoma tumor cells in patients in vivo",
"author": [
{
"family_name": "Hai",
"given_name": "Pengfei",
"clpid": "Hai-Pengfei"
},
{
"family_name": "Qu",
"given_name": "Yuan",
"clpid": "Qu-Yuan"
},
{
"family_name": "Li",
"given_name": "Yang",
"orcid": "0000-0002-4939-8174",
"clpid": "Li-Yang"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Shmuylovich",
"given_name": "Leonid",
"clpid": "Shmuylovich-L"
},
{
"family_name": "Cornelius",
"given_name": "Lynn A.",
"clpid": "Cornelius-L-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Significance: Detection and characterization of circulating tumor cells (CTCs), a key determinant of metastasis, are critical for determining risk of disease progression, understanding metastatic pathways, and facilitating early clinical intervention. \n\nAim: We aim to demonstrate label-free imaging of suspected melanoma CTCs. \n\nApproach: We use a linear-array-based photoacoustic tomography system (LA-PAT) to detect melanoma CTCs, quantify their contrast-to-noise ratios (CNRs), and measure their flow velocities in most of the superficial veins in humans. \n\nResults: With LA-PAT, we successfully imaged suspected melanoma CTCs in patients in vivo, with a CNR >9. CTCs were detected in 3 of 16 patients with stage III or IV melanoma. Among the three CTC-positive patients, two had disease progression; among the 13 CTC-negative patients, 4 showed disease progression. \n\nConclusions: We suggest that LA-PAT can detect suspected melanoma CTCs in patients in vivo and has potential clinical applications for disease monitoring in melanoma.",
"doi": "10.1117/1.jbo.25.3.036002",
"pmcid": "PMC7069252",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2020-03",
"series_number": "3",
"volume": "25",
"issue": "3",
"pages": "Art. No. 036002"
},
{
"id": "authors:79jgp-n5347",
"collection": "authors",
"collection_id": "79jgp-n5347",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191101-124901076",
"type": "article",
"title": "Snapshot photoacoustic topography through an ergodic relay for high-throughput imaging of optical absorption",
"author": [
{
"family_name": "Li",
"given_name": "Yang",
"orcid": "0000-0002-4939-8174",
"clpid": "Li-Yang"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Bo",
"given_name": "En",
"orcid": "0000-0002-3437-396X",
"clpid": "Bo-En"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"orcid": "0000-0003-3463-0740",
"clpid": "Wang-Lidai"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Current embodiments of photoacoustic imaging require either serial detection with a single-element ultrasonic transducer or parallel detection with an ultrasonic array, necessitating a trade-off between cost and throughput. Here, we present photoacoustic topography through an ergodic relay (PATER) for low-cost high-throughput snapshot wide-field imaging. Encoding spatial information with randomized temporal signatures through ergodicity, PATER requires only a single-element ultrasonic transducer to capture a wide-field image with a single laser shot. We applied PATER to demonstrate both functional imaging of haemodynamic responses and high-speed imaging of blood pulse wave propagation in mice in vivo. Leveraging the high frame rate of 2\u2009kHz, PATER tracked and localized moving melanoma tumour cells in the mouse brain in vivo, which enabled flow velocity quantification and super-resolution imaging. Among the potential biomedical applications of PATER, wearable devices to monitor human vital signs in particular is envisaged.",
"doi": "10.1038/s41566-019-0576-2",
"pmcid": "PMC8223468",
"issn": "1749-4885",
"publisher": "Nature Publishing Group",
"publication": "Nature Photonics",
"publication_date": "2020-03",
"series_number": "3",
"volume": "14",
"issue": "3",
"pages": "164-170"
},
{
"id": "authors:sxcsj-3ap44",
"collection": "authors",
"collection_id": "sxcsj-3ap44",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200124-142311940",
"type": "article",
"title": "Iterative image reconstruction in transcranial photoacoustic tomography based on the elastic wave equation",
"author": [
{
"family_name": "Poudel",
"given_name": "Joemini",
"clpid": "Poudel-J"
},
{
"family_name": "Na",
"given_name": "Shuai",
"orcid": "0000-0003-2083-0047",
"clpid": "Na-Shuai"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
}
],
"abstract": "Photoacoustic computed tomography (PACT) is an emerging computed imaging modality that exploits optical contrast and ultrasonic detection principles to form images of the photoacoustically induced initial pressure distribution within tissue. The PACT reconstruction problem corresponds to a time-domain inverse source problem, where the initial pressure distribution is recovered from the measurements recorded on an aperture outside the support of the source. A major challenge in transcranial PACT of the brain is to compensate for aberrations and attenuation in the measured data due to the propagation of the photoacoustic wavefields through the skull. To properly account for these effects, a wave equation-based inversion method can be employed that can model the heterogeneous elastic properties of the medium. In this study, an optimization-based image reconstruction method for 3D transcranial PACT is developed based on the elastic wave equation. To accomplish this, a forward-adjoint operator pair based on a finite-difference time-domain discretization of the elastic wave equation is utilized to compute penalized least squares estimates of the initial pressure distribution. Computer-simulation and experimental studies are conducted to investigate the robustness of the reconstruction method to model mismatch and its ability to effectively resolve cortical and superficial brain structures.",
"doi": "10.1088/1361-6560/ab6b46",
"pmcid": "PMC7202377",
"issn": "0031-9155",
"publisher": "IOP",
"publication": "Physics in Medicine and Biology",
"publication_date": "2020-03",
"series_number": "5",
"volume": "65",
"issue": "5",
"pages": "Art. No. 055009"
},
{
"id": "authors:267sf-67171",
"collection": "authors",
"collection_id": "267sf-67171",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200219-145055229",
"type": "article",
"title": "Real-time frequency-encoded spatiotemporal focusing through scattering media using a programmable 2D ultrafine optical frequency comb",
"author": [
{
"family_name": "Wei",
"given_name": "Xiaoming",
"orcid": "0000-0001-6136-5335",
"clpid": "Wei-Xiaoming"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Jing",
"given_name": "Joseph C.",
"orcid": "0000-0002-1283-3232",
"clpid": "Jing-Joseph-C"
},
{
"family_name": "Hemphill",
"given_name": "Ashton S.",
"clpid": "Hemphill-A-S"
},
{
"family_name": "Yang",
"given_name": "Changsheng",
"orcid": "0000-0003-3824-1128",
"clpid": "Yang-Changsheng"
},
{
"family_name": "Xu",
"given_name": "Shanhui",
"orcid": "0000-0002-9744-6361",
"clpid": "Xu-Shanhui"
},
{
"family_name": "Yang",
"given_name": "Zhongmin",
"orcid": "0000-0001-6525-0818",
"clpid": "Yang-Zhongmin"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical wavefront shaping is a powerful tool for controlling photons in strongly scattering media. Its speed, however, has been the bottleneck for in vivo applications. Moreover, unlike spatial focusing, temporal focusing from a continuous-wave source has rarely been exploited yet is highly desired for nonlinear photonics. Here, we present a novel real-time frequency-encoded spatiotemporal (FEST) focusing technology. FEST focusing uses a novel programmable two-dimensional optical frequency comb with an ultrafine linewidth to perform single-shot wavefront measurements, with a fast single-pixel detector. This technique enables simultaneous spatial and temporal focusing at microsecond scales through thick dynamic scattering media. This technology also enabled us to discover the large-scale temporal shift, a new phenomenon that, with the conventional spatial memory effect, establishes a space-time duality. FEST focusing opens a new avenue for high-speed wavefront shaping in the field of photonics.",
"doi": "10.1126/sciadv.aay1192",
"pmcid": "PMC7030933",
"issn": "2375-2548",
"publisher": "American Association for the Advancement of Science",
"publication": "Science Advances",
"publication_date": "2020-02-19",
"series_number": "8",
"volume": "6",
"issue": "8",
"pages": "Art. No. eaay1192"
},
{
"id": "authors:938t3-1kt07",
"collection": "authors",
"collection_id": "938t3-1kt07",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200303-152739923",
"type": "article",
"title": "Single-shot compressed ultrafast photography: a review",
"author": [
{
"family_name": "Qi",
"given_name": "Dalong",
"clpid": "Qi-Dalong"
},
{
"family_name": "Zhang",
"given_name": "Shian",
"clpid": "Zhang-Shian"
},
{
"family_name": "Yang",
"given_name": "Chengshuai",
"clpid": "Yang-Chengshuai"
},
{
"family_name": "He",
"given_name": "Yilin",
"clpid": "He-Yilin"
},
{
"family_name": "Cao",
"given_name": "Fengyan",
"clpid": "Cao-Fengyan"
},
{
"family_name": "Yao",
"given_name": "Jiali",
"clpid": "Yao-Jiali"
},
{
"family_name": "Ding",
"given_name": "Pengpeng",
"clpid": "Ding-Pengpeng"
},
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Jia",
"given_name": "Tianqing",
"clpid": "Jia-Tianqing"
},
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Sun",
"given_name": "Zhenrong",
"clpid": "Sun-Zhenrong"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Compressed ultrafast photography (CUP) is a burgeoning single-shot computational imaging technique that provides an imaging speed as high as 10 trillion frames per second and a sequence depth of up to a few hundred frames. This technique synergizes compressed sensing and the streak camera technique to capture nonrepeatable ultrafast transient events with a single shot. With recent unprecedented technical developments and extensions of this methodology, it has been widely used in ultrafast optical imaging and metrology, ultrafast electron diffraction and microscopy, and information security protection. We review the basic principles of CUP, its recent advances in data acquisition and image reconstruction, its fusions with other modalities, and its unique applications in multiple research fields.",
"doi": "10.1117/1.ap.2.1.014003",
"issn": "2577-5421",
"publisher": "Society of Photo-Optical Instrumentation Engineers (SPIE)",
"publication": "Advanced Photonics",
"publication_date": "2020-02",
"series_number": "1",
"volume": "2",
"issue": "1",
"pages": "Art. No. 014003"
},
{
"id": "authors:9tv81-pw371",
"collection": "authors",
"collection_id": "9tv81-pw371",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200319-100830006",
"type": "article",
"title": "Graphics processing unit accelerating compressed sensing photoacoustic computed tomography with total variation",
"author": [
{
"family_name": "Gao",
"given_name": "Mingjie",
"clpid": "Gao-Mingjie"
},
{
"family_name": "Si",
"given_name": "Guangtao",
"clpid": "Si-Guangtao"
},
{
"family_name": "Bai",
"given_name": "Yuanyuan",
"clpid": "Bai-Yuanyuan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Liu",
"given_name": "Chengbo",
"orcid": "0000-0001-7565-2044",
"clpid": "Liu-Chengbo"
},
{
"family_name": "Meng",
"given_name": "Jing",
"orcid": "0000-0002-6991-8878",
"clpid": "Meng-Jing"
}
],
"abstract": "Photoacoustic computed tomography with compressed sensing (CS-PACT) is a commonly used imaging strategy for sparse-sampling PACT. However, it is very time-consuming because of the iterative process involved in the image reconstruction. In this paper, we present a graphics processing unit (GPU)-based parallel computation framework for total-variation-based CS-PACT and adapted into a custom-made PACT system. Specifically, five compute-intensive operators are extracted from the iteration algorithm and are redesigned for parallel performance on a GPU. We achieved an image reconstruction speed 24\u201331 times faster than the CPU performance. We performed in vivo experiments on human hands to verify the feasibility of our developed method.",
"doi": "10.1364/ao.378466",
"issn": "1559-128X",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2020-01-20",
"series_number": "3",
"volume": "59",
"issue": "3",
"pages": "712-719"
},
{
"id": "authors:qwr4e-jy586",
"collection": "authors",
"collection_id": "qwr4e-jy586",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200117-154848286",
"type": "article",
"title": "Picosecond-resolution phase-sensitive imaging of transparent objects in a single shot",
"author": [
{
"family_name": "Kim",
"given_name": "Taewoo",
"clpid": "Kim-Taewoo"
},
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "With the growing interest in the optical imaging of ultrafast phenomena in transparent objects, from shock wave to neuronal action potentials, high contrast imaging at high frame rates has become desirable. While phase sensitivity provides the contrast, the frame rates and sequence depths are highly limited by the detectors. Here, we present phase-sensitive compressed ultrafast photography (pCUP) for single-shot real-time ultrafast imaging of transparent objects by combining the contrast of dark-field imaging with the speed and the sequence depth of CUP. By imaging the optical Kerr effect and shock wave propagation, we demonstrate that pCUP can image light-speed phase signals in a single shot with up to 350 frames captured at up to 1 trillion frames per second. We expect pCUP to be broadly used for a vast range of fundamental and applied sciences.",
"doi": "10.1126/sciadv.aay6200",
"pmcid": "PMC6968941",
"issn": "2375-2548",
"publisher": "American Association for the Advancement of Science",
"publication": "Science Advances",
"publication_date": "2020-01-17",
"series_number": "3",
"volume": "6",
"issue": "3",
"pages": "Art. no. eaay6200"
},
{
"id": "authors:355d9-paf71",
"collection": "authors",
"collection_id": "355d9-paf71",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200220-131412163",
"type": "article",
"title": "Intelligently optimized digital optical phase conjugation with particle swarm optimization",
"author": [
{
"family_name": "Cheng",
"given_name": "Zhongtao",
"orcid": "0000-0002-9862-2873",
"clpid": "Cheng-Zhongtao"
},
{
"family_name": "Yang",
"given_name": "Jiamiao",
"orcid": "0000-0003-0006-8411",
"clpid": "Yang-Jiamiao"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Wavefront shaping (WFS) based on digital optical phase conjugation (DOPC) has gained major interest in focusing light through or inside scattering media. However, the quality of DOPC is greatly limited by imperfections of the system in a complicated and coupled way. In this Letter, we incorporate the concept of global optimization to solve this problem comprehensively for the first time, to the best of our knowledge. An automatic and intelligent optimization framework for DOPC techniques is proposed, leveraging the global optimization ability of particle swarm optimization (PSO). We demonstrate the general and powerful ability of the proposed approach in a series of DOPC-related experiments for focusing through and inside scattering media. This novel work can improve the OPC quality greatly and simplify the development of a high-performance DOPC system, which may open up a new avenue for the general scientific community to benefit from DOPC-based WFS in their potential applications.",
"doi": "10.1364/ol.381930",
"pmcid": "PMC7398265",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2020-01-15",
"series_number": "2",
"volume": "45",
"issue": "2",
"pages": "431-434"
},
{
"id": "authors:2wtas-kmx35",
"collection": "authors",
"collection_id": "2wtas-kmx35",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191212-105211067",
"type": "article",
"title": "Focusing light inside live tissue using reversibly switchable bacterial phytochrome as a genetically encoded photochromic guide star",
"author": [
{
"family_name": "Yang",
"given_name": "Jiamiao",
"orcid": "0000-0003-0006-8411",
"clpid": "Yang-Jiamiao"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Shemetov",
"given_name": "Anton A.",
"clpid": "Shemetov-Anton-A"
},
{
"family_name": "Lee",
"given_name": "Sangjun",
"orcid": "0000-0002-0846-8252",
"clpid": "Lee-Sangjun"
},
{
"family_name": "Zhao",
"given_name": "Yuan",
"clpid": "Zhao-Yuan"
},
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Li",
"given_name": "Jingwei",
"orcid": "0000-0003-4927-1066",
"clpid": "Li-Jingwei"
},
{
"family_name": "Oka",
"given_name": "Yuki",
"orcid": "0000-0003-2686-0677",
"clpid": "Oka-Yuki"
},
{
"family_name": "Verkhusha",
"given_name": "Vladislav V.",
"orcid": "0000-0002-2083-8121",
"clpid": "Verkhusha-Vladislav-V"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Focusing light deep by engineering wavefronts toward guide stars inside scattering media has potential biomedical applications in imaging, manipulation, stimulation, and therapy. However, the lack of endogenous guide stars in biological tissue hinders its translations to in vivo applications. Here, we use a reversibly switchable bacterial phytochrome protein as a genetically encoded photochromic guide star (GePGS) in living tissue to tag photons at targeted locations, achieving light focusing inside the tissue by wavefront shaping. As bacterial phytochrome-based GePGS absorbs light differently upon far-red and near-infrared illumination, a large dynamic absorption contrast can be created to tag photons inside tissue. By modulating the GePGS at a distinctive frequency, we suppressed the competition between GePGS and tissue motions and formed tight foci inside mouse tumors in vivo and acute mouse brain tissue, thus improving light delivery efficiency and specificity. Spectral multiplexing of GePGS proteins with different colors is an attractive possibility.",
"doi": "10.1126/sciadv.aay1211",
"pmcid": "PMC6905864",
"issn": "2375-2548",
"publisher": "American Association for the Advancement of Science",
"publication": "Science Advances",
"publication_date": "2019-12",
"series_number": "12",
"volume": "5",
"issue": "12",
"pages": "Art. No. eaay1211"
},
{
"id": "authors:mdkft-3gj98",
"collection": "authors",
"collection_id": "mdkft-3gj98",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191224-093208136",
"type": "article",
"title": "Special Section Guest Editorial: Celebrating the Exponential Growth of Optoacoustic/Photoacoustic Imaging",
"author": [
{
"family_name": "Beard",
"given_name": "Paul",
"orcid": "0000-0001-7710-2759",
"clpid": "Beard-P-C"
},
{
"family_name": "Anastasio",
"given_name": "Mark",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
},
{
"family_name": "Oraevsky",
"given_name": "Alexander A.",
"orcid": "0000-0002-9212-6211",
"clpid": "Oraevsky-A-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Guest editors introduce contributors to the Special Section Celebrating the Exponential Growth of Optoacoustic/Photoacoustic Imaging. \n\nWe are pleased to introduce the contributions to this JBO Special Section entitled \"Celebrating the Exponential Growth of Biomedical Optoacoustic/Photoacoustic Imaging.\" This title was chosen to reflect the strong growth of the field over the last two and a half decades. The diversity of papers in this special section bears witness to this, with contributions that encompass numerical modelling, advanced instrumentation, functional imaging, clinical translation, and novel biomedical applications.",
"doi": "10.1117/1.jbo.24.12.121901",
"pmcid": "PMC7005571",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2019-12",
"series_number": "12",
"volume": "24",
"issue": "12",
"pages": "Art. No. 121901"
},
{
"id": "authors:m6agq-5nn35",
"collection": "authors",
"collection_id": "m6agq-5nn35",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191121-080437719",
"type": "article",
"title": "Physical picture of the optical memory effect",
"author": [
{
"family_name": "Liu",
"given_name": "Honglin",
"orcid": "0000-0003-2473-9056",
"clpid": "Liu-Honglin"
},
{
"family_name": "Liu",
"given_name": "Zhentao",
"orcid": "0000-0002-4453-8043",
"clpid": "Liu-Zhentao"
},
{
"family_name": "Chen",
"given_name": "Meijun",
"clpid": "Chen-Meijun"
},
{
"family_name": "Han",
"given_name": "Shensheng",
"clpid": "Han-Shensheng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The optical memory effect is an interesting phenomenon that has attracted considerable attention in recent decades. Here, we present a new physical picture of the optical memory effect, in which the memory effect and the conventional spatial shift invariance are united. Based on this picture we depict the role of thickness, scattering times, and anisotropy factor and derive equations to calculate the ranges of the angular memory effect (AME) of different scattering components (ballistic light, singly scattered, doubly scattered, etc.), and hence a more accurate equation for the real AME ranges of volumetric turbid media. A conventional random phase mask model is modified according to the new picture. The self-consistency of the simulation model and its agreement with the experiment demonstrate the rationality of the model and the physical picture, which provide powerful tools for more sophisticated studies of the memory-effect-related phenomena and wavefront-sensitive techniques, such as wavefront shaping, optical phase conjugation, and optical trapping in/through scattering media.",
"doi": "10.1364/prj.7.001323",
"issn": "2327-9125",
"publisher": "Optical Society of America",
"publication": "Photonics Research",
"publication_date": "2019-11-01",
"series_number": "11",
"volume": "7",
"issue": "11",
"pages": "1323-1330"
},
{
"id": "authors:swtbs-9aq76",
"collection": "authors",
"collection_id": "swtbs-9aq76",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190402-152949369",
"type": "article",
"title": "High-resolution, high-contrast mid-infrared imaging of fresh biological samples with ultraviolet-localized photoacoustic microscopy",
"author": [
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Wong",
"given_name": "Terence T. W.",
"orcid": "0000-0001-6399-758X",
"clpid": "Wong-Terence-T-W"
},
{
"family_name": "He",
"given_name": "Yun",
"clpid": "He-Yun"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Yung",
"given_name": "Christopher S.",
"orcid": "0000-0002-7912-6591",
"clpid": "Yung-Christopher-S"
},
{
"family_name": "Hwang",
"given_name": "Jeeseong",
"clpid": "Hwang-Jeeseong"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-Konstantin-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Mid-infrared (MIR) microscopy provides rich chemical and structural information about biological samples, without staining. Conventionally, the long MIR wavelength severely limits the lateral resolution owing to optical diffraction; moreover, the strong MIR absorption of water ubiquitous in fresh biological samples results in high background and low contrast. To overcome these limitations, we propose a method that employs photoacoustic detection highly localized with a pulsed ultraviolet laser on the basis of the Gr\u00fcneisen relaxation effect. For cultured cells, our method achieves water-background suppressed MIR imaging of lipids and proteins at ultraviolet resolution, at least an order of magnitude finer than the MIR diffraction limits. Label-free histology using this method is also demonstrated in thick brain slices. Our approach provides convenient high-resolution and high-contrast MIR imaging, which can benefit the diagnosis of fresh biological samples.",
"doi": "10.1038/s41566-019-0441-3",
"pmcid": "PMC6705424",
"issn": "1749-4885",
"publisher": "Nature Publishing Group",
"publication": "Nature Photonics",
"publication_date": "2019-09",
"series_number": "9",
"volume": "13",
"issue": "9",
"pages": "609-615"
},
{
"id": "authors:0jam3-d5733",
"collection": "authors",
"collection_id": "0jam3-d5733",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190724-151755826",
"type": "article",
"title": "A microrobotic system guided by photoacoustic computed tomography for targeted navigation in intestines in vivo",
"author": [
{
"family_name": "Wu",
"given_name": "Zhiguang",
"clpid": "Wu-Zhiguang"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Yang",
"given_name": "Yiran",
"orcid": "0000-0001-8770-8746",
"clpid": "Yang-Yiran"
},
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Li",
"given_name": "Yang",
"orcid": "0000-0002-4939-8174",
"clpid": "Li-Yang"
},
{
"family_name": "Yang",
"given_name": "So-Yoon",
"clpid": "Yang-So-Yoon"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Gao",
"given_name": "Wei",
"orcid": "0000-0002-8503-4562",
"clpid": "Gao-Wei"
}
],
"abstract": "Recently, tremendous progress in synthetic micro/nanomotors in diverse environment has been made for potential biomedical applications. However, existing micro/nanomotor platforms are inefficient for deep tissue imaging and motion control in vivo. Here, we present a photoacoustic computed tomography (PACT)\u2013guided investigation of micromotors in intestines in vivo. The micromotors enveloped in microcapsules are stable in the stomach and exhibit efficient propulsion in various biofluids once released. The migration of micromotor capsules toward the targeted regions in intestines has been visualized by PACT in real time in vivo. Near-infrared light irradiation induces disintegration of the capsules to release the cargo-loaded micromotors. The intensive propulsion of the micromotors effectively prolongs the retention in intestines. The integration of the newly developed microrobotic system and PACT enables deep imaging and precise control of the micromotors in vivo and promises practical biomedical applications, such as drug delivery.",
"doi": "10.1126/scirobotics.aax0613",
"pmcid": "PMC7337196",
"issn": "2470-9476",
"publisher": "American Association for the Advancement of Science",
"publication": "Science Robotics",
"publication_date": "2019-07-24",
"series_number": "32",
"volume": "4",
"issue": "32",
"pages": "Art. No. eaax0613"
},
{
"id": "authors:st3x1-9nd12",
"collection": "authors",
"collection_id": "st3x1-9nd12",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190313-094535694",
"type": "article",
"title": "In Vivo Label-free Functional Photoacoustic Monitoring of Ischemic Reperfusion",
"author": [
{
"family_name": "Bi",
"given_name": "Renzhe",
"clpid": "Bi-Renzhe"
},
{
"family_name": "Dinish",
"given_name": "U. S.",
"clpid": "Dinish-U-S"
},
{
"family_name": "Goh",
"given_name": "Chi Ching",
"clpid": "Goh-Chi-Ching"
},
{
"family_name": "Imai",
"given_name": "Toru",
"orcid": "0000-0002-9497-8549",
"clpid": "Imai-Toru"
},
{
"family_name": "Moothanchery",
"given_name": "Mohesh",
"clpid": "Moothanchery-M"
},
{
"family_name": "Li",
"given_name": "Xiuting",
"clpid": "Li-Xiuting"
},
{
"family_name": "Kim",
"given_name": "Jin Young",
"clpid": "Kim-Jin-Young"
},
{
"family_name": "Jeon",
"given_name": "Seungwan",
"clpid": "Jeon-Seungwan"
},
{
"family_name": "Pu",
"given_name": "Yang",
"clpid": "Pu-Yang"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Ng",
"given_name": "Lai Guan",
"clpid": "Ng-Lai-Guan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Olivo",
"given_name": "Malini",
"clpid": "Olivo-M"
}
],
"abstract": "Pressure ulcer (PU) formation is a common problem among patients confined to bed or restricted to wheelchairs. The ulcer forms when the affected skin and underlying tissues go through repeated cycles of ischemia and reperfusion, leading to inflammation. This theory is evident by intravital imaging studies performed in immune cell\u2010specific, fluorescent reporter mouse skin with induced ischemia\u2010reperfusion (I\u2010R) injuries. However, traditional confocal or multi\u2010photon microscopy cannot accurately monitor the progression of vascular reperfusion by contrast agents, which leaks into the interstitium under inflammatory conditions. Here, we develop a dual\u2010wavelength micro electro mechanical system (MEMS) scanning based optical resolution photoacoustic microscopy (OR\u2010PAM) system for continuous label\u2010free functional imaging of vascular reperfusion in an IR mouse model. This MEMS\u2010OR\u2010PAM system provides fast scanning speed for concurrent dual\u2010wavelength imaging, which enables continuous monitoring of the reperfusion process. During reperfusion, the revascularization of blood vessels and the oxygen saturation (sO_2) changes in both arteries and Illustration of the vascular reperfusion of the ear skin. veins are recorded, from which the local oxygen extraction ratios of the ischemic tissue and the unaffected tissue can be quantified. Our MEMS\u2010OR\u2010PAM system provides novel perspectives to understand the I\u2010R injuries. It solves the problem of dynamic label\u2010free functional monitoring of the vascular reperfusion at high spatial resolution.",
"doi": "10.1002/jbio.201800454",
"issn": "1864-063X",
"publisher": "Wiley",
"publication": "Journal of Biophotonics",
"publication_date": "2019-07",
"series_number": "7",
"volume": "12",
"issue": "7",
"pages": "Art. No. e201800454"
},
{
"id": "authors:zhbct-fzn73",
"collection": "authors",
"collection_id": "zhbct-fzn73",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190613-121001178",
"type": "article",
"title": "Dual-polarization analog optical phase conjugation for focusing light through scattering media",
"author": [
{
"family_name": "Cheng",
"given_name": "Zhongtao",
"orcid": "0000-0002-9862-2873",
"clpid": "Cheng-Zhongtao"
},
{
"family_name": "Yang",
"given_name": "Jiamiao",
"orcid": "0000-0003-0006-8411",
"clpid": "Yang-Jiamiao"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Focusing light through or inside scattering media by the analog optical phase conjugation (AOPC) technique based on photorefractive crystals (PRCs) has been intensively investigated due to its high controlled degrees of freedom and short response time. However, the existing AOPC systems only phase-conjugate the scattered light in one polarization direction, while the polarization state of light scattered through a thick scattering medium is spatially random in general, which means that half of the scattering information is lost. Here, we propose dual-polarization AOPC for focusing light through scattering media to improve the efficiency and fidelity in the phase conjugation. The motivations of the dual-polarization AOPC are illustrated by theoretical analysis and numerical simulation, and then an experimental system is established to realize the dual-polarization AOPC. By separating and rotating the two orthogonal polarization components of the randomly polarized scattered light, light in all polarization states is recorded and phase-conjugated using the same PRC. Experimental results for focusing through a thick biological tissue show that the intensity of the time-reversed focus from the dual-polarization AOPC can be enhanced by a factor of approximate four compared with the existing single-polarization AOPC.",
"doi": "10.1063/1.5097181",
"pmcid": "PMC6565428",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2019-06-10",
"series_number": "23",
"volume": "114",
"issue": "23",
"pages": "Art. No. 231104"
},
{
"id": "authors:3vty9-ct752",
"collection": "authors",
"collection_id": "3vty9-ct752",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190220-130924008",
"type": "article",
"title": "High-throughput, label-free, single-cell photoacoustic microscopy of intratumoral metabolic heterogeneity",
"author": [
{
"family_name": "Hai",
"given_name": "Pengfei",
"clpid": "Hai-Pengfei"
},
{
"family_name": "Imai",
"given_name": "Toru",
"orcid": "0000-0002-9497-8549",
"clpid": "Imai-Toru"
},
{
"family_name": "Xu",
"given_name": "Song",
"clpid": "Xu-Song"
},
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Aft",
"given_name": "Rebecca L.",
"clpid": "Aft-R-L"
},
{
"family_name": "Zou",
"given_name": "Jun",
"orcid": "0000-0002-9543-6135",
"clpid": "Zou-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Intratumoral heterogeneity, which is manifested in almost all of the hallmarks of cancer, including the significantly altered metabolic profiles of cancer cells, represents a challenge to effective cancer therapy. High-throughput measurements of the metabolism of individual cancer cells would allow direct visualization and quantification of intratumoral metabolic heterogeneity, yet the throughputs of current measurement techniques are limited to about 120 cells per hour. Here, we show that single-cell photoacoustic microscopy can reach throughputs of approximately 12,000 cells per hour by trapping single cells with blood in an oxygen-diffusion-limited high-density microwell array and by using photoacoustic imaging to measure the haemoglobin oxygen change (that is, the oxygen consumption rate) in the microwells. We demonstrate the capability of this label-free technique by performing high-throughput single-cell oxygen-consumption-rate measurements of cultured cells and by imaging intratumoral metabolic heterogeneity in specimens from patients with breast cancer. High-throughput single-cell photoacoustic microscopy of oxygen consumption rates should enable the faster characterization of intratumoral metabolic heterogeneity.",
"doi": "10.1038/s41551-019-0376-5",
"pmcid": "PMC6544054",
"issn": "2157-846X",
"publisher": "Nature Publishing Group",
"publication": "Nature Biomedical Engineering",
"publication_date": "2019-05",
"series_number": "5",
"volume": "3",
"issue": "5",
"pages": "381-391"
},
{
"id": "authors:w8d78-6a816",
"collection": "authors",
"collection_id": "w8d78-6a816",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190403-091853231",
"type": "article",
"title": "In vivo superresolution photoacoustic computed tomography by localization of single dyed droplets",
"author": [
{
"family_name": "Zhang",
"given_name": "Pengfei",
"orcid": "0000-0002-4226-1394",
"clpid": "Zhang-Pengfei"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic (PA) computed tomography (PACT) is a noninvasive hybrid imaging technique that combines optical excitation and acoustic detection to realize high contrast, high resolution, and deep penetration in biological tissues. However, the spatial resolution of PACT is limited by acoustic diffraction. Here, we report in vivo superresolution PACT, which breaks the acoustic diffraction limit by localizing the centers of single dyed droplets that are flowing in blood vessels. The droplets were prepared by dissolving hydrophobic absorbing dye in oil, followed by mixing with water. The dyed droplets generate much higher-amplitude PA signals than blood and can flow smoothly in vessels; thus, they are excellent tracers for localization-based superresolution imaging. The in vivo resolution enhancement was demonstrated by continuously imaging the cortical layer of a mouse brain during droplet injection. The droplets that were flowing in the vessels were localized, and their center positions were used to construct a superresolution image that exhibits sharper features and more finely resolved vascular details. An improvement in spatial resolution by a factor of 6 has been realized in vivo by the droplet localization technique.",
"doi": "10.1038/s41377-019-0147-9",
"pmcid": "PMC6445830",
"issn": "2047-7538",
"publisher": "Nature Publishing Group",
"publication": "Light: Science & Applications",
"publication_date": "2019-04-03",
"volume": "8",
"pages": "Art. No. 36"
},
{
"id": "authors:1j3fe-8r879",
"collection": "authors",
"collection_id": "1j3fe-8r879",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190412-102929853",
"type": "article",
"title": "Dictionary learning sparse-sampling reconstruction method for in-vivo 3D photoacoustic computed tomography",
"author": [
{
"family_name": "Liu",
"given_name": "Fangyan",
"clpid": "Liu-Fangyan"
},
{
"family_name": "Gong",
"given_name": "Xiaojing",
"clpid": "Gong-Xiaojing"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Guan",
"given_name": "Jingjing",
"clpid": "Guan-Jingjing"
},
{
"family_name": "Song",
"given_name": "Liang",
"clpid": "Song-Liang"
},
{
"family_name": "Meng",
"given_name": "Jing",
"orcid": "0000-0002-9069-8988",
"clpid": "Meng-Jing"
}
],
"abstract": "The sparse transforms currently used in the model-based reconstruction method for photoacoustic computed tomography (PACT) are predefined and they typically cannot capture the underlying features of the specific data sets adequately, thus limiting the high-quality recovery of photoacoustic images. In this work, we present an advanced reconstruction model using the K-VSD dictionary learning technique and present the in vivo results after adapting the model into the 3D PACT system. The in vivo experiments were performed on an IRB approved human hand and two rats. When compared to the traditional sparse transform, experimental results using our proposed method improved accuracy and contrast to noise ration of the reconstructed photoacoustic images, on average, by 3.7 and 1.8 times in the case of 50% sparse-sampling rate, respectively. We also compared the performance of our algorithm against other techniques, and imaging speed was 60% faster than other approaches. Our system would require sparse-transducer array and lower number of data acquisition hardware (DAQs) potentially reducing the cost of the system. Thus, our work provides a new way for reconstructing photoacoustic images, and it would enable the development of new high-speed low-cost 3D PACT for various biomedical applications.",
"doi": "10.1364/boe.10.001660",
"pmcid": "PMC6484974",
"issn": "2156-7085",
"publisher": "Optical Society of America",
"publication": "Biomedical Optics Express",
"publication_date": "2019-04-01",
"series_number": "4",
"volume": "10",
"issue": "4",
"pages": "1660-1677"
},
{
"id": "authors:y1n9b-2j659",
"collection": "authors",
"collection_id": "y1n9b-2j659",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190211-082851540",
"type": "article",
"title": "Microwave-induced thermoacoustic tomography through an adult human skull",
"author": [
{
"family_name": "Yan",
"given_name": "An",
"orcid": "0000-0002-4676-5442",
"clpid": "Yan-An"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Liu",
"given_name": "Changjun",
"orcid": "0000-0003-0079-6793",
"clpid": "Liu-Changjun"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Na",
"given_name": "Shuai",
"orcid": "0000-0003-2083-0047",
"clpid": "Na-Shuai"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Purpose: To demonstrate the feasibility of microwave\u2010induced thermoacoustic tomography (TAT) of adult human brain. \n\nMethods: We analyzed the electric field distribution radiated from an antenna to acquire homogeneous illumination. We first imaged the anatomical structures in a rat's trunk to validate the thermoacoustic contrast in vivo. We then imaged an agar cylinder through an adult human skull ex vivo to demonstrate transcranial penetration of both microwave and ultrasound. We also analyzed the specific absorption rate to show the conformance to the safety standard for human electromagnetic exposure. \n\nResults: We successfully acquired cross\u2010sectional images of the rat's trunk in vivo. Major blood vessels and organs are clearly visible. The transcranial image shows that TAT can image through the adult human skull and reveal an agar enclosed by the skull. \n\nConclusions: Microwave\u2010induced TAT of a rat's trunk in vivo and an agar phantom through an adult human skull ex vivo has been demonstrated experimentally. This study demonstrates both the TAT contrasts in vivo and the capability of transcranial imaging, showing potential of TAT for adult human brain imaging with high contrast and penetration.",
"doi": "10.1002/mp.13439",
"pmcid": "PMC6453731",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2019-04",
"series_number": "4",
"volume": "46",
"issue": "4",
"pages": "1793-1797"
},
{
"id": "authors:gv9sb-esw92",
"collection": "authors",
"collection_id": "gv9sb-esw92",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190304-152755762",
"type": "article",
"title": "Angular-spectrum modeling of focusing light inside scattering media by optical phase conjugation",
"author": [
{
"family_name": "Yang",
"given_name": "Jiamiao",
"orcid": "0000-0003-0006-8411",
"clpid": "Yang-Jiamiao"
},
{
"family_name": "Li",
"given_name": "Jingwei",
"orcid": "0000-0003-4927-1066",
"clpid": "Li-Jingwei"
},
{
"family_name": "He",
"given_name": "Sailing",
"orcid": "0000-0002-3401-1125",
"clpid": "He-Sailing"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Focusing light inside scattering media by optical phase conjugation has been intensively investigated due to its potential applications, such as in deep tissue imaging. However, no existing physical models explain the impact of the various factors on the focusing performance inside a dynamic scattering medium. Here, we establish an angular-spectrum model to trace the field propagation during the entire optical phase conjugation process in the presence of scattering media. By incorporating fast decorrelation components, the model enables us to investigate the competition between the guide star and fast tissue motions for photon tagging. Other factors affecting the focusing performance are also analyzed via the model. As a proof of concept, we experimentally verify our model in the case of focusing light through dynamic scattering media. This angular-spectrum model allows analysis of a series of scattering events in highly scattering media and benefits related applications.",
"doi": "10.1364/optica.6.000250",
"pmcid": "PMC7002031",
"issn": "2334-2536",
"publisher": "Optical Society of America",
"publication": "Optica",
"publication_date": "2019-03-20",
"series_number": "3",
"volume": "6",
"issue": "3",
"pages": "250-256"
},
{
"id": "authors:j02yj-1xg82",
"collection": "authors",
"collection_id": "j02yj-1xg82",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180904-144102938",
"type": "article",
"title": "High-speed alignment optimization of digital optical phase conjugation systems based on autocovariance analysis in conjunction with orthonormal rectangular polynomials",
"author": [
{
"family_name": "Hemphill",
"given_name": "Ashton S.",
"clpid": "Hemphill-A-S"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Hwang",
"given_name": "Jeeseong",
"clpid": "Hwang-Jeeseong"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Digital optical phase conjugation (DOPC) enables many optical applications by permitting focusing of light through scattering media. However, DOPC systems require precise alignment of all optical components, particularly of the spatial light modulator (SLM) and camera, in order to accurately record the wavefront and perform playback through the use of time-reversal symmetry. We present a digital compensation technique to optimize the alignment of the SLM in five degrees of freedom, permitting focusing through thick scattering media with a thickness of 5 mm and transport scattering coefficient of 2.5\u2009\u2009mm\u2009\u2009\u2212\u2009\u20091 while simultaneously improving focal quality, as quantified by the peak-to-background ratio, by several orders of magnitude over an unoptimized alignment.",
"doi": "10.1117/1.JBO.24.3.031004",
"pmcid": "PMC6444113",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2019-03",
"series_number": "3",
"volume": "24",
"issue": "3",
"pages": "Art. No. 031004"
},
{
"id": "authors:xdam8-jtt36",
"collection": "authors",
"collection_id": "xdam8-jtt36",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190214-071356352",
"type": "article",
"title": "Efficient two-photon excitation by photonic dimers",
"author": [
{
"family_name": "Zhou",
"given_name": "Yao",
"clpid": "Zhou-Yao"
},
{
"family_name": "Chen",
"given_name": "Zihao",
"clpid": "Chen-Zihao"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Shen",
"given_name": "Jung-Tsung",
"clpid": "Shen-Jung-Tsung"
}
],
"abstract": "In this Letter, we show that photonic dimers, the quantum mechanical bound states of two photons, enable efficient nonlinear two-photon excitation, primarily due to the Lorentzian energy anti-correlation and to the temporal proximity between the constituent photons. We analytically and numerically demonstrate the order-of-magnitude improvement of the excitation efficiency per photon by the photonic dimers over the ultrashort pulses from a laser. We further show that, owing to the high excitation efficiency, the two-photon transition rate by photonic dimers deviates from the well-known linear intensity dependence at low intensities. Possible approaches for generating the photonic dimers in semiconductor platforms are also investigated.",
"doi": "10.1364/ol.44.000475",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2019-02-01",
"series_number": "3",
"volume": "44",
"issue": "3",
"pages": "475-478"
},
{
"id": "authors:p03hw-6ke83",
"collection": "authors",
"collection_id": "p03hw-6ke83",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190225-080636756",
"type": "article",
"title": "Photoacoustic computed tomography of human extremities",
"author": [
{
"family_name": "Wray",
"given_name": "Parker",
"orcid": "0000-0003-3384-0826",
"clpid": "Wray-P-R"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present a method of imaging angiographic structures in human extremities, including hands, arms, legs, and feet, using a newly developed photoacoustic computed tomography (PACT) system. The system features deep penetration (1.8 cm in muscular tissues) with high spatial and temporal resolutions. A volumetric image is acquired within 5 to 15 s while each cross sectional image is acquired within 100\u2009\u2009\u03bcs. Therefore, we see no blurring from motion in the imaging plane. Longitudinal and latitudinal cross-sectional images of a healthy volunteer clearly show the vascular network of each appendage and highlight the system's ability to image major and minor vasculatures, without the use of an external contrast or ionizing radiation. We also track heartbeat-induced arterial movement at a two-dimensional frame rate of 10 Hz. This work substantiates the idea that PACT could be used as a noninvasive method for imaging human vasculatures.",
"doi": "10.1117/1.JBO.24.2.026003",
"pmcid": "PMC6380242",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2019-02",
"series_number": "2",
"volume": "24",
"issue": "2",
"pages": "Art. No. 026003"
},
{
"id": "authors:byb2v-nyw82",
"collection": "authors",
"collection_id": "byb2v-nyw82",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190103-133532728",
"type": "article",
"title": "Novel, sensor-based quantitative cervical elastography: objective quantification of cervical softness",
"author": [
{
"family_name": "Stout",
"given_name": "Molly",
"clpid": "Stout-M"
},
{
"family_name": "Zhao",
"given_name": "Peinan",
"clpid": "Zhao-Peinan"
},
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Qu",
"given_name": "Yuan",
"clpid": "Qu-Yuan"
},
{
"family_name": "Chubiz",
"given_name": "Jessica",
"clpid": "Chubiz-J"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Garcia",
"given_name": "Julio Isla",
"clpid": "Garcia-J-I"
},
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Macones",
"given_name": "George A.",
"clpid": "Macones-G-A"
},
{
"family_name": "Tuuli",
"given_name": "Methodius G.",
"clpid": "Tuuli-M-G"
}
],
"abstract": "Cervical ripening is a necessary physiologic phenomenon\nthat precedes all labor, both term and preterm. Tissue elastography works by applying pressure to tissue and measuring tissue displacement. It is quantified by Young's modulus, a ratio of pressure to displacement. The harder the tissue, the less displacement and the higher the Young's modulus. It is a promising technique for\nmeasuring cervical tissue stiffness to predict preterm birth, but to date has been semi-quantitative because the exact force applied to the cervix is difficult quantify. We aimed to develop a novel, fully-quantitative cervical elastography system to objectively quantify cervical tissue stiffness.",
"doi": "10.1016/j.ajog.2018.11.017",
"issn": "0002-9378",
"publisher": "Elsevier",
"publication": "American Journal of Obstetrics and Gynecology",
"publication_date": "2019-01",
"series_number": "1",
"volume": "220",
"issue": "1",
"pages": "S13"
},
{
"id": "authors:t8n5w-59b05",
"collection": "authors",
"collection_id": "t8n5w-59b05",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181210-123533934",
"type": "article",
"title": "In vivo characterization of connective tissue remodeling using infrared photoacoustic spectra",
"author": [
{
"family_name": "Qu",
"given_name": "Yuan",
"clpid": "Qu-Yuan"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Premature cervical remodeling is a critical precursor of spontaneous preterm birth, and the remodeling process is characterized by an increase in tissue hydration. Nevertheless, current clinical measurements of cervical remodeling are subjective and detect only late events, such as cervical effacement and dilation. Here, we present a photoacoustic endoscope that can quantify tissue hydration by measuring near-infrared cervical spectra. We quantify the water contents of tissue-mimicking hydrogel phantoms as an analog of cervical connective tissue. Applying this method to pregnant women in vivo, we observed an increase in the water content of the cervix throughout pregnancy. The application of this technique in maternal healthcare may advance our understanding of cervical remodeling and provide a sensitive method for predicting preterm birth.",
"doi": "10.1117/1.JBO.23.12.121621",
"pmcid": "PMC6318810",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2018-12",
"series_number": "12",
"volume": "23",
"issue": "12",
"pages": "Art. No. 121621"
},
{
"id": "authors:5xffe-srz57",
"collection": "authors",
"collection_id": "5xffe-srz57",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181210-124531840",
"type": "article",
"title": "Transvaginal fast-scanning optical-resolution photoacoustic endoscopy",
"author": [
{
"family_name": "Qu",
"given_name": "Yuan",
"clpid": "Qu-Yuan"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic endoscopy offers in vivo examination of the visceral tissue using endogenous contrast, but its typical B-scan rate is \u223c10\u2009\u2009Hz, restricted by the speed of the scanning unit and the laser pulse repetition rate. Here, we present a transvaginal fast-scanning optical-resolution photoacoustic endoscope with a 250-Hz B-scan rate over a 3-mm scanning range. Using this modality, we not only illustrated the morphological differences of vasculatures among the human ectocervix, uterine body, and sublingual mucosa but also showed the longitudinal and cross-sectional differences of cervical vasculatures in pregnant women. This technology is promising for screening the visceral pathological changes associated with angiogenesis.",
"doi": "10.1117/1.JBO.23.12.121617",
"pmcid": "PMC6279961",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2018-12",
"series_number": "12",
"volume": "23",
"issue": "12",
"pages": "Art. No. 121617"
},
{
"id": "authors:cb1r6-k8210",
"collection": "authors",
"collection_id": "cb1r6-k8210",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190102-135257118",
"type": "article",
"title": "Special Section Guest Editorial: Pioneer in Biomedical Optics: Introduction to the Special Section in Honor of Steven L. Jacques",
"author": [
{
"family_name": "Hielscher",
"given_name": "Andreas H.",
"clpid": "Hielscher-A-H"
},
{
"family_name": "Ramella-Roman",
"given_name": "Jessica",
"clpid": "Ramella-Roman-J"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "This guest editorial introduces the special section honoring Prof. Steven L. Jacques. \n\nWe present this special section of the Journal of Biomedical Optics in honor of Steven L. Jacques, PhD, a leading pioneer in the field of biomedical optics. In the late eighties, Steve was part of a small group of researchers from various disciplines who clearly saw the potential of light and optics for new approaches to medical diagnostics and treatment of various diseases. Since then the field has grown exponentially and biomedical optics has become an integral part in many medical disciplines. Through his work and many seminal contributions, Steve has actively shaped this development.",
"doi": "10.1117/1.jbo.23.12.121601",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2018-12",
"series_number": "12",
"volume": "23",
"issue": "12",
"pages": "Art. No. 121601"
},
{
"id": "authors:cj428-fh987",
"collection": "authors",
"collection_id": "cj428-fh987",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181003-105017264",
"type": "article",
"title": "Compressed ultrafast photography by multi-encoding imaging",
"author": [
{
"family_name": "Yang",
"given_name": "Chengshuai",
"clpid": "Yang-Chengshuai"
},
{
"family_name": "Qi",
"given_name": "Dalong",
"clpid": "Qi-Dalong"
},
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Wang",
"given_name": "Xing",
"clpid": "Wang-Xing"
},
{
"family_name": "Cao",
"given_name": "Fengyan",
"clpid": "Cao-Fengyan"
},
{
"family_name": "He",
"given_name": "Yilin",
"clpid": "He-Yilin"
},
{
"family_name": "Ouyang",
"given_name": "Xiaoping",
"clpid": "Ouyang-Xiaoping"
},
{
"family_name": "Zhu",
"given_name": "Baoqiang",
"clpid": "Zhu-Baoqiang"
},
{
"family_name": "Wen",
"given_name": "Wenlong",
"clpid": "Wen-Wenlong"
},
{
"family_name": "Jia",
"given_name": "Tianqing",
"clpid": "Jia-Tianqing"
},
{
"family_name": "Tian",
"given_name": "Jinshou",
"clpid": "Tian-Jinshou"
},
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Sun",
"given_name": "Zhenrong",
"clpid": "Sun-Zhenrong"
},
{
"family_name": "Zhang",
"given_name": "Shian",
"clpid": "Zhang-Shian"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Imaging ultrafast dynamic scenes has been long pursued by scientists. As a two-dimensional dynamic imaging technique, compressed ultrafast photography (CUP) provides the fastest receive-only camera to capture transient events. This technique is based on three-dimensional image reconstruction by combining streak imaging with compressed sensing (CS). However, the image quality and the frame rate of CUP are limited by the CS-based image reconstruction algorithms and the inherent temporal and spatial resolutions of the streak camera. Here, we report a new method to improve the temporal and spatial resolutions of CUP. Our numerical simulation and experimental verification show that by using a multi-encoding imaging method, both the image quality and the frame rate of CUP can be significantly improved beyond the intrinsic technical parameters. Importantly, the temporal resolution by our scheme can break the limitation of the streak camera. Therefore, this new technology has potential benefits in many applications that require the ultrafast dynamic scene image with high temporal and spatial resolutions.",
"doi": "10.1088/1612-202x/aae198",
"issn": "1612-2011",
"publisher": "IOP Publishing",
"publication": "Laser Physics Letters",
"publication_date": "2018-11",
"series_number": "11",
"volume": "15",
"issue": "11",
"pages": "Art. No. 116202"
},
{
"id": "authors:dtp1k-ccr96",
"collection": "authors",
"collection_id": "dtp1k-ccr96",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181102-111253854",
"type": "article",
"title": "Synthetic Bessel light needle for extended depth-of-field microscopy",
"author": [
{
"family_name": "Yang",
"given_name": "Jiamiao",
"orcid": "0000-0003-0006-8411",
"clpid": "Yang-Jiamiao"
},
{
"family_name": "Gong",
"given_name": "Lei",
"orcid": "0000-0002-0995-5781",
"clpid": "Gong-Lei"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "An ultra-long light needle is highly desired in optical microscopy for its ability to improve the lateral resolution over a large depth of field (DOF). However, its use in image acquisition usually relies on mechanical raster scanning, which compromises between imaging speed and stability and thereby restricts imaging performance. Here, we propose a synthetic Bessel light needle (SBLN) that can be generated and scanned digitally by complex field modulation using a digital micromirror device. In particular, the SBLN achieves a 45-fold improvement in DOF over its counterpart Gaussian focus. Further, we apply the SBLN to perform motionless two-dimensional and three-dimensional microscopic imaging, achieving both improved resolution and extended DOF. Our work is expected to open up opportunities for potential biomedical applications.",
"doi": "10.1063/1.5058163",
"pmcid": "PMC6214810",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2018-10-29",
"series_number": "18",
"volume": "113",
"issue": "18",
"pages": "Art. No. 181104"
},
{
"id": "authors:fnd2h-kd774",
"collection": "authors",
"collection_id": "fnd2h-kd774",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181101-114159377",
"type": "article",
"title": "Dual-view photoacoustic microscopy for quantitative cell nuclear imaging",
"author": [
{
"family_name": "Cai",
"given_name": "De",
"clpid": "Cai-De"
},
{
"family_name": "Wong",
"given_name": "Terence T. W.",
"orcid": "0000-0001-6399-758X",
"clpid": "Wong-Terence-T-W"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Chen",
"given_name": "Sung-Liang",
"orcid": "0000-0002-0572-5110",
"clpid": "Chen-Sung-Liang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging imaging modality for studying biological tissues. However, in conventional single-view OR-PAM, the lateral and axial resolutions\u2014determined optically and acoustically, respectively\u2014are highly anisotropic. In this Letter, we introduce dual-view OR-PAM to improve axial resolution, achieving three-dimensional (3D) resolution isotropy. We first use 0.5 \u03bcm polystyrene beads and carbon fibers to validate the resolution isotropy improvement. Imaging of mouse brain slices further demonstrates the improved resolution isotropy, revealing the 3D structure of cell nuclei in detail, which facilitates quantitative cell nuclear analysis.",
"doi": "10.1364/ol.43.004875",
"pmcid": "PMC6245540",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2018-10-15",
"series_number": "20",
"volume": "43",
"issue": "20",
"pages": "4875-4878"
},
{
"id": "authors:dab83-83f29",
"collection": "authors",
"collection_id": "dab83-83f29",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190226-142528507",
"type": "article",
"title": "Compressed 3D Image Information and Communication Security",
"author": [
{
"family_name": "Yang",
"given_name": "Chengshuai",
"clpid": "Yang-Chengshuai"
},
{
"family_name": "Ding",
"given_name": "Yuyang",
"clpid": "Ding-Yuyang"
},
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Cao",
"given_name": "Fengyan",
"clpid": "Cao-Fengyan"
},
{
"family_name": "Qi",
"given_name": "Dalong",
"clpid": "Qi-Dalong"
},
{
"family_name": "Jia",
"given_name": "Tianqing",
"clpid": "Jia-Tianqing"
},
{
"family_name": "Sun",
"given_name": "Zhenrong",
"clpid": "Sun-Zhenrong"
},
{
"family_name": "Zhang",
"given_name": "Shian",
"clpid": "Zhang-Shian"
},
{
"family_name": "Chen",
"given_name": "Wei",
"clpid": "Chen-Wei"
},
{
"family_name": "Yin",
"given_name": "Zhenqiang",
"clpid": "Yin-Zhenqiang"
},
{
"family_name": "Wang",
"given_name": "Shuang",
"clpid": "Wang-Shuang"
},
{
"family_name": "Han",
"given_name": "Zhengfu",
"clpid": "Han-Zhengfu"
},
{
"family_name": "Guo",
"given_name": "Guangcan",
"clpid": "Guo-Guangcan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Ensuring information and communication security in military messages, government instructions, scientific experiments, as well as in personal data processing, is critical. In this study, a new hybrid classical\u2013quantum cryptographic scheme to protect image information and communication security is developed by combining a quantum key distribution (QKD) and compressed sensing (CS). This method employs a QKD system to generate true random codes among the remote legitimate users and utilizes these random codes to encrypt and decrypt compressed 3D image information based on the CS algorithm. Therefore, this new technique can provide computational security in the image information transmission process by the encryption and decryption of CS algorithm, and the information and communication security can be evaluated in real time by monitoring the QKD system. Furthermore, this technique can directly transmit and reconstruct the compressed 3D image information based on the modified TwIST algorithm, and thus fewer random codes are required in QKD system, which can improve the information transmission bandwidth. Consequently, this technique not only provides a new application of a QKD system but also extends the CS\u2010based image reconstruction from 2D to 3D. This study may open a new opportunity in the field of information and security communication.",
"doi": "10.1002/qute.201800034",
"issn": "2511-9044",
"publisher": "Wiley",
"publication": "Advanced Quantum Technologies",
"publication_date": "2018-10",
"series_number": "2",
"volume": "1",
"issue": "2",
"pages": "Art. No. 1800034"
},
{
"id": "authors:96vf1-x7s25",
"collection": "authors",
"collection_id": "96vf1-x7s25",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181008-153617133",
"type": "article",
"title": "Single-shot ultrafast optical imaging",
"author": [
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Single-shot ultrafast optical imaging can capture two-dimensional transient scenes in the optical spectral range at \u2265100 million frames per second. This rapidly evolving field surpasses conventional pump-probe methods by possessing real-time imaging capability, which is indispensable for recording nonrepeatable and difficult-to-reproduce events and for understanding physical, chemical, and biological mechanisms. In this mini-review, we survey state-of-the-art single-shot ultrafast optical imaging comprehensively. Based on the illumination requirement, we categorized the field into active-detection and passive-detection domains. Depending on the specific image acquisition and reconstruction strategies, these two categories are further divided into a total of six subcategories. Under each subcategory, we describe operating principles, present representative cutting-edge techniques, with a particular emphasis on their methodology and applications, and discuss their advantages and challenges. Finally, we envision prospects for technical advancement in this field.",
"doi": "10.1364/OPTICA.5.001113",
"pmcid": "PMC6388706",
"issn": "2334-2536",
"publisher": "Optical Society of America",
"publication": "Optica",
"publication_date": "2018-09-20",
"series_number": "9",
"volume": "5",
"issue": "9",
"pages": "1113-1127"
},
{
"id": "authors:n2vwf-7ec02",
"collection": "authors",
"collection_id": "n2vwf-7ec02",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180921-082406528",
"type": "article",
"title": "Large field homogeneous illumination in microwave-induced thermoacoustic tomography based on a quasi-conical spiral antenna",
"author": [
{
"family_name": "Yan",
"given_name": "An",
"orcid": "0000-0002-4676-5442",
"clpid": "Yan-An"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Na",
"given_name": "Shuai",
"orcid": "0000-0003-2083-0047",
"clpid": "Na-Shuai"
},
{
"family_name": "Liu",
"given_name": "Changjun",
"orcid": "0000-0003-0079-6793",
"clpid": "Liu-Changjun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Conventional helical and horn antennas based on frequency selective surfaces have been used to provide microwave illumination in microwave-induced thermoacoustic tomography (TAT). However, the electromagnetic waves radiated from the conventional antennas are not circularly polarized and thus impair image quality. In addition, conventional antennas can provide uniform radiations only within a relatively small area and thus limit their clinical applications (e.g., breast imaging). To address these problems, we propose a quasi-conical log-spiral antenna for homogenous illumination over a large field. We theoretically and experimentally validated this approach. Tissue-mimicking phantoms were imaged. The antenna produced not only an electric field with a circular polarization but also a homogeneous illumination area with a 10\u2009cm diameter. Accordingly, our method has advanced TAT by improving microwave illumination.",
"doi": "10.1063/1.5043541",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2018-09-17",
"series_number": "12",
"volume": "113",
"issue": "12",
"pages": "Art. No. 123701"
},
{
"id": "authors:3r0qa-xwn04",
"collection": "authors",
"collection_id": "3r0qa-xwn04",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180808-104134798",
"type": "article",
"title": "Single-shot real-time femtosecond imaging of temporal focusing",
"author": [
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "While the concept of focusing usually applies to the spatial domain, it is equally applicable to the time domain. Real-time imaging of temporal focusing of single ultrashort laser pulses is of great significance in exploring the physics of the space\u2013time duality and finding diverse applications. The drastic changes in the width and intensity of an ultrashort laser pulse during temporal focusing impose a requirement for femtosecond-level exposure to capture the instantaneous light patterns generated in this exquisite phenomenon. Thus far, established ultrafast imaging techniques either struggle to reach the desired exposure time or require repeatable measurements. We have developed single-shot 10-trillion-frame-per-second compressed ultrafast photography (T-CUP), which passively captures dynamic events with 100-fs frame intervals in a single camera exposure. The synergy between compressed sensing and the Radon transformation empowers T-CUP to significantly reduce the number of projections needed for reconstructing a high-quality three-dimensional spatiotemporal datacube. As the only currently available real-time, passive imaging modality with a femtosecond exposure time, T-CUP was used to record the first-ever movie of non-repeatable temporal focusing of a single ultrashort laser pulse in a dynamic scattering medium. T-CUP's unprecedented ability to clearly reveal the complex evolution in the shape, intensity, and width of a temporally focused pulse in a single measurement paves the way for single-shot characterization of ultrashort pulses, experimental investigation of nonlinear light-matter interactions, and real-time wavefront engineering for deep-tissue light focusing.",
"doi": "10.1038/s41377-018-0044-7",
"pmcid": "PMC6107054",
"issn": "2047-7538",
"publisher": "Nature Publishing Group",
"publication": "Light: Science and Applications",
"publication_date": "2018-08-08",
"volume": "7",
"pages": "Art. No. 42"
},
{
"id": "authors:0f0hw-dj350",
"collection": "authors",
"collection_id": "0f0hw-dj350",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180409-102507871",
"type": "article",
"title": "Recent progress in photoacoustic molecular imaging",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "By acoustically detecting the optical absorption contrast, photoacoustic (PA) tomography (PAT) has broken the penetration limits of traditional high-resolution optical imaging. Through spectroscopic analysis of the target's optical absorption, PAT can identify a wealth of endogenous and exogenous molecules and thus is inherently capable of molecular imaging with high sensitivity. PAT's molecular sensitivity is uniquely accompanied by non-ionizing radiation, high spatial resolution, and deep penetration in biological tissues, which other optical imaging modalities cannot achieve yet. In this concise review, we summarize the most recent technological advancements in PA molecular imaging and highlight the novel molecular probes specifically made for PAT in deep tissues. We conclude with a brief discussion of the opportunities for future advancements.",
"doi": "10.1016/j.cbpa.2018.03.016",
"pmcid": "PMC6076847",
"issn": "1367-5931",
"publisher": "Elsevier",
"publication": "Current Opinion in Chemical Biology",
"publication_date": "2018-08",
"volume": "45",
"pages": "104-112"
},
{
"id": "authors:fden4-t1r86",
"collection": "authors",
"collection_id": "fden4-t1r86",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180716-093756630",
"type": "article",
"title": "Small near-infrared photochromic protein for photoacoustic multi-contrast imaging and detection of protein interactions in vivo",
"author": [
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Shemetov",
"given_name": "Anton A.",
"clpid": "Shemetov-Anton-A"
},
{
"family_name": "Baloban",
"given_name": "Mikhail",
"clpid": "Baloban-Mikhail"
},
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Shcherbakova",
"given_name": "Daria M.",
"orcid": "0000-0003-3384-6363",
"clpid": "Shcherbakova-Daria-M"
},
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Verkhusha",
"given_name": "Vladislav V.",
"orcid": "0000-0002-2083-8121",
"clpid": "Verkhusha-Vladislav-V"
}
],
"abstract": "Photoacoustic (PA) computed tomography (PACT) benefits from genetically encoded probes with photochromic behavior, which dramatically increase detection sensitivity and specificity through photoswitching and differential imaging. Starting with a DrBphP bacterial phytochrome, we have engineered a near-infrared photochromic probe, DrBphP-PCM, which is superior to the full-length RpBphP1 phytochrome previously used in differential PACT. DrBphP-PCM has a smaller size, better folding, and higher photoswitching contrast. We have imaged both DrBphP-PCM and RpBphP1 simultaneously on the basis of their unique signal decay characteristics, using a reversibly switchable single-impulse panoramic PACT (RS-SIP-PACT) with a single wavelength excitation. The simple structural organization of DrBphP-PCM allows engineering a bimolecular PA complementation reporter, a split version of DrBphP-PCM, termed DrSplit. DrSplit enables PA detection of protein\u2013protein interactions in deep-seated mouse tumors and livers, achieving 125-\u00b5m spatial resolution and 530-cell sensitivity in vivo. The combination of RS-SIP-PACT with DrBphP-PCM and DrSplit holds great potential for noninvasive multi-contrast deep-tissue functional imaging.",
"doi": "10.1038/s41467-018-05231-3",
"pmcid": "PMC6048155",
"issn": "2041-1723",
"publisher": "Nature Publishing Group",
"publication": "Nature Communications",
"publication_date": "2018-07-16",
"volume": "9",
"pages": "Art. No. 2734"
},
{
"id": "authors:wjdtb-5bd61",
"collection": "authors",
"collection_id": "wjdtb-5bd61",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180716-103911158",
"type": "article",
"title": "Dual-axis illumination for virtually augmenting the detection view of optical-resolution photoacoustic microscopy",
"author": [
{
"family_name": "Hsu",
"given_name": "Hsun-Chia",
"clpid": "Hsu-Hsun-Chia"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wong",
"given_name": "Terence T. W.",
"orcid": "0000-0001-6399-758X",
"clpid": "Wong-Terence-T-W"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical-resolution photoacoustic microscopy (OR-PAM) has demonstrated fast, label-free volumetric imaging of optical-absorption contrast within the quasiballistic regime of photon scattering. However, the limited numerical aperture of the ultrasonic transducer restricts the detectability of the photoacoustic waves, thus resulting in incomplete reconstructed features. To tackle the limited-view problem, we added an oblique illumination beam to the original coaxial optical-acoustic scheme to provide a complementary detection view. The virtual augmentation of the detection view was validated through numerical simulations and tissue-phantom experiments. More importantly, the combination of top and oblique illumination successfully imaged a mouse brain in vivo down to 1\u00a0mm in depth, showing detailed brain vasculature. Of special note, it clearly revealed the diving vessels that were long missing in images from original OR-PAM.",
"doi": "10.1117/1.JBO.23.7.076001",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2018-07",
"series_number": "7",
"volume": "23",
"issue": "7",
"pages": "Art. No. 076001"
},
{
"id": "authors:z16qg-pd091",
"collection": "authors",
"collection_id": "z16qg-pd091",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180615-093451514",
"type": "article",
"title": "Single-breath-hold photoacoustic computed tomography of the breast",
"author": [
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Appleton",
"given_name": "Catherine M.",
"orcid": "0000-0002-6622-3667",
"clpid": "Appleton-Catherine-M"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-Konstantin-I"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have developed a single-breath-hold photoacoustic computed tomography (SBH-PACT) system to reveal detailed angiographic structures in human breasts. SBH-PACT features a deep penetration depth (4\u2009cm in vivo) with high spatial and temporal resolutions (255\u2009\u00b5m in-plane resolution and a 10\u2009Hz 2D frame rate). By scanning the entire breast within a single breath hold (~15\u2009s), a volumetric image can be acquired and subsequently reconstructed utilizing 3D back-projection with negligible breathing-induced motion artifacts. SBH-PACT clearly reveals tumors by observing higher blood vessel densities associated with tumors at high spatial resolution, showing early promise for high sensitivity in radiographically dense breasts. In addition to blood vessel imaging, the high imaging speed enables dynamic studies, such as photoacoustic elastography, which identifies tumors by showing less compliance. We imaged breast cancer patients with breast sizes ranging from B cup to DD cup, and skin pigmentations ranging from light to dark. SBH-PACT identified all the tumors without resorting to ionizing radiation or exogenous contrast, posing no health risks.",
"doi": "10.1038/s41467-018-04576-z",
"pmcid": "PMC6003984",
"issn": "2041-1723",
"publisher": "Nature Publishing Group",
"publication": "Nature Communications",
"publication_date": "2018-06-15",
"volume": "9",
"pages": "Art. No. 2352"
},
{
"id": "authors:n86z9-r5r82",
"collection": "authors",
"collection_id": "n86z9-r5r82",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180718-150844817",
"type": "article",
"title": "Parameterized Joint Reconstruction of the Initial Pressure and Sound Speed Distributions for Photoacoustic Computed Tomography",
"author": [
{
"family_name": "Matthews",
"given_name": "Thomas P.",
"orcid": "0000-0002-9365-6812",
"clpid": "Matthews-Thomas-P"
},
{
"family_name": "Poudel",
"given_name": "Joemini",
"clpid": "Poudel-Joemini"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-Mark-A"
}
],
"abstract": "Accurate estimation of the initial pressure distribution in photoacoustic computed tomography (PACT) depends on knowledge of the sound speed distribution. However, the sound speed distribution is typically unknown. Further, the initial pressure and sound speed distributions cannot both, in general, be stably recovered from PACT measurements alone. In this work, a joint reconstruction (JR) method for the initial pressure distribution and a low-dimensional parameterized model of the sound speed distribution is proposed. By employing a priori information about the structure of the sound speed distribution, both the initial pressure and sound speed can be accurately recovered. The JR problem is solved by use of a proximal optimization method that allows constraints and nonsmooth regularization functions for the initial pressure distribution. The gradients of the cost function with respect to the initial pressure and sound speed distributions are calculated by use of an adjoint state method that has the same per-iteration computational cost as calculating the gradient with respect to the initial pressure distribution alone. This approach is evaluated through two-dimensional computer-simulation studies for a small animal imaging model and by application to experimental in vivo measurements of a mouse.",
"doi": "10.1137/17M1153649",
"pmcid": "PMC6447310",
"issn": "1936-4954",
"publisher": "SIAM",
"publication": "SIAM Journal on Imaging Sciences",
"publication_date": "2018-06-05",
"series_number": "2",
"volume": "11",
"issue": "2",
"pages": "1560-1588"
},
{
"id": "authors:trab1-tz038",
"collection": "authors",
"collection_id": "trab1-tz038",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180530-095302605",
"type": "article",
"title": "Label-free high-throughput photoacoustic imaging of circulating melanoma tumor cells in patients in vivo",
"author": [
{
"family_name": "Hai",
"given_name": "P.",
"clpid": "Hai-P"
},
{
"family_name": "Shmuylovich",
"given_name": "L.",
"clpid": "Shmuylovich-L"
},
{
"family_name": "Qu",
"given_name": "Y.",
"clpid": "Qu-Y"
},
{
"family_name": "Cornelius",
"given_name": "L. A.",
"clpid": "Cornelius-L-A"
},
{
"family_name": "Wang",
"given_name": "L.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "[no abstract]",
"doi": "10.1016/j.jid.2018.03.1219",
"issn": "0022-202X",
"publisher": "Elsevier",
"publication": "Journal of Investigative Dermatology",
"publication_date": "2018-05",
"series_number": "5",
"volume": "138",
"issue": "5",
"pages": "S204"
},
{
"id": "authors:1hn1c-rmj35",
"collection": "authors",
"collection_id": "1hn1c-rmj35",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190304-152755895",
"type": "article",
"title": "Multiscale Photoacoustic Tomography",
"author": [
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography can bridge microscopic insights and macroscopic observations, providing imaging over a range of spatial scales\u2014from organelles and cells to tissues, small animals and human organs.",
"doi": "10.1364/opn.29.4.000032",
"issn": "1047-6938",
"publisher": "Optical Society of America",
"publication": "Optics and Photonics News",
"publication_date": "2018-04",
"series_number": "4",
"volume": "29",
"issue": "4",
"pages": "32-39"
},
{
"id": "authors:zdyjc-z3b39",
"collection": "authors",
"collection_id": "zdyjc-z3b39",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180509-110938282",
"type": "article",
"title": "Dichroism-sensitive photoacoustic computed tomography",
"author": [
{
"family_name": "Qu",
"given_name": "Yuan",
"clpid": "Qu-Yuan"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Wei",
"given_name": "Xiaoming",
"orcid": "0000-0001-6136-5335",
"clpid": "Wei-Xiaoming"
},
{
"family_name": "Wong",
"given_name": "Terence T. W.",
"orcid": "0000-0001-6399-758X",
"clpid": "Wong-Terence-T-W"
},
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-Konstantin-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic computed tomography (PACT), a fast-developing modality for deep tissue imaging, images the spatial distribution of optical absorption. PACT usually treats the absorption coefficient as a scalar. However, the absorption coefficients of many biological tissues exhibit an anisotropic property, known as dichroism or diattenuation, which depends on molecular conformation and structural alignment. Here, we present a novel imaging method called dichroism-sensitive PACT (DS-PACT), which measures both the amplitude of tissue's dichroism and the orientation of the optic axis of uniaxial dichroic tissue. By modulating the polarization of linearly polarized light and measuring the alternating signals through lock-in detection, DS-PACT can boost dichroic signals from biological tissues. To validate the proposed approach, we experimentally demonstrated the performance of DS-PACT by imaging plastic polarizers and ex vivo bovine tendons deep inside scattering media. We successfully detected the orientation of the optic axis of uniaxial dichroic materials, even at a depth of 4.5 transport mean free paths. We anticipate that the proposed method will extend the capability of PACT to imaging tissue absorption anisotropy.",
"doi": "10.1364/OPTICA.5.000495",
"pmcid": "PMC6388697",
"issn": "2334-2536",
"publisher": "Optical Society of America",
"publication": "Optica",
"publication_date": "2018-04",
"series_number": "4",
"volume": "5",
"issue": "4",
"pages": "495-501"
},
{
"id": "authors:xhdhk-b2b06",
"collection": "authors",
"collection_id": "xhdhk-b2b06",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180319-130354510",
"type": "article",
"title": "High-throughput ultraviolet photoacoustic microscopy with multifocal excitation",
"author": [
{
"family_name": "Imai",
"given_name": "Toru",
"orcid": "0000-0002-9497-8549",
"clpid": "Imai-Toru"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Wong",
"given_name": "Terence T. W.",
"orcid": "0000-0001-6399-758X",
"clpid": "Wong-Terence-T-W"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Ultraviolet photoacoustic microscopy (UV-PAM) is a promising intraoperative tool for surgical margin assessment (SMA), one that can provide label-free histology-like images with high resolution. In this study, using a microlens array and a one-dimensional (1-D) array ultrasonic transducer, we developed a high-throughput multifocal UV-PAM (MF-UV-PAM). Our new system achieved a 1.6\u2009\u2009\u00b1\u2009\u20090.2\u2009\u2009\u03bcm lateral resolution and produced images 40 times faster than the previously developed point-by-point scanning UV-PAM. MF-UV-PAM provided a readily comprehensible photoacoustic image of a mouse brain slice with specific absorption contrast in \u223c16\u2009\u2009min, highlighting cell nuclei. Individual cell nuclei could be clearly resolved, showing its practical potential for intraoperative SMA.",
"doi": "10.1117/1.JBO.23.3.036007",
"pmcid": "PMC5852316",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2018-03",
"series_number": "3",
"volume": "23",
"issue": "3",
"pages": "Art. No. 036007"
},
{
"id": "authors:d9y4v-pe853",
"collection": "authors",
"collection_id": "d9y4v-pe853",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180307-130604402",
"type": "article",
"title": "Optimizing codes for compressed ultrafast photography by the genetic algorithm",
"author": [
{
"family_name": "Yang",
"given_name": "Chengshuai",
"clpid": "Yang-Chengshuai"
},
{
"family_name": "Qi",
"given_name": "Dalong",
"clpid": "Qi-Dalong"
},
{
"family_name": "Wang",
"given_name": "Xing",
"clpid": "Wang-Xing"
},
{
"family_name": "Cao",
"given_name": "Fengyan",
"clpid": "Cao-Fengyan"
},
{
"family_name": "He",
"given_name": "Yilin",
"clpid": "He-Yilin"
},
{
"family_name": "Wen",
"given_name": "Wenlong",
"clpid": "Wen-Wenlong"
},
{
"family_name": "Jia",
"given_name": "Tianqing",
"clpid": "Jia-Tianqing"
},
{
"family_name": "Tian",
"given_name": "Jinshou",
"clpid": "Tian-Jinshou"
},
{
"family_name": "Sun",
"given_name": "Zhenrong",
"clpid": "Sun-Zhenrong"
},
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Zhang",
"given_name": "Shian",
"clpid": "Zhang-Shian"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The compressed ultrafast photography (CUP) technique, providing the fastest receive-only camera so far, has shown to be a well-established tool to capture the ultrafast dynamical scene. This technique is based on random codes to encode and decode the ultrafast dynamical scene by a compressed sensing algorithm. The choice of random codes significantly affects the image reconstruction quality. Therefore, it is important to optimize the encoding codes. Here, we develop a new scheme to obtain the optimized codes by combining a genetic algorithm (GA) into the CUP technique. First, we measure the dynamical scene by the CUP system with random codes and obtain the dynamical scene image at each moment. Second, we use these reconstructed dynamical scene images as the optimization target and optimize the encoding codes based on the GA. Finally, we utilize the optimized codes to recapture the dynamical scene and improve the image reconstruction quality. We validate our optimization scheme by the numerical simulation of a moving double-semielliptical spot and the experimental demonstration of a time- and space-evolving pulsed laser spot.",
"doi": "10.1364/OPTICA.5.000147",
"issn": "2334-2536",
"publisher": "Optical Society of America",
"publication": "Optica",
"publication_date": "2018-02-20",
"series_number": "2",
"volume": "5",
"issue": "2",
"pages": "147-151"
},
{
"id": "authors:900jn-zfe36",
"collection": "authors",
"collection_id": "900jn-zfe36",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180307-130605286",
"type": "article",
"title": "Label-free cell nuclear imaging by Gr\u00fcneisen relaxation photoacoustic microscopy",
"author": [
{
"family_name": "Liu",
"given_name": "Xiaowei",
"clpid": "Liu-Xiaowei"
},
{
"family_name": "Wong",
"given_name": "Terence T. W.",
"orcid": "0000-0001-6399-758X",
"clpid": "Wong-Terence-T-W"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Ma",
"given_name": "Jun",
"clpid": "Ma-Jun"
},
{
"family_name": "Yang",
"given_name": "Qing",
"clpid": "Yang-Qing"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic microscopy (PAM) with ultraviolet (UV) laser illumination has recently been demonstrated as a promising tool that provides fast, label-free, and multilayered histologic imaging of human breast tissue. Thus far, the axial resolution has been determined ultrasonically. To enable optically defined axial resolution, we exploit the Gr\u00fcneisen relaxation (GR) effect. By imaging mouse brain slices, we show that GRUV-PAM reveals detailed information about three-dimensional cell nuclear distributions and internal structures, which are important diagnostic features for cancers. Due to the nonlinear effect, GRUV-PAM also provides better contrast in images of cell nuclei.",
"doi": "10.1364/OL.43.000947",
"pmcid": "PMC5839111",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2018-02-15",
"series_number": "4",
"volume": "43",
"issue": "4",
"pages": "947-950"
},
{
"id": "authors:raezb-xd476",
"collection": "authors",
"collection_id": "raezb-xd476",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171004-083525247",
"type": "article",
"title": "Correcting the limited view in optical-resolution photoacoustic microscopy",
"author": [
{
"family_name": "Liu",
"given_name": "Wei",
"orcid": "0000-0002-1727-6738",
"clpid": "Liu-Wei-BiomedEng"
},
{
"family_name": "Zhou",
"given_name": "Yuan",
"clpid": "Zhou-Yuan"
},
{
"family_name": "Wang",
"given_name": "Mengran",
"clpid": "Wang-Mengran"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Vienneau",
"given_name": "Emelina",
"clpid": "Vienneau-E"
},
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "Luo",
"given_name": "Jianwen",
"clpid": "Luo-Jianwen"
},
{
"family_name": "Xu",
"given_name": "Chris",
"clpid": "Xu-Chris"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
}
],
"abstract": "Optical-resolution photoacoustic microscopy (OR-PAM) has proven useful for anatomical and functional imaging with high spatial resolutions. However, the coherent signal generation and the desired reflection-mode detection in OR-PAM can result in a limited detectability of features aligned with the acoustic axis (i.e., vertical structures). Here, we investigated the limited-view phenomenon in OR-PAM by simulating the generation and propagation of the acoustic pressure waves and determined the key optical parameters affecting the visibility of vertical structures. Proof-of-concept numerical experiments were performed with different illumination angles, optical foci, and numerical apertures (NA) of the objective lens. The results collectively show that an NA of 0.3 can readily improve the visibility of vertical structures in a typical reflection-mode OR-PAM system. This conclusion was confirmed by numerical simulations on the cortical blood vessels in a mouse brain, and by experiments in a suture-cross phantom and in a mouse brain in vivo.",
"doi": "10.1002/jbio.201700196",
"issn": "1864-063X",
"publisher": "Wiley",
"publication": "Journal of Biophotonics",
"publication_date": "2018-02",
"series_number": "2",
"volume": "11",
"issue": "2",
"pages": "Art. No. e201700196"
},
{
"id": "authors:yj78y-q2689",
"collection": "authors",
"collection_id": "yj78y-q2689",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170627-080108636",
"type": "article",
"title": "High-resolution deep functional imaging of the whole mouse brain by photoacoustic computed tomography in vivo",
"author": [
{
"family_name": "Zhang",
"given_name": "Pengfei",
"clpid": "Zhang-Pengfei"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Hu",
"given_name": "Peng",
"orcid": "0000-0002-2933-1239",
"clpid": "Hu-Peng"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "He",
"given_name": "Yun",
"orcid": "0000-0001-8430-6370",
"clpid": "He-Yun"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic computed tomography (PACT) is a non-invasive imaging technique offering high contrast, high resolution, and deep penetration in biological tissues. We report a PACT system equipped with a high frequency linear transducer array for mapping the microvascular network of a whole mouse brain with the skull intact and studying its hemodynamic activities. The linear array was scanned in the coronal plane to collect data from different angles, and full-view images were synthesized from the limited-view images in which vessels were only partially revealed. We investigated spontaneous neural activities in the deep brain by monitoring the concentration of hemoglobin in the blood vessels and observed strong interhemispherical correlations between several chosen functional regions, both in the cortical layer and in the deep regions. We also studied neural activities during an epileptic seizure and observed the epileptic wave spreading around the injection site and the wave propagating in the opposite hemisphere.",
"doi": "10.1002/jbio.201700024",
"pmcid": "PMC5777675",
"issn": "1864-063X",
"publisher": "Wiley",
"publication": "Journal of Biophotonics",
"publication_date": "2018-01",
"series_number": "1",
"volume": "11",
"issue": "1",
"pages": "Art. No. e201700024"
},
{
"id": "authors:ftewx-prw03",
"collection": "authors",
"collection_id": "ftewx-prw03",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180116-102559459",
"type": "article",
"title": "Time-reversed ultrasonically encoded optical focusing through highly scattering ex vivo human cataractous lenses",
"author": [
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Ruan",
"given_name": "Haowen",
"orcid": "0000-0002-4917-4509",
"clpid": "Ruan-Haowen"
},
{
"family_name": "Brodie",
"given_name": "Frank L.",
"clpid": "Brodie-F-L"
},
{
"family_name": "Wong",
"given_name": "Terence T. W.",
"orcid": "0000-0001-6399-758X",
"clpid": "Wong-Terence-T-W"
},
{
"family_name": "Yang",
"given_name": "Changhuei",
"orcid": "0000-0001-8791-0354",
"clpid": "Yang-Changhuei"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Normal development of the visual system in infants relies on clear images being projected onto the retina, which can be disrupted by lens opacity caused by congenital cataract. This disruption, if uncorrected in early life, results in amblyopia (permanently decreased vision even after removal of the cataract). Doctors are able to prevent amblyopia by removing the cataract during the first several weeks of life, but this surgery risks a host of complications, which can be equally visually disabling. Here, we investigated the feasibility of focusing light noninvasively through highly scattering cataractous lenses to stimulate the retina, thereby preventing amblyopia. This approach would allow the cataractous lens removal surgery to be delayed and hence greatly reduce the risk of complications from early surgery. Employing a wavefront shaping technique named time-reversed ultrasonically encoded optical focusing in reflection mode, we focused 532-nm light through a highly scattering ex vivo adult human cataractous lens. This work demonstrates a potential clinical application of wavefront shaping techniques.",
"doi": "10.1117/1.JBO.23.1.010501",
"pmcid": "PMC5762002",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2018-01",
"series_number": "1",
"volume": "23",
"issue": "1",
"pages": "Art. No. 010501"
},
{
"id": "authors:4ag2k-x1t13",
"collection": "authors",
"collection_id": "4ag2k-x1t13",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180118-145948329",
"type": "article",
"title": "A Forward-Adjoint Operator Pair Based on the Elastic Wave Equation for Use in Transcranial Photoacoustic Computed Tomography",
"author": [
{
"family_name": "Mitsuhashi",
"given_name": "Kenji",
"clpid": "Mitsuhashi-Kenji"
},
{
"family_name": "Poudel",
"given_name": "Joemini",
"clpid": "Poudel-J"
},
{
"family_name": "Matthews",
"given_name": "Thomas P.",
"clpid": "Matthews-T-P"
},
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
}
],
"abstract": "Photoacoustic computed tomography (PACT) is an emerging imaging modality that exploits optical contrast and ultrasonic detection principles to form images of the photoacoustically induced initial pressure distribution within tissue. The PACT reconstruction problem corresponds to an inverse source problem in which the initial pressure distribution is recovered from measurements of the radiated wavefield. A major challenge in transcranial PACT brain imaging is compensation for aberrations in the measured data due to the presence of the skull. Ultrasonic waves undergo absorption, scattering, and longitudinal-to-shear wave mode conversion as they propagate through the skull. To properly account for these effects, a wave-equation-based inversion method should be employed that can model the heterogeneous elastic properties of the skull. In this work, a forward model based on a finite-difference time-domain discretization of the three-dimensional elastic wave equation is established and a procedure for computing the corresponding adjoint of the forward operator is presented. Massively parallel implementations of these operators employing multiple graphics processing units are also developed. The developed numerical framework is validated and investigated in computer-simulation and experimental phantom studies whose designs are motivated by transcranial PACT applications.",
"doi": "10.1137/16M1107619",
"pmcid": "PMC5788322",
"issn": "1936-4954",
"publisher": "SIAM",
"publication": "SIAM Journal on Imaging Sciences",
"publication_date": "2017-11-16",
"series_number": "4",
"volume": "10",
"issue": "4",
"pages": "2022-2048"
},
{
"id": "authors:0vgyh-cyt78",
"collection": "authors",
"collection_id": "0vgyh-cyt78",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171122-080140092",
"type": "article",
"title": "Focusing light through scattering media by polarization modulation based generalized digital optical phase conjugation",
"author": [
{
"family_name": "Yang",
"given_name": "Jiamiao",
"orcid": "0000-0003-0006-8411",
"clpid": "Yang-Jiamiao"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Hemphill",
"given_name": "Ashton S.",
"clpid": "Hemphill-Ashton-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical scattering prevents light from being focused through thick biological tissue at depths greater than \u223c1\u2009mm. To break this optical diffusion limit, digital optical phase conjugation (DOPC) based wavefront shaping techniques are being actively developed. Previous DOPC systems employed spatial light modulators that modulated either the phase or the amplitude of the conjugate light field. Here, we achieve optical focusing through scattering media by using polarization modulation based generalized DOPC. First, we describe an algorithm to extract the polarization map from the measured scattered field. Then, we validate the algorithm through numerical simulations and find that the focusing contrast achieved by polarization modulation is similar to that achieved by phase modulation. Finally, we build a system using an inexpensive twisted nematic liquid crystal based spatial light modulator (SLM) and experimentally demonstrate light focusing through 3-mm thick chicken breast tissue. Since the polarization modulation based SLMs are widely used in displays and are having more and more pixel counts with the prevalence of 4\u2009K displays, these SLMs are inexpensive and valuable devices for wavefront shaping.",
"doi": "10.1063/1.5005831",
"pmcid": "PMC5690666",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2017-11-13",
"series_number": "20",
"volume": "111",
"issue": "20",
"pages": "Art. No. 201108"
},
{
"id": "authors:qvt6d-gw929",
"collection": "authors",
"collection_id": "qvt6d-gw929",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171113-084411285",
"type": "article",
"title": "Label-free automated three-dimensional imaging of whole organs by microtomy-assisted photoacoustic microscopy",
"author": [
{
"family_name": "Wong",
"given_name": "Terence T. W.",
"orcid": "0000-0001-6399-758X",
"clpid": "Wong-Terence-T-W"
},
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Hsu",
"given_name": "Hsun-Chia",
"clpid": "Hsu-Hsun-Chia"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-Konstantin-I"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"orcid": "0000-0003-1527-3020",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Three-dimensional (3D) optical imaging of whole biological organs with microscopic resolution has remained a challenge. Most versions of such imaging techniques require special preparation of the tissue specimen. Here we demonstrate microtomy-assisted photoacoustic microscopy (mPAM) of mouse brains and other organs, which automatically acquires serial distortion-free and registration-free images with endogenous absorption contrasts. Without tissue staining or clearing, mPAM generates micrometer-resolution 3D images of paraffin- or agarose-embedded whole organs with high fidelity, achieved by label-free simultaneous sensing of DNA/RNA, hemoglobins, and lipids. mPAM provides histology-like imaging of cell nuclei, blood vessels, axons, and other anatomical structures, enabling the application of histopathological interpretation at the organelle level to analyze a whole organ. Its deep tissue imaging capability leads to less sectioning, resulting in negligible sectioning artifact. mPAM offers a new way to better understand complex biological organs.",
"doi": "10.1038/s41467-017-01649-3",
"pmcid": "PMC5680318",
"issn": "2041-1723",
"publisher": "Nature Publishing Group",
"publication": "Nature Communications",
"publication_date": "2017-11-09",
"volume": "8",
"pages": "Art. No. 1386"
},
{
"id": "authors:53nkx-q1113",
"collection": "authors",
"collection_id": "53nkx-q1113",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171130-090421392",
"type": "article",
"title": "High-speed single-shot optical focusing through dynamic scattering media with full-phase wavefront shaping",
"author": [
{
"family_name": "Hemphill",
"given_name": "Ashton S.",
"clpid": "Hemphill-Ashton-S"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In biological applications, optical focusing is limited by the diffusion of light, which prevents focusing at depths greater than \u223c1\u2009mm in soft tissue. Wavefront shaping extends the depth by compensating for phase distortions induced by scattering and thus allows for focusing light through biological tissue beyond the optical diffusion limit by using constructive interference. However, due to physiological motion, light scattering in tissue is deterministic only within a brief speckle correlation time. In in vivo tissue, this speckle correlation time is on the order of milliseconds, and so the wavefront must be optimized within this brief period. The speed of digital wavefront shaping has typically been limited by the relatively long time required to measure and display the optimal phase pattern. This limitation stems from the low speeds of cameras, data transfer and processing, and spatial light modulators. While binary-phase modulation requiring only two images for the phase measurement has recently been reported, most techniques require at least three frames for the full-phase measurement. Here, we present a full-phase digital optical phase conjugation method based on off-axis holography for single-shot optical focusing through scattering media. By using off-axis holography in conjunction with graphics processing unit based processing, we take advantage of the single-shot full-phase measurement while using parallel computation to quickly reconstruct the phase map. With this system, we can focus light through scattering media with a system latency of approximately 9 ms, on the order of the in vivo speckle correlation time.",
"doi": "10.1063/1.5009113",
"pmcid": "PMC5709093",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2017-11",
"series_number": "22",
"volume": "111",
"issue": "22",
"pages": "Art. No. 221109"
},
{
"id": "authors:hj9s0-gja48",
"collection": "authors",
"collection_id": "hj9s0-gja48",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171003-132930006",
"type": "article",
"title": "Motionless volumetric photoacoustic microscopy with spatially invariant resolution",
"author": [
{
"family_name": "Yang",
"given_name": "Jiamiao",
"orcid": "0000-0003-0006-8411",
"clpid": "Yang-Jiamiao"
},
{
"family_name": "Gong",
"given_name": "Lei",
"orcid": "0000-0002-0995-5781",
"clpid": "Gong-Lei"
},
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Hai",
"given_name": "Pengfei",
"clpid": "Hai-Pengfei"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Suzuki",
"given_name": "Yuta",
"clpid": "Suzuki-Yuta"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic microscopy (PAM) is uniquely positioned for biomedical applications because of its ability to visualize optical absorption contrast in vivo in three dimensions. Here we propose motionless volumetric spatially invariant resolution photoacoustic microscopy (SIR-PAM). To realize motionless volumetric imaging, SIR-PAM combines two-dimensional Fourier-spectrum optical excitation with single-element depth-resolved photoacoustic detection. To achieve spatially invariant lateral resolution, propagation-invariant sinusoidal fringes are generated by a digital micromirror device. Further, SIR-PAM achieves 1.5 times finer lateral resolution than conventional PAM. The superior performance was demonstrated in imaging both inanimate objects and animals in vivo with a resolution-invariant axial range of 1.8\u2009mm, 33 times the depth of field of the conventional PAM counterpart. Our work opens new perspectives for PAM in biomedical sciences.",
"doi": "10.1038/s41467-017-00856-2",
"pmcid": "PMC5626698",
"issn": "2041-1723",
"publisher": "Nature Publishing Group",
"publication": "Nature Communications",
"publication_date": "2017-10-03",
"volume": "8",
"pages": "Art. No. 780"
},
{
"id": "authors:qe56w-5j307",
"collection": "authors",
"collection_id": "qe56w-5j307",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171020-152431819",
"type": "article",
"title": "Analysis of the potential for non-invasive imaging of oxygenation at heart depth, using ultrasound optical tomography (UOT) or photo-acoustic tomography (PAT)",
"author": [
{
"family_name": "Walther",
"given_name": "Andreas",
"clpid": "Walther-Andreas"
},
{
"family_name": "Rippe",
"given_name": "Lars",
"clpid": "Rippe-Lars"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Andersson-Engels",
"given_name": "Stefan",
"orcid": "0000-0001-5640-3122",
"clpid": "Andersson-Engels-Stefan"
},
{
"family_name": "Kr\u00f6ll",
"given_name": "Stefan",
"clpid": "Kr\u00f6ll-Stefan"
}
],
"abstract": "Despite the important medical implications, it is currently an open task to find optical non-invasive techniques that can image deep organs in humans. Addressing this, photo-acoustic tomography (PAT) has received a great deal of attention in the past decade, owing to favorable properties like high contrast and high spatial resolution. However, even with optimal components PAT cannot penetrate beyond a few centimeters, which still presents an important limitation of the technique. Here, we calculate the absorption contrast levels for PAT and for ultrasound optical tomography (UOT) and compare them to their relevant noise sources as a function of imaging depth. The results indicate that a new development in optical filters, based on rare-earth-ion crystals, can push the UOT technique significantly ahead of PAT. Such filters allow the contrast-to-noise ratio for UOT to be up to three orders of magnitude better than for PAT at depths of a few cm into the tissue. It also translates into a significant increase of the image depth of UOT compared to PAT, enabling deep organs to be imaged in humans in real time. Furthermore, such spectral holeburning filters are not sensitive to speckle decorrelation from the tissue and can operate at nearly any angle of incident light, allowing good light collection. We theoretically demonstrate the improved performance in the medically important case of non-invasive optical imaging of the oxygenation level of the frontal part of the human myocardial tissue. Our results indicate that further studies on UOT are of interest and that the technique may have large impact on future directions of biomedical optics.",
"doi": "10.1364/BOE.8.004523",
"pmcid": "PMC5654797",
"issn": "2156-7085",
"publisher": "Optical Society of America",
"publication": "Biomedical Optics Express",
"publication_date": "2017-10-01",
"series_number": "10",
"volume": "8",
"issue": "10",
"pages": "4523-4536"
},
{
"id": "authors:za4ds-knj03",
"collection": "authors",
"collection_id": "za4ds-knj03",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180905-105903271",
"type": "article",
"title": "Shining Future of Biomedical Optics",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Lihong V. Wang summarizes his tenure as Editor-in-Chief of the Journal of Biomedical Optics and introduces his successor, Brian Pogue, who will assume the role in January 2018.",
"doi": "10.1117/1.JBO.22.10.100101",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2017-10",
"series_number": "10",
"volume": "22",
"issue": "10",
"pages": "Art. No. 100101"
},
{
"id": "authors:10ftb-ery50",
"collection": "authors",
"collection_id": "10ftb-ery50",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170809-134617557",
"type": "article",
"title": "Homogenizing microwave illumination in thermoacoustic tomography by a linear-to-circular polarizer based on frequency selective surfaces",
"author": [
{
"family_name": "He",
"given_name": "Yu",
"clpid": "He-Yu"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Feng",
"given_name": "Xiaohua",
"clpid": "Feng-Xiaohua"
},
{
"family_name": "Liu",
"given_name": "Changjun",
"orcid": "0000-0003-0079-6793",
"clpid": "Liu-Changjun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A circularly polarized antenna, providing more homogeneous illumination compared to a linearly polarized antenna, is more suitable for microwave induced thermoacoustic tomography (TAT). The conventional realization of a circular polarization is by using a helical antenna, but it suffers from low efficiency, low power capacity, and limited aperture in TAT systems. Here, we report an implementation of a circularly polarized illumination method in TAT by inserting a single-layer linear-to-circular polarizer based on frequency selective surfaces between a pyramidal horn antenna and an imaging object. The performance of the proposed method was validated by both simulations and experimental imaging of a breast tumor phantom. The results showed that a circular polarization was achieved, and the resultant thermoacoustic signal-to-noise was twice greater than that in the helical antenna case. The proposed method is more desirable in a waveguide-based TAT system than the conventional method.",
"doi": "10.1063/1.4993942",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2017-08",
"series_number": "6",
"volume": "111",
"issue": "6",
"pages": "Art. No. 063703"
},
{
"id": "authors:mzjft-rgt25",
"collection": "authors",
"collection_id": "mzjft-rgt25",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170731-091004588",
"type": "article",
"title": "Multiview Hilbert transformation in full-ring transducer array-based photoacoustic computed tomography",
"author": [
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Based on the photoacoustic (PA) effect, PA tomography directly measures specific optical absorption, i.e., absorbed optical energy per unit volume. We recently developed a full-ring ultrasonic transducer array-based photoacoustic computed tomography (PACT) system for small-animal whole-body imaging. The system has a full-view detection angle and high in-plane resolution (\u223c100\u2009\u2009\u03bcm). However, due to the bandpass frequency response of the piezoelectric transducer elements and the limited elevational detection coverage of the full-ring transducer array, the reconstructed images present bipolar (i.e., both positive and negative) pixel values, which cause ambiguities in image interpretation for physicians and biologists. We propose a multiview Hilbert transformation method to recover the unipolar initial pressure for full-ring PACT. The effectiveness of the proposed algorithm was first validated by numerical simulations and then demonstrated with ex vivo mouse brain structural imaging and in vivo mouse whole-body imaging.",
"doi": "10.1117/1.JBO.22.7.076017",
"pmcid": "PMC5527266",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2017-07-26",
"series_number": "7",
"volume": "22",
"issue": "7",
"pages": "Art. No. 076017"
},
{
"id": "authors:nsfpv-qh706",
"collection": "authors",
"collection_id": "nsfpv-qh706",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180511-131505581",
"type": "article",
"title": "Noninvasive Determination of Melanoma Depth using a Handheld Photoacoustic Probe",
"author": [
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Tripathi",
"given_name": "Shivani V.",
"clpid": "Tripathi-S-V"
},
{
"family_name": "Rosman",
"given_name": "Ilana",
"clpid": "Rosman-I"
},
{
"family_name": "Ma",
"given_name": "Jun",
"clpid": "Ma-Jun"
},
{
"family_name": "Hai",
"given_name": "Pengfei",
"clpid": "Hai-Pengfei"
},
{
"family_name": "Linette",
"given_name": "Gerald P.",
"clpid": "Linette-G-P"
},
{
"family_name": "Council",
"given_name": "M. Laurin",
"clpid": "Council-M-L"
},
{
"family_name": "Fields",
"given_name": "Ryan C.",
"clpid": "Fields-R-C"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Cornelius",
"given_name": "Lynn A.",
"clpid": "Cornelius-L-A"
}
],
"abstract": "In this work, we propose applying photoacoustic tomography (PAT) to address this problem. Compared with traditional optical imaging methods, PAT uses ultrasonic waves, which give approximately 1,000 times less scattering than optical waves, breaking through the optical diffusion limit (\u223c1 mm in the skin) for penetration (Wang and Hu, 2012; Wang and Gao, 2014). In addition, by using optical excitation of acoustic waves due to light absorption, PAT provides improved contrast of melanin, which is deficient in ultrasonographic imaging. In previous mouse models, we measured a melanoma greater than 7 mm in depth (Zhou et al., 2015). Here we extend our work to patients with melanoma, with the aim of determining the accuracy of PAT-measured melanoma depth compared with the actual BD based on excisional biopsy results. In addition, we also compare our PAT measurement with the histologic measurement obtained from partial incisional biopsy to ultimately determine the predictability and application of PAT measurements in a clinical setting.",
"doi": "10.1016/j.jid.2017.01.016",
"pmcid": "PMC5963508",
"issn": "0022-202X",
"publisher": "Elsevier",
"publication": "Journal of Investigative Dermatology",
"publication_date": "2017-06",
"series_number": "6",
"volume": "137",
"issue": "6",
"pages": "1370-1372"
},
{
"id": "authors:v8sat-ysx44",
"collection": "authors",
"collection_id": "v8sat-ysx44",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190227-073226908",
"type": "article",
"title": "High-speed photoacoustic microscopy of mouse cortical microhemodynamics",
"author": [
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Chen",
"given_name": "Chun-Cheng",
"clpid": "Chen-Chun-Cheng"
},
{
"family_name": "Huang",
"given_name": "Chih-Hsien",
"clpid": "Huang-Chih-Hsien"
},
{
"family_name": "Li",
"given_name": "Yang",
"orcid": "0000-0002-4939-8174",
"clpid": "Li-Yang"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Chapman",
"given_name": "William",
"clpid": "Chapman-William"
},
{
"family_name": "Zou",
"given_name": "Jun",
"orcid": "0000-0002-9543-6135",
"clpid": "Zou-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We applied high\u2010speed photoacoustic microscopy (PAM) for both cortical microenvironment studies and dynamic brain studies, with micrometer\u2010level optical resolution and a millisecond\u2010level cross\u2010sectional imaging speed over a millimeter\u2010level field of view. We monitored blood flow redistribution in mini\u2010stroke mouse models and cerebral autoregulation induced by a vasoactive agent. Our results collectively suggest that high\u2010speed PAM is a promising tool for understanding dynamic neurophysiological phenomena, complementing conventional imaging modalities.",
"doi": "10.1002/jbio.201600236",
"pmcid": "PMC5576888",
"issn": "1864-063X",
"publisher": "Wiley",
"publication": "Journal of Biophotonics",
"publication_date": "2017-06",
"series_number": "6-7",
"volume": "10",
"issue": "6-7",
"pages": "792-798"
},
{
"id": "authors:v1p6v-7km33",
"collection": "authors",
"collection_id": "v1p6v-7km33",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170605-092443687",
"type": "article",
"title": "Photoacoustic imaging of voltage responses beyond the optical diffusion limit",
"author": [
{
"family_name": "Rao",
"given_name": "Bin",
"orcid": "0000-0001-6494-3110",
"clpid": "Rao-Bin"
},
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Shao",
"given_name": "Jin-Yu",
"clpid": "Shao-Jin-Yu"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Non-invasive optical imaging of neuronal voltage response signals in live brains is constrained in depth by the optical diffusion limit, which is due primarily to optical scattering by brain tissues. Although photoacoustic tomography breaks this limit by exciting the targets with diffused photons and detecting the resulting acoustic responses, it has not been demonstrated as a modality for imaging voltage responses. In this communication, we report the first demonstration of photoacoustic voltage response imaging in both in vitro HEK-293 cell cultures and in vivo mouse brain surfaces. Using spectroscopic photoacoustic tomography at isosbestic wavelengths, we can separate voltage response signals and hemodynamic signals on live brain surfaces. By imaging HEK-293 cell clusters through 4.5\u2009mm thick ex vivo rat brain tissue, we demonstrate photoacoustic tomography of cell membrane voltage responses beyond the optical diffusion limit. Although the current voltage dye does not immediately allow in vivo deep brain voltage response imaging, we believe our method opens up a feasible technical path for deep brain studies in the future.",
"doi": "10.1038/s41598-017-02458-w",
"pmcid": "PMC5451395",
"issn": "2045-2322",
"publisher": "Nature Publishing Group",
"publication": "Scientific Reports",
"publication_date": "2017-05-31",
"series_number": "1",
"volume": "7",
"issue": "1",
"pages": "Art. No. 2560"
},
{
"id": "authors:nqsd9-4mt53",
"collection": "authors",
"collection_id": "nqsd9-4mt53",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170516-164857493",
"type": "article",
"title": "Fast label-free multilayered histology-like imaging of human breast cancer by photoacoustic microscopy",
"author": [
{
"family_name": "Wong",
"given_name": "Terence T. W.",
"orcid": "0000-0001-6399-758X",
"clpid": "Wong-Terence-T-W"
},
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Hai",
"given_name": "Pengfei",
"clpid": "Hai-Pengfei"
},
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Pleitez",
"given_name": "Miguel A.",
"clpid": "Pleitez-M-A"
},
{
"family_name": "Aft",
"given_name": "Rebecca L.",
"clpid": "Aft-R-L"
},
{
"family_name": "Novack",
"given_name": "Deborah V.",
"clpid": "Novack-D-V"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The goal of breast-conserving surgery is to completely remove all of the cancer. Currently, no intraoperative tools can microscopically analyze the entire lumpectomy specimen, which results in 20 to 60% of patients undergoing second surgeries to achieve clear margins. To address this critical need, we have laid the foundation for the development of a device that could allow accurate intraoperative margin assessment. We demonstrate that by taking advantage of the intrinsic optical contrast of breast tissue, photoacoustic microscopy (PAM) can achieve multilayered histology-like imaging of the tissue surface. The high correlation of the PAM images to the conventional histologic images allows rapid computations of diagnostic features such as nuclear size and packing density, potentially identifying small clusters of cancer cells. Because PAM does not require tissue processing or staining, it can be performed promptly and intraoperatively, enabling immediate directed re-excision and reducing the number of second surgeries.",
"doi": "10.1126/sciadv.1602168",
"pmcid": "PMC5435415",
"issn": "2375-2548",
"publisher": "American Association for the Advancement of Science",
"publication": "Science Advances",
"publication_date": "2017-05-17",
"series_number": "5",
"volume": "3",
"issue": "5",
"pages": "Art. No. e1602168"
},
{
"id": "authors:8qdfs-x5n16",
"collection": "authors",
"collection_id": "8qdfs-x5n16",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170515-154135422",
"type": "article",
"title": "Single-impulse panoramic photoacoustic computed tomography of small-animal whole-body dynamics at high spatiotemporal resolution",
"author": [
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Ma",
"given_name": "Cheng",
"clpid": "Ma-Cheng"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-Konstantin-I"
},
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Chen",
"given_name": "Wanyi",
"clpid": "Chen-Wanyi"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Imaging of small animals has played an indispensable role in preclinical research by providing high-dimensional physiological, pathological and phenotypic insights with clinical relevance. Yet, pure optical imaging suffers from either shallow penetration (up to ~1\u20132\u2009mm) or a poor depth-to-resolution ratio (~3), and non-optical techniques for whole-body imaging of small animals lack either spatiotemporal resolution or functional contrast. Here, we demonstrate that stand-alone single-impulse panoramic photoacoustic computed tomography (SIP-PACT) mitigates these limitations by combining high spatiotemporal resolution (125 \u03bcm in-plane resolution, 50\u2009\u03bcs per frame data acquisition and 50 Hz frame rate), deep penetration (48 mm cross-sectional width in vivo), anatomical, dynamical and functional contrasts, and full-view fidelity. Using SIP-PACT, we imaged in vivo whole-body dynamics of small animals in real time and obtained clear sub-organ anatomical and functional details. We tracked unlabelled circulating melanoma cells and imaged the vasculature and functional connectivity of whole rat brains. SIP-PACT holds great potential for both preclinical imaging and clinical translation.",
"doi": "10.1038/s41551-017-0071",
"pmcid": "PMC5766044",
"issn": "2157-846X",
"publisher": "Nature Publishing Group",
"publication": "Nature Biomedical Engineering",
"publication_date": "2017-05",
"series_number": "5",
"volume": "1",
"issue": "5",
"pages": "Art. No. 0071"
},
{
"id": "authors:na7fb-mgs69",
"collection": "authors",
"collection_id": "na7fb-mgs69",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180911-164455137",
"type": "article",
"title": "Handheld optical-resolution photoacoustic microscopy",
"author": [
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Zhang",
"given_name": "Pengfei",
"orcid": "0000-0002-4226-1394",
"clpid": "Zhang-Pengfei"
},
{
"family_name": "Xu",
"given_name": "Song",
"clpid": "Xu-Song"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Zou",
"given_name": "Jun",
"orcid": "0000-0002-9543-6135",
"clpid": "Zou-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical-resolution photoacoustic microscopy (OR-PAM) offers label-free in vivo imaging with high spatial resolution by acoustically detecting optical absorption contrasts via the photoacoustic effect. We developed a compact handheld OR-PAM probe for fast photoacoustic imaging. Different from benchtop microscopes, the handheld probe provides flexibility in imaging various anatomical sites. Resembling a cup in size, the probe uses a two-axis water-immersible microelectromechanical system mirror to scan both the illuminating optical beam and resultant acoustic beam. The system performance was tested in vivo by imaging the capillary bed in a mouse ear and both the capillary bed and a mole on a human volunteer.",
"doi": "10.1117/1.jbo.22.4.041002",
"pmcid": "PMC5075719",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2017-04",
"series_number": "4",
"volume": "22",
"issue": "4",
"pages": "Art. No. 041002"
},
{
"id": "authors:nmhv0-98469",
"collection": "authors",
"collection_id": "nmhv0-98469",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180911-144144268",
"type": "article",
"title": "Mitigation of artifacts due to isolated acoustic heterogeneities in photoacoustic computed tomography using a variable data truncation-based reconstruction method",
"author": [
{
"family_name": "Poudel",
"given_name": "Joemini",
"clpid": "Poudel-J"
},
{
"family_name": "Matthews",
"given_name": "Thomas P.",
"clpid": "Matthews-T-P"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic computed tomography (PACT) is an emerging computed imaging modality that exploits optical contrast and ultrasonic detection principles to form images of the absorbed optical energy density within tissue. If the object possesses spatially variant acoustic properties that are unaccounted for by the reconstruction method, the estimated image can contain distortions. While reconstruction methods have recently been developed to compensate for this effect, they generally require the object's acoustic properties to be known a priori. To circumvent the need for detailed information regarding an object's acoustic properties, we previously proposed a half-time reconstruction method for PACT. A half-time reconstruction method estimates the PACT image from a data set that has been temporally truncated to exclude the data components that have been strongly aberrated. However, this method can be improved upon when the approximate sizes and locations of isolated heterogeneous structures, such as bones or gas pockets, are known. To address this, we investigate PACT reconstruction methods that are based on a variable data truncation (VDT) approach. The VDT approach represents a generalization of the half-time approach, in which the degree of temporal truncation for each measurement is determined by the distance between the corresponding ultrasonic transducer location and the nearest known bone or gas void location. Computer-simulated and experimental data are employed to demonstrate the effectiveness of the approach in mitigating artifacts due to acoustic heterogeneities.",
"doi": "10.1117/1.JBO.22.4.041018",
"pmcid": "PMC5340213",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2017-04",
"series_number": "4",
"volume": "22",
"issue": "4",
"pages": "Art. No. 041018"
},
{
"id": "authors:tepa7-5yq21",
"collection": "authors",
"collection_id": "tepa7-5yq21",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180911-145451669",
"type": "article",
"title": "Label-free high-throughput detection and quantification of circulating melanoma tumor cell clusters by linear-array-based photoacoustic tomography",
"author": [
{
"family_name": "Hai",
"given_name": "Pengfei",
"clpid": "Hai-Pengfei"
},
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Ma",
"given_name": "Jun",
"clpid": "Ma-Jun"
},
{
"family_name": "Li",
"given_name": "Yang",
"orcid": "0000-0002-4939-8174",
"clpid": "Li-Yang"
},
{
"family_name": "Shao",
"given_name": "Jin-Yu",
"clpid": "Shao-Jin-Yu"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Circulating tumor cell (CTC) clusters, arising from multicellular groupings in a primary tumor, greatly elevate the metastatic potential of cancer compared with single CTCs. High-throughput detection and quantification of CTC clusters are important for understanding the tumor metastatic process and improving cancer therapy. Here, we applied a linear-array-based photoacoustic tomography (LA-PAT) system and improved the image reconstruction for label-free high-throughput CTC cluster detection and quantification.",
"doi": "10.1117/1.JBO.22.4.041004",
"pmcid": "PMC5995136",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2017-04",
"series_number": "4",
"volume": "22",
"issue": "4",
"pages": "Art. No. 041004"
},
{
"id": "authors:pzwt5-krs28",
"collection": "authors",
"collection_id": "pzwt5-krs28",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170602-071608181",
"type": "article",
"title": "Dry coupling for whole-body small-animal photoacoustic computed tomography",
"author": [
{
"family_name": "Yeh",
"given_name": "Chenghung",
"clpid": "Yeh-Chenghung"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Chen",
"given_name": "Wanyi",
"clpid": "Chen-Wanyi"
},
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have enhanced photoacoustic computed tomography with dry acoustic coupling that eliminates water immersion anxiety and wrinkling of the animal and facilitates incorporating complementary modalities and procedures. The dry acoustic coupler is made of a tubular elastic membrane enclosed by a closed transparent water tank. The tubular membrane ensures water-free contact with the animal, and the closed water tank allows pressurization for animal stabilization. The dry coupler was tested using a whole-body small-animal ring-shaped photoacoustic computed tomography system. Dry coupling was found to provide image quality comparable to that of conventional water coupling.",
"doi": "10.1117/1.JBO.22.4.041017",
"pmcid": "PMC5995148",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2017-04",
"series_number": "4",
"volume": "22",
"issue": "4",
"pages": "Art. No. 041017"
},
{
"id": "authors:7xtkb-pzm93",
"collection": "authors",
"collection_id": "7xtkb-pzm93",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180911-150529367",
"type": "article",
"title": "Use of a single xenon flash lamp for photoacoustic computed tomography of multiple-centimeter-thick biological tissue ex vivo and a whole mouse body in vivo",
"author": [
{
"family_name": "Wong",
"given_name": "Terence T. W.",
"orcid": "0000-0001-6399-758X",
"clpid": "Wong-Terence-T-W"
},
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "While lasers have been commonly used as illumination sources in photoacoustic (PA) imaging, their high purchase and maintenance costs, as well as their bulkiness, have hindered the rapid clinical dissemination of PA imaging. With this in mind, we explore an alternative illumination source for PA tomography\u2014a xenon flash lamp with high pulse energy and a microsecond pulse width. We demonstrate that, by using a single xenon flash lamp, we can image both a black latex cord placed in chicken breast tissue at a depth of up to 3.5 cm ex vivo and an entire mouse body in vivo. Our findings indicate that the xenon flash lamp, producing optical illumination that is safe for humans, can be potentially applied to human tissue imaging.",
"doi": "10.1117/1.JBO.22.4.041003",
"pmcid": "PMC5075722",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2017-04",
"series_number": "4",
"volume": "22",
"issue": "4",
"pages": "Art. No. 041003"
},
{
"id": "authors:vjg3a-9ht16",
"collection": "authors",
"collection_id": "vjg3a-9ht16",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190227-083443703",
"type": "article",
"title": "Focusing light inside dynamic scattering media with millisecond digital optical phase conjugation",
"author": [
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Ma",
"given_name": "Cheng",
"clpid": "Ma-Cheng"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Wavefront shaping based on digital optical phase conjugation (DOPC) focuses light through or inside scattering media, but the low speed of DOPC prevents it from being applied to thick, living biological tissue. Although a fast DOPC approach was recently developed, the reported single-shot wavefront measurement method does not work when the goal is to focus light inside, instead of through, highly scattering media. Here, using a ferroelectric liquid crystal based spatial light modulator, we develop a simpler but faster DOPC system that focuses light not only through, but also inside scattering media. By controlling 2.6\u00d710^5 optical degrees of freedom, our system focused light through 3 mm thick moving chicken tissue, with a system latency of 3.0 ms. Using ultrasound-guided DOPC, along with a binary wavefront measurement method, our system focused light inside a scattering medium comprising moving tissue with a latency of 6.0 ms, which is one to two orders of magnitude shorter than those of previous digital wavefront shaping systems. Since the demonstrated speed approaches tissue decorrelation rates, this work is an important step toward in vivo deep-tissue non-invasive optical imaging, manipulation, and therapy.",
"doi": "10.1364/optica.4.000280",
"pmcid": "PMC5555171",
"issn": "2334-2536",
"publisher": "Optical Society of America",
"publication": "Optica",
"publication_date": "2017-02-20",
"series_number": "2",
"volume": "4",
"issue": "2",
"pages": "280-288"
},
{
"id": "authors:3sf2r-f1r63",
"collection": "authors",
"collection_id": "3sf2r-f1r63",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190226-135644616",
"type": "article",
"title": "Suppressing excitation effects in microwave induced thermoacoustic tomography by multi-view Hilbert transformation",
"author": [
{
"family_name": "He",
"given_name": "Yu",
"clpid": "He-Yu"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Liu",
"given_name": "Changjun",
"orcid": "0000-0003-0079-6793",
"clpid": "Liu-Changjun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Microwave induced thermoacoustic tomography (TAT) images usually suffer from distortions arising from the microwave polarization effect and standing wave effect. The microwave polarization effect, resulting from linearly polarized microwave illumination, splits the image of the object along the polarization direction, while the standing wave effect, when the object size is larger than the microwave wavelength within the object, modulates the image of the object. Both effects cause non-uniform energy distribution in a uniformly absorbing object and create artifacts in the reconstructed images. To address these problems in TAT, we propose an image reconstruction method that combines multi-view Hilbert transformation with the back-projection algorithm. We experimentally validate this method by imaging breast and brain tumor phantoms, showing that the aforementioned distortions are significantly suppressed. We anticipate that this method will contribute to clinical tumor diagnosis.",
"doi": "10.1063/1.4975204",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2017-01-30",
"series_number": "5",
"volume": "110",
"issue": "5",
"pages": "Art. No. 053701"
},
{
"id": "authors:dbx0m-sdw63",
"collection": "authors",
"collection_id": "dbx0m-sdw63",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190226-141747713",
"type": "article",
"title": "Direct measurement of hypoxia in a xenograft multiple myeloma model by optical-resolution photoacoustic microscopy",
"author": [
{
"family_name": "Imai",
"given_name": "Toru",
"orcid": "0000-0002-9497-8549",
"clpid": "Imai-Toru"
},
{
"family_name": "Muz",
"given_name": "Barbara",
"orcid": "0000-0003-4125-4624",
"clpid": "Muz-B"
},
{
"family_name": "Yeh",
"given_name": "Cheng-Hung",
"clpid": "Yeh-Cheng-Hung"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Azab",
"given_name": "Abdel Kareem",
"orcid": "0000-0002-6371-2780",
"clpid": "Azab-A-K"
},
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Using photoacoustic microscopy (PAM), we evaluated non-invasively oxygenation and vascularization in vivodue to multiple myeloma (MM) progression. Mice injected with MM.1S-GFP were monitored with a fluorescence microscope for tumor progression. In vivo PAM of the cerebral bone marrow quantified the total oxygen saturation (sO_2). At 28 days after the MM cell injection, the total sO_2 had decreased by half in the developing tumor regions, while in the non-tumor regions it had decreased by 20% compared with the value at one day post MM injection. The blood vessel density was reduced by 35% in the developing tumor regions, while in the non-tumor regions it was reduced by 8% compared with the value at one day post MM injection. Hence, PAM corroborated the development of hypoxia due to MM progression and demonstrated decreased vascularization surrounding the tumor areas.",
"doi": "10.1080/15384047.2016.1276137",
"pmcid": "PMC5362988",
"issn": "1538-4047",
"publisher": "Taylor & Francis",
"publication": "Cancer Biology and Therapy",
"publication_date": "2017-01-26",
"series_number": "2",
"volume": "18",
"issue": "2",
"pages": "101-105"
},
{
"id": "authors:qnk8q-wqz40",
"collection": "authors",
"collection_id": "qnk8q-wqz40",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190226-141116141",
"type": "article",
"title": "Sub-Nyquist sampling boosts targeted light transport through opaque scattering media",
"author": [
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Ma",
"given_name": "Cheng",
"clpid": "Ma-Cheng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical time-reversal techniques are being actively developed to focus light through or inside opaque scattering media. When applied to biological tissue, these techniques promise to revolutionize biophotonics by enabling deep-tissue non-invasive optical imaging, optogenetics, optical tweezing, and phototherapy. In all previous optical time-reversal experiments, the scattered light field was well-sampled during wavefront measurement and wavefront reconstruction, following the Nyquist sampling criterion. Here, we overturn this conventional practice by demonstrating that even when the scattered field is under-sampled, light can still be focused through or inside scattering media. Even more surprisingly, we show both theoretically and experimentally that the focus achieved by under-sampling can be one order of magnitude brighter than that achieved under the well-sampling conditions used in previous works, where 3\u00d73 to 5\u00d75 pixels were used to sample one speckle grain on average. Moreover, sub-Nyquist sampling improves the signal-to-noise ratio and the collection efficiency of the scattered light. We anticipate that this newly explored under-sampling scheme will transform the understanding of optical time reversal and boost the performance of optical imaging, manipulation, and communication through opaque scattering media.",
"doi": "10.1364/OPTICA.4.000097",
"pmcid": "PMC5493046",
"issn": "2334-2536",
"publisher": "Optical Society of America",
"publication": "Optica",
"publication_date": "2017-01-20",
"series_number": "1",
"volume": "4",
"issue": "1",
"pages": "97-102"
},
{
"id": "authors:yq0rj-p2057",
"collection": "authors",
"collection_id": "yq0rj-p2057",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190226-140244418",
"type": "article",
"title": "Single-shot real-time video recording of a photonic Mach cone induced by a scattered light pulse",
"author": [
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Ma",
"given_name": "Cheng",
"clpid": "Ma-Cheng"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Chen",
"given_name": "Yujia",
"clpid": "Chen-Yujia"
},
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Ultrafast video recording of spatiotemporal light distribution in a scattering medium has a significant impact in biomedicine. Although many simulation tools have been implemented to model light propagation in scattering media, existing experimental instruments still lack sufficient imaging speed to record transient light-scattering events in real time. We report single-shot ultrafast video recording of a light-induced photonic Mach cone propagating in an engineered scattering plate assembly. This dynamic light-scattering event was captured in a single camera exposure by lossless-encoding compressed ultrafast photography at 100 billion frames per second. Our experimental results are in excellent agreement with theoretical predictions by time-resolved Monte Carlo simulation. This technology holds great promise for next-generation biomedical imaging instrumentation.",
"doi": "10.1126/sciadv.1601814",
"pmcid": "PMC5249257",
"issn": "2375-2548",
"publisher": "American Association for the Advancement of Science",
"publication": "Science Advances",
"publication_date": "2017-01-20",
"volume": "3",
"pages": "Art. No. e1601814"
},
{
"id": "authors:059h2-bcq45",
"collection": "authors",
"collection_id": "059h2-bcq45",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190226-135243415",
"type": "article",
"title": "Comparative Effects of Linearly and Circularly Polarized Illumination on Microwave-Induced Thermoacoustic Tomography",
"author": [
{
"family_name": "He",
"given_name": "Yu",
"clpid": "He-Yu"
},
{
"family_name": "Liu",
"given_name": "Changjun",
"orcid": "0000-0003-0079-6793",
"clpid": "Liu-Changjun"
},
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Homogeneous illumination is important in microwave-induced thermoacoustic tomography (TAT) because it directly determines the quantification of the reconstructed images of objects. In this work, we studied the effects of both linearly and circularly polarized microwave illuminations on TAT images. A customized horn antenna and a helical antenna working at 3 GHz were used to provide linearly polarized and circularly polarized illuminations, respectively. Based on our simulated and experimental results from tumor phantoms, the imaged patterns of the targets showed dependence on their permittivity. The target size and microwave wavelength within the target affected the microwave power distribution, which resulted in different reconstructed images. We analyzed the effect of the microwave penetration depth on TAT images as well. The images under circularly polarized illumination presented better quality than those under linearly polarized illumination. Hence, circularly polarized illumination can potentially better detect breast tumors in clinical applications.",
"doi": "10.1109/lawp.2017.2652853",
"issn": "1536-1225",
"publisher": "IEEE",
"publication": "IEEE Antennas and Wireless Propagation Letters",
"publication_date": "2017-01-16",
"volume": "16",
"pages": "1593-1596"
},
{
"id": "authors:b348c-yb111",
"collection": "authors",
"collection_id": "b348c-yb111",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190227-081659351",
"type": "article",
"title": "In vivo label-free photoacoustic flow cytography and on-the-spot laser killing of single circulating melanoma cells",
"author": [
{
"family_name": "He",
"given_name": "Yun",
"clpid": "He-Yun"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Huang",
"given_name": "Chih-Hsien",
"clpid": "Huang-Chih-Hsien"
},
{
"family_name": "Zou",
"given_name": "Jun",
"orcid": "0000-0002-9543-6135",
"clpid": "Zou-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Metastasis causes as many as 90% of cancer-related deaths, especially for the deadliest skin cancer, melanoma. Since hematogenous dissemination of circulating tumor cells is the major route of metastasis, detection and destruction of circulating tumor cells are vital for impeding metastasis and improving patient prognosis. Exploiting the exquisite intrinsic optical absorption contrast of circulating melanoma cells, we developed dual-wavelength photoacoustic flow cytography coupled with a nanosecond-pulsed melanoma-specific laser therapy mechanism. We have successfully achieved in vivo label-free imaging of rare single circulating melanoma cells in both arteries and veins of mice. Further, the photoacoustic signal from a circulating melanoma cell immediately hardware-triggers a lethal pinpoint laser irradiation to kill it on the spot in a thermally confined manner without causing collateral damage. A pseudo-therapy study including both in vivo and in vitro experiments demonstrated the performance and the potential clinical value of our method, which can facilitate early treatment of metastasis by clearing circulating tumor cells from vasculature.",
"doi": "10.1038/srep39616",
"pmcid": "PMC5175175",
"issn": "2045-2322",
"publisher": "Nature Publishing Group",
"publication": "Scientific Reports",
"publication_date": "2016-12-21",
"volume": "6",
"pages": "Art. No. 39616"
},
{
"id": "authors:qhqq9-z0f40",
"collection": "authors",
"collection_id": "qhqq9-z0f40",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180905-104549630",
"type": "article",
"title": "Hybridized wavefront shaping for high-speed, high-efficiency focusing through dynamic diffusive media",
"author": [
{
"family_name": "Hemphill",
"given_name": "Ashton S.",
"clpid": "Hemphill-A-S"
},
{
"family_name": "Tay",
"given_name": "Jian Wei",
"clpid": "Tay-Jian-Wei"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "One of the prime limiting factors of optical imaging in biological applications is the diffusion of light by tissue, which prevents focusing at depths greater than the optical diffusion limit (typically \u223c1\u2009\u2009mm). To overcome this challenge, wavefront shaping techniques that use a spatial light modulator (SLM) to correct the phase of the incident wavefront have recently been developed. These techniques are able to focus light through scattering media beyond the optical diffusion limit. However, the low speeds of typically used liquid crystal SLMs limit the focusing speed. Here, we present a method using a digital micromirror device (DMD) and an electro-optic modulator (EOM) to measure the scattering-induced aberrations, and using a liquid crystal SLM to apply the correction to the illuminating wavefront. By combining phase modulation from an EOM with the DMD's ability to provide selective illumination, we exploit the DMD's higher refresh rate for phase measurement. We achieved focusing through scattering media in less than 8 ms, which is sufficiently short for certain in vivo applications, as it is comparable to the speckle correlation time of living tissue.",
"doi": "10.1117/1.JBO.21.12.121502",
"pmcid": "PMC5019185",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2016-12",
"series_number": "12",
"volume": "21",
"issue": "12",
"pages": "Art. No. 121502"
},
{
"id": "authors:5v388-qjk48",
"collection": "authors",
"collection_id": "5v388-qjk48",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180905-143750704",
"type": "article",
"title": "Focusing light through biological tissue and tissue-mimicking phantoms up to 9.6 cm in thickness with digital optical phase conjugation",
"author": [
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Ma",
"given_name": "Cheng",
"clpid": "Ma-Cheng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical phase conjugation (OPC)-based wavefront shaping techniques focus light through or within scattering media, which is critically important for deep-tissue optical imaging, manipulation, and therapy. However, to date, the sample thickness in OPC experiments has been limited to only a few millimeters. Here, by using a laser with a long coherence length and an optimized digital OPC system that can safely deliver more light power, we focused 532-nm light through tissue-mimicking phantoms up to 9.6 cm thick, as well as through ex vivo chicken breast tissue up to 2.5 cm thick. Our results demonstrate that OPC can be achieved even when photons have experienced on average 1000 scattering events. The demonstrated penetration of nearly 10 cm (\u223c100 transport mean free paths) has never been achieved before by any optical focusing technique, and it shows the promise of OPC for deep-tissue noninvasive optical imaging, manipulation, and therapy.",
"doi": "10.1117/1.JBO.21.8.085001",
"pmcid": "PMC4982119",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2016-08",
"series_number": "8",
"volume": "21",
"issue": "8",
"pages": "Art. No. 085001"
},
{
"id": "authors:97kqm-ecb36",
"collection": "authors",
"collection_id": "97kqm-ecb36",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170517-113034626",
"type": "article",
"title": "A practical guide to photoacoustic tomography in the life sciences",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
}
],
"abstract": "The life sciences can benefit greatly from imaging technologies that connect microscopic discoveries with macroscopic observations. One technology uniquely positioned to provide such benefits is photoacoustic tomography (PAT), a sensitive modality for imaging optical absorption contrast over a range of spatial scales at high speed. In PAT, endogenous contrast reveals a tissue's anatomical, functional, metabolic, and histologic properties, and exogenous contrast provides molecular and cellular specificity. The spatial scale of PAT covers organelles, cells, tissues, organs, and small animals. Consequently, PAT is complementary to other imaging modalities in contrast mechanism, penetration, spatial resolution, and temporal resolution. We review the fundamentals of PAT and provide practical guidelines for matching PAT systems with research needs. We also summarize the most promising biomedical applications of PAT, discuss related challenges, and envision PAT's potential to lead to further breakthroughs.",
"doi": "10.1038/nmeth.3925",
"pmcid": "PMC4980387",
"issn": "1548-7091",
"publisher": "Nature Publishing Group",
"publication": "Nature Methods",
"publication_date": "2016-08",
"series_number": "8",
"volume": "13",
"issue": "8",
"pages": "627-638"
},
{
"id": "authors:hv3a1-ch316",
"collection": "authors",
"collection_id": "hv3a1-ch316",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160721-095752274",
"type": "article",
"title": "Reversibly switchable fluorescence microscopy with enhanced resolution and image contrast",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Shcherbakova",
"given_name": "Daria M.",
"clpid": "Shcherbakova-D-M"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Krumholz",
"given_name": "Arie",
"clpid": "Krumholz-A"
},
{
"family_name": "Lorca",
"given_name": "Ramon A.",
"clpid": "Lorca-R-A"
},
{
"family_name": "Reinl",
"given_name": "Erin",
"clpid": "Reinl-E"
},
{
"family_name": "England",
"given_name": "Sarah K.",
"clpid": "England-S-K"
},
{
"family_name": "Verkhusha",
"given_name": "Vladislav V.",
"orcid": "0000-0002-2083-8121",
"clpid": "Verkhusha-V-V"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Confocal microscopy with optical sectioning has revolutionized biological studies by providing sharper images than conventional optical microscopy. Here, we introduce a fluorescence imaging method with enhanced resolution and imaging contrast, which can be implemented using a commercial confocal microscope setup. This approach, called the reversibly switchable photo-imprint microscopy (rsPIM), is based on the switching dynamics of reversibly switchable fluorophores. When the fluorophores are switched from the bright (ON) state to the dark (OFF) state, their switching rate carries the information about the local excitation light intensity. In rsPIM, a polynomial function is used to fit the fluorescence signal decay during the transition. The extracted high-order coefficient highlights the signal contribution from the center of the excitation volume, and thus sharpens the resolution in all dimensions. In particular, out-of-focus signals are greatly blocked for large targets, and thus the image contrast is considerably enhanced. Notably, since the fluorophores can be cycled between the ON and OFF states, the whole imaging process can be repeated. RsPIM imaging with enhanced image contrast was demonstrated in both fixed and live cells using a reversibly switchable synthetic dye and a genetically encoded red fluorescent protein. Since rsPIM does not require the modification of commercial microscope systems, it may provide a simple and cost-effective solution for subdiffraction imaging of live cells.",
"doi": "10.1117/1.JBO.19.8.086018",
"pmcid": "PMC4140226",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2016-07-25",
"series_number": "8",
"volume": "19",
"issue": "8",
"pages": "Art. No. 086018"
},
{
"id": "authors:7ztec-mn219",
"collection": "authors",
"collection_id": "7ztec-mn219",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190227-095416432",
"type": "article",
"title": "Space- and intensity-constrained reconstruction for compressed ultrafast photography",
"author": [
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Chen",
"given_name": "Yujia",
"clpid": "Chen-Yujia"
},
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Xu",
"given_name": "Qiaofeng",
"clpid": "Xu-Qiaofeng"
},
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Ma",
"given_name": "Cheng",
"clpid": "Ma-Cheng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The single-shot compressed ultrafast photography (CUP) camera is the fastest receive-only camera in the world. In this Letter, we introduce an external CCD camera and a space- and intensity-constrained (SIC) reconstruction algorithm to improve the image quality of CUP. The external CCD camera takes a time-unsheared image of the dynamic scene. Unlike the previously used unconstrained algorithm, the proposed algorithm incorporates both spatial and intensity constraints based on the additional prior information provided by the external CCD camera. First, a spatial mask is extracted from the time-unsheared image to define the zone of action. Next, an intensity threshold is determined based on the similarity between the temporally projected image of the reconstructed datacube and the time-unsheared image. Both simulation and experimental studies show that the SIC reconstruction improves the spatial resolution, contrast, and general quality of the reconstructed image.",
"doi": "10.1364/optica.3.000694",
"pmcid": "PMC5538792",
"issn": "2334-2536",
"publisher": "Optical Society of America",
"publication": "Optica",
"publication_date": "2016-07-20",
"series_number": "7",
"volume": "3",
"issue": "7",
"pages": "694-697"
},
{
"id": "authors:g9fte-va502",
"collection": "authors",
"collection_id": "g9fte-va502",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180905-161844995",
"type": "article",
"title": "High-speed, sparse-sampling three-dimensional photoacoustic computed tomography in vivo based on principal component analysis",
"author": [
{
"family_name": "Meng",
"given_name": "Jing",
"orcid": "0000-0002-9069-8988",
"clpid": "Meng-Jing"
},
{
"family_name": "Jiang",
"given_name": "Zibo",
"clpid": "Jiang-Zibo"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Park",
"given_name": "Jongin",
"clpid": "Park-Jongin"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Sun",
"given_name": "Mingjian",
"clpid": "Sun-Mingjian"
},
{
"family_name": "Zhang",
"given_name": "Yuanke",
"clpid": "Zhang-Yuanke"
},
{
"family_name": "Song",
"given_name": "Liang",
"clpid": "Song-Liang"
}
],
"abstract": "Photoacoustic computed tomography (PACT) has emerged as a unique and promising technology for multiscale biomedical imaging. To fully realize its potential for various preclinical and clinical applications, development of systems with high imaging speed, reasonable cost, and manageable data flow are needed. Sparse-sampling PACT with advanced reconstruction algorithms, such as compressed-sensing reconstruction, has shown potential as a solution to this challenge. However, most such algorithms require iterative reconstruction and thus intense computation, which may lead to excessively long image reconstruction times. Here, we developed a principal component analysis (PCA)-based PACT (PCA-PACT) that can rapidly reconstruct high-quality, three-dimensional (3-D) PACT images with sparsely sampled data without requiring an iterative process. In vivo images of the vasculature of a human hand were obtained, thus validating the PCA-PACT method. The results showed that, compared with the back-projection (BP) method, PCA-PACT required \u223c50% fewer measurements and \u223c40% less time for image reconstruction, and the imaging quality was almost the same as that for BP with full sampling. In addition, compared with compressed sensing-based PACT, PCA-PACT had approximately sevenfold faster imaging speed with higher imaging accuracy. This work suggests a promising approach for low-cost, 3-D, rapid PACT for various biomedical applications.",
"doi": "10.1117/1.JBO.21.7.076007",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2016-07",
"series_number": "7",
"volume": "21",
"issue": "7",
"pages": "Art. No. 076007"
},
{
"id": "authors:wpn6q-p7815",
"collection": "authors",
"collection_id": "wpn6q-p7815",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180911-164455001",
"type": "article",
"title": "Label-free photoacoustic tomography of whole mouse brain structures ex vivo",
"author": [
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Li",
"given_name": "Guo",
"clpid": "Li-Guo"
},
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Sheng",
"given_name": "Qiwei",
"clpid": "Sheng-Qiwei"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Capitalizing on endogenous hemoglobin contrast, photoacoustic-computed tomography (PACT), a deep-tissue high-resolution imaging modality, has drawn increasing interest in neuroimaging. However, most existing studies are limited to functional imaging on the cortical surface and the deep brain structural imaging capability of PACT has never been demonstrated. Here, we explicitly studied the limiting factors of deep brain PACT imaging. We found that the skull distorted the acoustic signal and blood suppressed the structural contrast from other chromophores. When the two effects are mitigated, PACT can potentially provide high-resolution label-free imaging of structures in the entire mouse brain. With 100-\u03bcm in-plane resolution, we can clearly identify major structures of the brain, which complements magnetic resonance microscopy for imaging small-animal brain structures. Spectral PACT studies indicate that structural contrasts mainly originate from cytochrome distribution and that the presence of lipid sharpens the image contrast; brain histology results provide further validation. The feasibility of imaging the structure of the brain in vivo is also discussed. Our results demonstrate that PACT is a promising modality for both structural and functional brain imaging.",
"doi": "10.1117/1.nph.3.3.035001",
"pmcid": "PMC5696384",
"issn": "2329-423X",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Neurophotonics",
"publication_date": "2016-07",
"series_number": "3",
"volume": "3",
"issue": "3",
"pages": "Art. No. 035001"
},
{
"id": "authors:2hwhk-ng639",
"collection": "authors",
"collection_id": "2hwhk-ng639",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190227-094048458",
"type": "article",
"title": "Lock-in camera based heterodyne holography for ultrasound-modulated optical tomography inside dynamic scattering media",
"author": [
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Ma",
"given_name": "Cheng",
"clpid": "Ma-Cheng"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Ultrasound-modulated optical tomography (UOT) images optical contrast deep inside scattering media. Heterodyne holography based UOT is a promising technique that uses a camera for parallel speckle detection. In previous works, the speed of data acquisition was limited by the low frame rates of conventional cameras. In addition, when the signal-to-background ratio was low, these cameras wasted most of their bits representing an informationless background, resulting in extremely low efficiencies in the use of bits. Here, using a lock-in camera, we increase the bit efficiency and reduce the data transfer load by digitizing only the signal after rejecting the background. Moreover, compared with the conventional four-frame based amplitude measurement method, our single-frame method is more immune to speckle decorrelation. Using lock-in camera based UOT with an integration time of 286\u2009\u03bcs, we imaged an absorptive object buried inside a dynamic scattering medium exhibiting a speckle correlation time (\u03c4_c) as short as 26\u2009\u03bcs. Since our method can tolerate speckle decorrelation faster than that found in living biological tissue (\u03c4_c \u223c 100\u20131000\u2009\u03bcs), it is promising for in vivo deep tissue non-invasive imaging.",
"doi": "10.1063/1.4953630",
"pmcid": "PMC4957977",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2016-06-06",
"series_number": "23",
"volume": "108",
"issue": "23",
"pages": "Art. No. 231106"
},
{
"id": "authors:mz831-1rb88",
"collection": "authors",
"collection_id": "mz831-1rb88",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180906-160753296",
"type": "article",
"title": "Grueneisen relaxation photoacoustic microscopy in vivo",
"author": [
{
"family_name": "Ma",
"given_name": "Jun",
"clpid": "Ma-Jun"
},
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Hai",
"given_name": "Pengfei",
"clpid": "Hai-Pengfei"
},
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Grueneisen relaxation photoacoustic microscopy (GR-PAM) can achieve optically defined axial resolution, but it has been limited to ex vivo demonstrations so far. Here, we present the first in vivo image of a mouse brain acquired with GR-PAM. To induce the GR effect, an intensity-modulated continuous-wave laser was employed to heat absorbing objects. In phantom experiments, an axial resolution of 12.5\u2009\u2009\u03bcm was achieved, which is sixfold better than the value achieved by conventional optical-resolution PAM. This axial-resolution improvement was further demonstrated by imaging a mouse brain in vivo, where significantly narrower axial profiles of blood vessels were observed. The in vivo demonstration of GR-PAM shows the potential of this modality for label-free and high-resolution anatomical and functional imaging of biological tissues.",
"doi": "10.1117/1.JBO.21.6.066005",
"pmcid": "PMC4897030",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2016-06",
"series_number": "6",
"volume": "21",
"issue": "6",
"pages": "Art. No. 066005"
},
{
"id": "authors:t9wnz-j9n14",
"collection": "authors",
"collection_id": "t9wnz-j9n14",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190227-103531175",
"type": "article",
"title": "Joint Reconstruction of Absorbed Optical Energy Density and Sound Speed Distributions in Photoacoustic Computed Tomography: A Numerical Investigation",
"author": [
{
"family_name": "Huang",
"given_name": "Chao",
"clpid": "Huang-Chao"
},
{
"family_name": "Wang",
"given_name": "Kun",
"clpid": "Wang-Kun"
},
{
"family_name": "Schoonover",
"given_name": "Robert W.",
"clpid": "Schoonover-R-W"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
}
],
"abstract": "Photoacoustic computed tomography (PACT) is a rapidly emerging bioimaging modality that seeks to reconstruct an estimate of the absorbed optical energy density within an object. Conventional PACT image reconstruction methods assume a constant speed-of-sound (SOS), which can result in image artifacts when acoustic aberrations are significant. It has been demonstrated that incorporating knowledge of an object's SOS distribution into a PACT image reconstruction method can improve image quality. However, in many cases, the SOS distribution cannot be accurately and/or conveniently estimated prior to the PACT experiment. Because variations in the SOS distribution induce aberrations in the measured photoacoustic wavefields, certain information regarding an object's SOS distribution is encoded in the PACT measurement data. Based on this observation, a joint reconstruction (JR) problem has been proposed in which the SOS distribution is concurrently estimated along with the sought-after absorbed optical energy density from the photoacoustic measurement data. A broad understanding of the extent to which the JR problem can be accurately and reliably solved has not been reported. In this work, a series of numerical experiments is described that elucidate some important properties of the JR problem that pertain to its practical feasibility. To accomplish this, an optimization-based formulation of the JR problem is developed that yields a nonlinear iterative algorithm that alternatively updates the two image estimates. Heuristic analytic insights into the reconstruction problem are also provided. These results confirm the ill-conditioned nature of the joint reconstruction problem that will present significant challenges for practical applications.",
"doi": "10.1109/tci.2016.2523427",
"pmcid": "PMC5693255",
"issn": "2333-9403",
"publisher": "IEEE",
"publication": "IEEE Transactions on Computational Imaging",
"publication_date": "2016-06",
"series_number": "2",
"volume": "2",
"issue": "2",
"pages": "136-149"
},
{
"id": "authors:rrmmz-r9q74",
"collection": "authors",
"collection_id": "rrmmz-r9q74",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180906-161627909",
"type": "article",
"title": "Tutorial on photoacoustic tomography",
"author": [
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) has become one of the fastest growing fields in biomedical optics. Unlike pure optical imaging, such as confocal microscopy and two-photon microscopy, PAT employs acoustic detection to image optical absorption contrast with high-resolution deep into scattering tissue. So far, PAT has been widely used for multiscale anatomical, functional, and molecular imaging of biological tissues. We focus on PAT's basic principles, major implementations, imaging contrasts, and recent applications.",
"doi": "10.1117/1.JBO.21.6.061007",
"pmcid": "PMC4834026",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2016-06",
"series_number": "6",
"volume": "21",
"issue": "6",
"pages": "Art. No. 061007"
},
{
"id": "authors:38jtt-avy27",
"collection": "authors",
"collection_id": "38jtt-avy27",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180906-155954125",
"type": "article",
"title": "Quantitative photoacoustic elastography in humans",
"author": [
{
"family_name": "Hai",
"given_name": "Pengfei",
"clpid": "Hai-Pengfei"
},
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Gong",
"given_name": "Lei",
"orcid": "0000-0002-0995-5781",
"clpid": "Gong-Lei"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We report quantitative photoacoustic elastography (QPAE) capable of measuring Young's modulus of biological tissue in vivo in humans. By combining conventional PAE with a stress sensor having known stress\u2013strain behavior, QPAE can simultaneously measure strain and stress, from which Young's modulus is calculated. We first demonstrate the feasibility of QPAE in agar phantoms with different concentrations. The measured Young's modulus values fit well with both the empirical expectation based on the agar concentrations and those measured in an independent standard compression test. Next, QPAE was applied to quantify the Young's modulus of skeletal muscle in vivo in humans, showing a linear relationship between muscle stiffness and loading. The results demonstrated the capability of QPAE to assess the absolute elasticity of biological tissue noninvasively in vivo in humans, indicating its potential for tissue biomechanics studies and clinical applications.",
"doi": "10.1117/1.JBO.21.6.066011",
"pmcid": "PMC5994997",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2016-06",
"series_number": "6",
"volume": "21",
"issue": "6",
"pages": "Art. No. 066011"
},
{
"id": "authors:bmp33-bb248",
"collection": "authors",
"collection_id": "bmp33-bb248",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-141105522",
"type": "article",
"title": "In vivo photoacoustic tomography of myoglobin oxygen saturation",
"author": [
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Myoglobin is an essential oxygen-binding hemoprotein in skeletal and cardiac muscles that buffers intracellular oxygen (O_2) concentration in response to hypoxia or elevated muscle activities. We present a method that uses photoacoustic computed tomography to measure the distribution of myoglobin in tissue and the oxygen saturation of myoglobin (sO_2-Mb). From photoacoustic measurements of mice in different oxygenation states, we performed calibration-free quantification of the sO_2 \u2013Mb change in the backbone muscle in vivo.",
"doi": "10.1117/1.JBO.21.6.061002",
"pmcid": "PMC5397140",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2016-06",
"series_number": "6",
"volume": "21",
"issue": "6",
"pages": "Art. No. 061002"
},
{
"id": "authors:7qh3y-q8q07",
"collection": "authors",
"collection_id": "7qh3y-q8q07",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180911-134031048",
"type": "article",
"title": "In vivo photoacoustic microscopy of human cuticle microvasculature with single-cell resolution",
"author": [
{
"family_name": "Hsu",
"given_name": "Hsun-Chia",
"clpid": "Hsu-Hsun-Chia"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "As a window on the microcirculation, human cuticle capillaries provide rich information about the microvasculature, such as its morphology, density, dimensions, or even blood flow speed. Many imaging technologies have been employed to image human cuticle microvasculature. However, almost none of these techniques can noninvasively observe the process of oxygen release from single red blood cells (RBCs), an observation which can be used to study healthy tissue functionalities or to diagnose, stage, or monitor diseases. For the first time, we adapted single-cell resolution photoacoustic (PA) microscopy (PA flowoxigraphy) to image cuticle capillaries and quantified multiple functional parameters. Our results show more oxygen release in the curved cuticle tip region than in other regions of a cuticle capillary loop, associated with a low of RBC flow speed in the tip region. Further analysis suggests that in addition to the RBC flow speed, other factors, such as the drop of the partial oxygen pressure in the tip region, drive RBCs to release more oxygen in the tip region.",
"doi": "10.1117/1.JBO.21.5.056004",
"pmcid": "PMC5998605",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2016-05",
"series_number": "5",
"volume": "21",
"issue": "5",
"pages": "Art. No. 056004"
},
{
"id": "authors:rg8j5-9a374",
"collection": "authors",
"collection_id": "rg8j5-9a374",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160712-102112883",
"type": "article",
"title": "Bit-efficient, sub-millisecond wavefront measurement using a lock-in camera for time-reversal based optical focusing inside scattering media",
"author": [
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Ma",
"given_name": "Cheng",
"clpid": "Ma-Cheng"
},
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Time-reversed ultrasonically encoded optical focusing measures the wavefront of ultrasonically tagged light, and then phase conjugates the tagged light back to the ultrasonic focus, thus focusing light deep inside the scattering media. In previous works, the speed of wavefront measurement was limited by the low frame rates of conventional cameras. In addition, these cameras used most of their bits to represent an informationless background when the signal-to-background ratio was low, resulting in extremely low efficiencies in the use of bits. Here, using a lock-in camera, we increase the bit efficiency and reduce the data transfer load by digitizing only the signal after rejecting the background. With this camera, we obtained the wavefront of ultrasonically tagged light after a single frame of measurement taken within 0.3 ms, and focused light in between two diffusers. The phase sensitivity has reached 0.51 rad even when the SBR is 6\u00d710^(\u22124).",
"doi": "10.1364/OL.41.001321",
"pmcid": "PMC4874255",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2016-04-01",
"series_number": "7",
"volume": "41",
"issue": "7",
"pages": "1321-1324"
},
{
"id": "authors:wjkpj-ewj61",
"collection": "authors",
"collection_id": "wjkpj-ewj61",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-150841162",
"type": "article",
"title": "Focusing light through scattering media by full-polarization digital optical phase conjugation",
"author": [
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Ma",
"given_name": "Cheng",
"clpid": "Ma-Cheng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Digital optical phase conjugation (DOPC) is an emerging technique for focusing light through or within scattering media such as biological tissue. Since DOPC systems are based on time reversal, they benefit from collecting as much information about the scattered light as possible. However, existing DOPC techniques record and subsequently phase-conjugate the scattered light in only a single-polarization state, limited by the operating principle of spatial light modulators. Here, we develop the first, to the best of our knowledge, full-polarization DOPC system that records and phase-conjugates scattered light along two orthogonal polarizations. When focusing light through thick scattering media, such as 2 mm and 4 mm-thick chicken breast tissue, our full-polarization DOPC system on average doubles the focal peak-to-background ratio achieved by single-polarization DOPC systems and improves the phase-conjugation fidelity.",
"doi": "10.1364/OL.41.001130",
"pmcid": "PMC4795172",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2016-03-15",
"series_number": "6",
"volume": "41",
"issue": "6",
"pages": "1130-1133"
},
{
"id": "authors:wcz7t-b6n41",
"collection": "authors",
"collection_id": "wcz7t-b6n41",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-143506465",
"type": "article",
"title": "Seeing Through the Surface: Non-invasive Characterization of Biomaterial-Tissue Interactions Using Photoacoustic Microscopy",
"author": [
{
"family_name": "Zhang",
"given_name": "Yu Shrike",
"clpid": "Zhang-Yu-Shrike"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "At the intersection of life sciences, materials science, engineering, and medicine, regenerative medicine stands out as a rapidly progressing field that aims at retaining, restoring, or augmenting tissue/organ functions to promote the human welfare. While the field has witnessed tremendous advancements over the past few decades, it still faces many challenges. For example, it has been difficult to visualize, monitor, and assess the functions of the engineered tissue/organ constructs, particularly when three-dimensional scaffolds are involved. Conventional approaches based on histology are invasive and therefore only convey end-point assays. The development of volumetric imaging techniques such as confocal and ultrasonic imaging has enabled direct observation of intact constructs without the need of sectioning. However, the capability of these techniques is often limited in terms of penetration depth and contrast. In comparison, the recently developed photoacoustic microscopy (PAM) has allowed us to address these issues by integrating optical and ultrasonic imaging to greatly reduce the effect of tissue scattering of photons with one-way ultrasound detection while retaining the high optical absorption contrast. PAM has been successfully applied to a number of studies, such as observation of cell distribution, monitoring of vascularization, and interrogation of biomaterial degradation. In this review article, we highlight recent progress in non-invasive and volumetric characterization of biomaterial\u2013tissue interactions using PAM. We also discuss challenges ahead and envision future directions.",
"doi": "10.1007/s10439-015-1485-2",
"pmcid": "PMC4792739",
"issn": "0090-6964",
"publisher": "Springer",
"publication": "Annals of Biomedical Engineering",
"publication_date": "2016-03",
"series_number": "3",
"volume": "44",
"issue": "3",
"pages": "649-666"
},
{
"id": "authors:jgart-5hx36",
"collection": "authors",
"collection_id": "jgart-5hx36",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-110123080",
"type": "article",
"title": "Cuffing-based photoacoustic flowmetry in humans in the optical diffusive regime",
"author": [
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Measuring blood flow speed in the optical diffusive regime in humans has been a long standing challenge for photoacoustic tomography. In this work, we proposed a cuffing-based method to quantify blood flow speed in humans with a handheld photoacoustic probe. By cuffing and releasing the blood vessel, we can measure the blood flow speed downstream. In phantom experiments, we demonstrated that the minimum and maximum measurable flow speeds were 0.035 mm/s and 42 mm/s, respectively. In human experiments, flow speeds were measured in three different blood vessels: a radial artery in the right forearm, a radial artery in the index finger of the right hand, and a radial vein in the right forearm. Taking advantage of the handheld probe, our method can potentially be used to monitor blood flow speed in the clinic and at the bedside.",
"doi": "10.1002/jbio.201500181",
"pmcid": "PMC4775313",
"issn": "1864-063X",
"publisher": "Wiley-VCH",
"publication": "Journal of Biophotonics",
"publication_date": "2016-03",
"series_number": "3",
"volume": "9",
"issue": "3",
"pages": "208-212"
},
{
"id": "authors:qfmk9-1ef25",
"collection": "authors",
"collection_id": "qfmk9-1ef25",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190228-115827049",
"type": "article",
"title": "A review of snapshot multidimensional optical imaging: Measuring photon tags in parallel",
"author": [
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Multidimensional optical imaging has seen remarkable growth in the past decade. Rather than measuring only the two-dimensional spatial distribution of light, as in conventional photography, multidimensional optical imaging captures light in up to nine dimensions, providing unprecedented information about incident photons' spatial coordinates, emittance angles, wavelength, time, and polarization. Multidimensional optical imaging can be accomplished either by scanning or parallel acquisition. Compared with scanning-based imagers, parallel acquisition\u2013also dubbed snapshot imaging\u2013has a prominent advantage in maximizing optical throughput, particularly when measuring a datacube of high dimensions. Here, we first categorize snapshot multidimensional imagers based on their acquisition and image reconstruction strategies, then highlight the snapshot advantage in the context of optical throughput, and finally we discuss their state-of-the-art implementations and applications.",
"doi": "10.1016/j.physrep.2015.12.004",
"pmcid": "PMC4846296",
"issn": "0370-1573",
"publisher": "Elsevier",
"publication": "Physics Reports",
"publication_date": "2016-02-29",
"volume": "616",
"pages": "1-37"
},
{
"id": "authors:m64y5-bpz05",
"collection": "authors",
"collection_id": "m64y5-bpz05",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160712-104213793",
"type": "article",
"title": "Photoacoustic elastography",
"author": [
{
"family_name": "Hai",
"given_name": "Pengfei",
"clpid": "Hai-Pengfei"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Li",
"given_name": "Guo",
"clpid": "Li-Guo"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Elastography can noninvasively map the elasticity distribution in biological tissue, which can potentially be used to reveal disease conditions. In this Letter, we have demonstrated photoacoustic elastography by using a linear-array photoacoustic computed tomography system. The feasibility of photoacoustic elastography was first demonstrated by imaging the strains of single-layer and bilayer gelatin phantoms with various stiffness values. The measured strains agreed well with theoretical values, with an average error of less than 5.2%. Next, in vivo photoacoustic elastography was demonstrated on a mouse leg, where the fat and muscle distribution was mapped based on the elasticity contrast. We confirmed the photoacoustic elastography results by ultrasound elastography performed simultaneously.",
"doi": "10.1364/OL.41.000725",
"pmcid": "PMC4858317",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2016-02-15",
"series_number": "4",
"volume": "41",
"issue": "4",
"pages": "725-728"
},
{
"id": "authors:fhhq9-5cy39",
"collection": "authors",
"collection_id": "fhhq9-5cy39",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-141838929",
"type": "article",
"title": "Micromachined silicon parallel acoustic delay lines as time-delayed ultrasound detector array for real-time photoacoustic tomography",
"author": [
{
"family_name": "Cho",
"given_name": "Y.",
"clpid": "Cho-Y"
},
{
"family_name": "Chang",
"given_name": "C.-C.",
"clpid": "Chang-C-C"
},
{
"family_name": "Wang",
"given_name": "L. V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Zou",
"given_name": "J.",
"clpid": "Zou-J"
}
],
"abstract": "This paper reports the development of a new 16-channel parallel acoustic delay line (PADL) array for real-time photoacoustic tomography (PAT). The PADLs were directly fabricated from single-crystalline silicon substrates using deep reactive ion etching. Compared with other acoustic delay lines (e.g., optical fibers), the micromachined silicon PADLs offer higher acoustic transmission efficiency, smaller form factor, easier assembly, and mass production capability. To demonstrate its real-time photoacoustic imaging capability, the silicon PADL array was interfaced with one single-element ultrasonic transducer followed by one channel of data acquisition electronics to receive 16 channels of photoacoustic signals simultaneously. A PAT image of an optically-absorbing target embedded in an optically-scattering phantom was reconstructed, which matched well with the actual size of the imaged target. Because the silicon PADL array allows a signal-to-channel reduction ratio of 16:1, it could significantly simplify the design and construction of ultrasonic receivers for real-time PAT.",
"doi": "10.1088/2040-8978/18/2/024003",
"issn": "2040-8978",
"publisher": "IOP Publishing",
"publication": "Journal of Optics",
"publication_date": "2016-02",
"series_number": "2",
"volume": "18",
"issue": "2",
"pages": "Art. No. 024003"
},
{
"id": "authors:j2hkw-qhr22",
"collection": "authors",
"collection_id": "j2hkw-qhr22",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180907-102835091",
"type": "article",
"title": "Photoacoustic microscopy of arteriovenous shunts and blood diffusion in early-stage tumors",
"author": [
{
"family_name": "Yeh",
"given_name": "Chenghung",
"clpid": "Yeh-Chenghung"
},
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Sohn",
"given_name": "Rebecca E.",
"clpid": "Sohn-R-E"
},
{
"family_name": "Arbeit",
"given_name": "Jeffrey M.",
"clpid": "Arbeit-J-M"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Angiogenesis in a tumor region creates arteriovenous (AV) shunts that cause an abnormal venous blood oxygen saturation (sO_2) distribution. Here, we applied optical-resolution photoacoustic microscopy to study the AV shunting in vivo. First, we built a phantom to image sO_2 distribution in a vessel containing converged flows from two upstream blood vessels with different sO_2 values. The phantom experiment showed that the blood from the two upstream vessels maintained a clear sO_2 boundary for hundreds of seconds, which is consistent with our theoretical analysis using a diffusion model. Next, we xenotransplanted O-786 tumor cells in mouse ears and observed abnormal sO_2 distribution in the downstream vein from the AV shunts in vivo. Finally, we identified the tumor location by tracing the sO_2 distribution. Our study suggests that abnormal sO_2 distribution induced by the AV shunts in the vessel network may be used as a new functional benchmark for early tumor detection.",
"doi": "10.1117/1.JBO.21.2.020501",
"pmcid": "PMC4814546",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2016-02",
"series_number": "2",
"volume": "21",
"issue": "2",
"pages": "Art. No. 020501"
},
{
"id": "authors:bgzh1-fve52",
"collection": "authors",
"collection_id": "bgzh1-fve52",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-142426142",
"type": "article",
"title": "Multiscale Functional and Molecular Photoacoustic Tomography",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) combines rich optical absorption contrast with the high spatial resolution of ultrasound at depths in tissue. The high scalability of PAT has enabled anatomical imaging of biological structures ranging from organelles to organs. The inherent functional and molecular imaging capabilities of PAT have further allowed it to measure important physiological parameters and track critical cellular activities. Integration of PAT with other imaging technologies provides complementary capabilities and can potentially accelerate the clinical translation of PAT.",
"doi": "10.1177/0161734615584312",
"pmcid": "PMC4628905",
"issn": "0161-7346",
"publisher": "SAGE",
"publication": "Ultrasonic Imaging",
"publication_date": "2016-01",
"series_number": "1",
"volume": "38",
"issue": "1",
"pages": "44-62"
},
{
"id": "authors:tmmf8-a8z75",
"collection": "authors",
"collection_id": "tmmf8-a8z75",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180907-095235653",
"type": "article",
"title": "A special year for light",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "To celebrate the contribution of optics to humankind, the UN proclaimed 2015 as the International Year of Light and Light-based Technologies. Light is truly special. The minute optical region of the vast electromagnetic spectrum is the only one that provides molecular information directly. Due to the fundamental importance of molecules to organisms, light plays a unique role in biology and medicine. Interfacing between engineering and biomedicine, biomedical optics will continue to grow in years to come and will find even greater impact in human health.",
"doi": "10.1117/1.JBO.21.1.010101",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2016-01",
"series_number": "1",
"volume": "21",
"issue": "1",
"pages": "Art. No. 010101"
},
{
"id": "authors:ggwc3-aj367",
"collection": "authors",
"collection_id": "ggwc3-aj367",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160615-094851020",
"type": "article",
"title": "Multiscale photoacoustic tomography using reversibly switchable bacterial phytochrome as a near-infrared photochromic probe",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Kaberniuk",
"given_name": "Andrii A.",
"clpid": "Kaberniuk-A-A"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Shcherbakova",
"given_name": "Daria M.",
"clpid": "Shcherbakova-D-M"
},
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Li",
"given_name": "Guo",
"clpid": "Li-Guo"
},
{
"family_name": "Verkhusha",
"given_name": "Vladislav V.",
"orcid": "0000-0002-2083-8121",
"clpid": "Verkhusha-V-V"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) of genetically encoded probes allows for imaging of targeted biological processes deep in tissues with high spatial resolution; however, high background signals from blood can limit the achievable detection sensitivity. Here we describe a reversibly switchable nonfluorescent bacterial phytochrome for use in multiscale photoacoustic imaging, BphP1, with the most red-shifted absorption among genetically encoded probes. BphP1 binds a heme-derived biliverdin chromophore and is reversibly photoconvertible between red and near-infrared light-absorption states. We combined single-wavelength PAT with efficient BphP1 photoswitching, which enabled differential imaging with substantially decreased background signals, enhanced detection sensitivity, increased penetration depth and improved spatial resolution. We monitored tumor growth and metastasis with ~100-\u03bcm resolution at depths approaching 10 mm using photoacoustic computed tomography, and we imaged individual cancer cells with a suboptical-diffraction resolution of ~140 nm using photoacoustic microscopy. This technology is promising for biomedical studies at several scales.",
"doi": "10.1038/nmeth.3656",
"pmcid": "PMC4697872",
"issn": "1548-7091",
"publisher": "Nature Publishing Group",
"publication": "Nature Methods",
"publication_date": "2016-01",
"volume": "13",
"pages": "67-73"
},
{
"id": "authors:0qssh-ap624",
"collection": "authors",
"collection_id": "0qssh-ap624",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-104137267",
"type": "article",
"title": "Photoacoustic tomography of vascular compliance in humans",
"author": [
{
"family_name": "Hai",
"given_name": "Pengfei",
"clpid": "Hai-Pengfei"
},
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Characterization of blood vessel elastic properties can help in detecting thrombosis and preventing life-threatening conditions such as acute myocardial infarction or stroke. Vascular elastic photoacoustic tomography (VE-PAT) is proposed to measure blood vessel compliance in humans. Implemented on a linear-array-based photoacoustic computed tomography system, VE-PAT can quantify blood vessel compliance changes due to simulated thrombosis and occlusion. The feasibility of the VE-PAT system was first demonstrated by measuring the strains under uniaxial loading in perfused blood vessel phantoms and quantifying their compliance changes due to the simulated thrombosis. The VE-PAT system detected a decrease in the compliances of blood vessel phantoms with simulated thrombosis, which was validated by a standard compression test. The VE-PAT system was then applied to assess blood vessel compliance in a human subject. Experimental results showed a decrease in compliance when an occlusion occurred downstream from the measurement point in the blood vessels, demonstrating VE-PAT's potential for clinical thrombosis detection.",
"doi": "10.1117/1.JBO.20.12.126008",
"pmcid": "PMC4684588",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2015-12",
"series_number": "12",
"volume": "20",
"issue": "12",
"pages": "Art. No. 126008"
},
{
"id": "authors:xb2t2-xhy85",
"collection": "authors",
"collection_id": "xb2t2-xhy85",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-145307431",
"type": "article",
"title": "A Constrained Variable Projection Reconstruction Method for Photoacoustic Computed Tomography Without Accurate Knowledge of Transducer Responses",
"author": [
{
"family_name": "Sheng",
"given_name": "Qiwei",
"clpid": "Sheng-Qiwei"
},
{
"family_name": "Wang",
"given_name": "Kun",
"clpid": "Wang-Kun"
},
{
"family_name": "Matthews",
"given_name": "Thomas P.",
"clpid": "Matthews-T-P"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
}
],
"abstract": "Photoacoustic computed tomography (PACT) is an emerging computed imaging modality that exploits optical contrast and ultrasonic detection principles to form images of the absorbed optical energy density within tissue. When the imaging system employs conventional piezoelectric ultrasonic transducers, the ideal photoacoustic (PA) signals are degraded by the transducers' acousto-electric impulse responses (EIRs) during the measurement process. If unaccounted for, this can degrade the accuracy of the reconstructed image. In principle, the effect of the EIRs on the measured PA signals can be ameliorated via deconvolution; images can be reconstructed subsequently by application of a reconstruction method that assumes an idealized EIR. Alternatively, the effect of the EIR can be incorporated into an imaging model and implicitly compensated for during reconstruction. In either case, the efficacy of the correction can be limited by errors in the assumed EIRs. In this work, a joint optimization approach to PACT image reconstruction is proposed for mitigating errors in reconstructed images that are caused by use of an inaccurate EIR. The method exploits the bi-linear nature of the imaging model and seeks to refine the measured EIR during the process of reconstructing the sought-after absorbed optical energy density. Computer-simulation and experimental studies are conducted to investigate the numerical properties of the method and demonstrate its value for mitigating image distortions and enhancing the visibility of fine structures.",
"doi": "10.1109/TMI.2015.2437356",
"pmcid": "PMC5886799",
"issn": "0278-0062",
"publisher": "IEEE",
"publication": "IEEE Transactions on Medical Imaging",
"publication_date": "2015-12",
"series_number": "12",
"volume": "34",
"issue": "12",
"pages": "2443-2458"
},
{
"id": "authors:6e479-ex353",
"collection": "authors",
"collection_id": "6e479-ex353",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160712-105815418",
"type": "article",
"title": "Bessel-beam Grueneisen relaxation photoacoustic microscopy with extended depth of field",
"author": [
{
"family_name": "Shi",
"given_name": "Junhui",
"orcid": "0000-0002-5741-2781",
"clpid": "Shi-Junhui"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Noordam",
"given_name": "Cedric",
"clpid": "Noordam-C"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The short focal depth of a Gaussian beam limits the volumetric imaging speed of optical resolution photoacoustic microscopy (OR-PAM). A Bessel beam, which is diffraction free, provides a long focal depth, but its side lobes deteriorate image quality when the Bessel beam is directly employed to excite photoacoustic (PA) signals in OR-PAM. We present a nonlinear approach based on the Grueneisen relaxation effect to suppress the side-lobe artifacts in PA imaging. This method extends the focal depth of OR-PAM and speeds up volumetric imaging. We experimentally demonstrated a 1-mm focal depth with a 7-\u03bcm lateral resolution and volumetrically imaged a carbon fiber and red blood cell samples.",
"doi": "10.1117/1.JBO.20.11.116002",
"pmcid": "PMC4672341",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2015-11",
"series_number": "11",
"volume": "20",
"issue": "11",
"pages": "Art. No. 116002"
},
{
"id": "authors:86wdk-1sp40",
"collection": "authors",
"collection_id": "86wdk-1sp40",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160712-123119085",
"type": "article",
"title": "Handheld photoacoustic probe to detect both melanoma depth and volume at high speed in vivo",
"author": [
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Li",
"given_name": "Guo",
"clpid": "Li-Guo"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Cornelius",
"given_name": "Lynn A.",
"clpid": "Cornelius-L-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We applied a linear-array-based photoacoustic probe to detect melanin-containing melanoma tumor depth and volume in nude mice in vivo. This system can image melanomas at five frames per second (fps), which is much faster than our previous handheld single transducer system (0.1 fps). We first theoretically show that, in addition to the higher frame rate, almost the entire boundary of the melanoma can be detected by the linear-array-based probe, while only the horizontal boundary could be detected by the previous system. Then we demonstrate the ability of this linear-array-based system in measuring both the depth and volume of melanoma through phantom, ex vivo, and in vivo experiments. The volume detection ability also enables us to accurately calculate the rate of growth of the tumor, which is an important parameter in quantifying the tumor activity. Our results show that this system can be used for clinical melanoma diagnosis and treatment in humans at the bedside.",
"doi": "10.1002/jbio.201400143",
"pmcid": "PMC4530093",
"issn": "1864-063X",
"publisher": "Wiley",
"publication": "Journal of Biophotonics",
"publication_date": "2015-11",
"series_number": "11-12",
"volume": "8",
"issue": "11-12",
"pages": "961-967"
},
{
"id": "authors:kqjvc-6zm45",
"collection": "authors",
"collection_id": "kqjvc-6zm45",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160712-110338182",
"type": "article",
"title": "Dual-Modality Photoacoustic and Ultrasound Imaging System for Noninvasive Sentinel Lymph Node Detection in Patients with Breast Cancer",
"author": [
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Erpelding",
"given_name": "Todd N.",
"clpid": "Erpelding-T-N"
},
{
"family_name": "Krumholz",
"given_name": "Arie",
"clpid": "Krumholz-A"
},
{
"family_name": "Ke",
"given_name": "Haixin",
"clpid": "Ke-Haixin"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Appleton",
"given_name": "Catherine",
"clpid": "Appleton-C"
},
{
"family_name": "Margenthaler",
"given_name": "Julie A.",
"clpid": "Margenthaler-J-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The detection of regional lymph node metastases is important in cancer staging as it guides the prognosis of the patient and the strategy for treatment. Sentinel lymph node biopsy (SLNB) is an accurate, less invasive alternative to axillary lymph node dissection. The sentinel lymph node hypothesis states that the pathological status of the axilla can be accurately predicted by determining the status of the first lymph nodes that drain from the primary tumor. Physicians use radio-labeled sulfur colloid and/or methylene blue dye to identify the SLN, which is most likely to contain metastatic cancer cells. However, the surgical procedure causes morbidity and associated expenses. To overcome these limitations, we developed a dual-modality photoacoustic and ultrasonic imaging system to noninvasively detect SLNs based on the accumulation of methylene blue dye. Ultimately, we aim to guide percutaneous needle biopsies and provide a minimally invasive method for axillary staging of breast cancer.",
"doi": "10.1038/srep15748",
"pmcid": "PMC4625171",
"issn": "2045-2322",
"publisher": "Nature Publishing Group",
"publication": "Scientific Reports",
"publication_date": "2015-10-29",
"volume": "5",
"pages": "Art. No. 15748"
},
{
"id": "authors:5p6z2-xvk24",
"collection": "authors",
"collection_id": "5p6z2-xvk24",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-144351526",
"type": "article",
"title": "Encrypted Three-dimensional Dynamic Imaging using Snapshot Time-of-flight Compressed Ultrafast Photography",
"author": [
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Hai",
"given_name": "Pengfei",
"clpid": "Hai-Pengfei"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Compressed ultrafast photography (CUP), a computational imaging technique, is synchronized with short-pulsed laser illumination to enable dynamic three-dimensional (3D) imaging. By leveraging the time-of-flight (ToF) information of pulsed light backscattered by the object, ToF-CUP can reconstruct a volumetric image from a single camera snapshot. In addition, the approach unites the encryption of depth data with the compressed acquisition of 3D data in a single snapshot measurement, thereby allowing efficient and secure data storage and transmission. We demonstrated high-speed 3D videography of moving objects at up to 75 volumes per second. The ToF-CUP camera was applied to track the 3D position of a live comet goldfish. We have also imaged a moving object obscured by a scattering medium.",
"doi": "10.1038/srep15504",
"pmcid": "PMC4621413",
"issn": "2045-2322",
"publisher": "Nature Publishing Group",
"publication": "Scientific Reports",
"publication_date": "2015-10-27",
"volume": "5",
"pages": "Art. No. 15504"
},
{
"id": "authors:dymv1-vve34",
"collection": "authors",
"collection_id": "dymv1-vve34",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-105116517",
"type": "article",
"title": "Single-exposure optical focusing inside scattering media using binarized time-reversed adapted perturbation",
"author": [
{
"family_name": "Ma",
"given_name": "Cheng",
"clpid": "Ma-Cheng"
},
{
"family_name": "Zhou",
"given_name": "Fengbo",
"clpid": "Zhou-Fengbo"
},
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Light scattering inhibits high-resolution optical imaging, manipulation, and therapy deep inside biological tissue by preventing focusing. To form deep foci, wavefront-shaping techniques that break the optical diffusion limit have been developed. For in vivo applications, such focusing must provide a high gain, high speed, and a high focal peak-to-background ratio. However, none of the previous techniques meet these requirements simultaneously. Here, we overcome this challenge by rapidly measuring the perturbed optical field within a single camera exposure followed by adaptively time-reversing the phase-binarized perturbation. Consequently, a phase-conjugated wavefront is synthesized within a millisecond, two orders of magnitude shorter than the digitally achieved record. We demonstrate real-time focusing in dynamic scattering media and extend laser speckle contrast imaging to new depths. The unprecedented combination of a fast response, high gain, and high focusing contrast makes this work a major stride toward in vivo deep-tissue optical imaging, manipulation, and therapy.",
"doi": "10.1364/OPTICA.2.000869",
"pmcid": "PMC6137808",
"issn": "2334-2536",
"publisher": "Optical Society of America",
"publication": "Optica",
"publication_date": "2015-10",
"series_number": "10",
"volume": "2",
"issue": "10",
"pages": "869-876"
},
{
"id": "authors:5y890-rqx17",
"collection": "authors",
"collection_id": "5y890-rqx17",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-151541870",
"type": "article",
"title": "Photoacoustic tomography imaging and estimation of oxygen saturation of hemoglobin in ocular tissue of rabbits",
"author": [
{
"family_name": "Hennen",
"given_name": "Stella N.",
"clpid": "Hennen-S-N"
},
{
"family_name": "Xing",
"given_name": "Wenxin",
"clpid": "Xing-Wenxin"
},
{
"family_name": "Shui",
"given_name": "Ying-Bo",
"clpid": "Shui-Ying-Bo"
},
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Kalishman",
"given_name": "Jennifer",
"clpid": "Kalishman-J"
},
{
"family_name": "Andrews-Kaminsky",
"given_name": "Lisa B.",
"clpid": "Andrews-Kaminsky-L-B"
},
{
"family_name": "Kass",
"given_name": "Michael A.",
"clpid": "Kass-M-A"
},
{
"family_name": "Beebe",
"given_name": "David C.",
"clpid": "Beebe-D-C"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "This study evaluated in vivo imaging capabilities and safety of qualitative monitoring of oxygen saturation of hemoglobin (sO_2) of rabbit ciliary body tissues obtained with acoustic resolution (AR) photoacoustic tomography (PAT). AR PAT was used to collect trans-scleral images from ciliary body vasculature of seven New Zealand White rabbits. The PAT sO_2 measurements were obtained under the following conditions: when systemic sO_2 as measured by pulse oximetry was between 100% and 99% (level 1); systemic sO_2 as measured by pulse oximetry was between 98% and 90% (level 2); and systemic sO_2 as measured by pulse oximetry was less than 90% (level 3). Following imaging, histological analysis of ocular tissue was conducted to evaluate for possible structural damage caused by the AR PAT imaging.\nAR PAT was able to resolve anatomical structures of the anterior segment of the eye, viewed through the cornea or anterior sclera. Histological studies revealed no ocular damage. On average, sO_2 values (%) obtained with AR PAT were lower than sO_2 values obtained with pulse oximetry (all p < 0.001): 86.28 \u00b1 4.16 versus 99.25 \u00b1 0.28, 84.09 \u00b1 1.81 vs. 95.3 \u00b1 2.6, and 64.49 \u00b1 7.27 vs. 71.15 \u00b1 10.21 for levels 1, 2 and 3 respectively. AR PAT imaging modality is capable of qualitative monitoring for deep tissue sO_2 in rabbits. Further studies are needed to validate and modify the AR PAT modality specifically for use in human eyes. Having a safe, non-invasive method of in vivo imaging of sO_2 in the anterior segment is important to studies evaluating the role of oxidative damage, hypoxia and ischemia in pathogenesis of ocular diseases.",
"doi": "10.1016/j.exer.2015.05.022",
"pmcid": "PMC5821107",
"issn": "0014-4835",
"publisher": "Elsevier",
"publication": "Experimental Eye Research",
"publication_date": "2015-09",
"volume": "138",
"pages": "153-158"
},
{
"id": "authors:7nkjv-q4e02",
"collection": "authors",
"collection_id": "7nkjv-q4e02",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-094614611",
"type": "article",
"title": "In vivo photoacoustic flowmetry at depths of the diffusive regime based on saline injection",
"author": [
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Poudel",
"given_name": "Joemini",
"clpid": "Poudel-J"
},
{
"family_name": "Li",
"given_name": "Guo",
"clpid": "Li-Guo"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We propose a saline injection-based method to quantify blood flow velocity in vivo with acoustic-resolution photoacoustic tomography. By monitoring the saline\u2013blood interface propagating in the blood vessel, the flow velocity can be resolved. We first demonstrated our method in phantom experiments, where a root mean square error of prediction of 0.29\u2009\u2009mm/s \n0.29\u2009\u2009mm/s\n was achieved. By injecting saline into a mouse tail vein covered with 1 mm chicken tissue, we showed that the flow velocity in the tail vein could be measured at depths, which is especially pertinent to monitoring blood flow velocity in patients undergoing intravenous infusion.",
"doi": "10.1117/1.JBO.20.8.087001",
"pmcid": "PMC4681378",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2015-08",
"series_number": "8",
"volume": "20",
"issue": "8",
"pages": "Art. No. 087001"
},
{
"id": "authors:sk9mc-rcr92",
"collection": "authors",
"collection_id": "sk9mc-rcr92",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-095249926",
"type": "article",
"title": "Multiview Hilbert transformation for full-view photoacoustic computed tomography using a linear array",
"author": [
{
"family_name": "Li",
"given_name": "Guo",
"clpid": "Li-Guo"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Due to their low cost, hand-held convenience, wide selection of bandwidths, and ultrasound imaging capability, linear ultrasonic transducer arrays have been widely studied for photoacoustic computed tomography (PACT). As linear-array PACT suffers from a limited view, full-view imaging requires either the transducer or the object to be rotated. So far, both the central frequencies and bandwidth of linear transducer arrays applied in full-view PACT are low, limiting the spatial resolutions of the reconstructed images. Here, we present a multiview high-frequency PACT imaging system implemented with a commercial 40-MHz central frequency linear transducer array. By rotating the object through multiple angles with respect to the linear transducer array, we acquired full-view photoacoustic pressure measurements. Further, to quantify the unipolar initial pressures and overcome the limitations of the single-view Hilbert transformation, we developed a multiview Hilbert transformation method. The in-plane spatial resolution of this full-view linear-array PACT was quantified to be isotropically 60\u2009\u03bcm within a 10\u00d710\u2009\u2009mm^2 field of view. The system was demonstrated by imaging both a leaf skeleton and a zebrafish in vivo.",
"doi": "10.1117/1.JBO.20.6.066010",
"pmcid": "PMC4481023",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2015-06",
"series_number": "6",
"volume": "20",
"issue": "6",
"pages": "Art. No. 066010"
},
{
"id": "authors:pkqyq-78t34",
"collection": "authors",
"collection_id": "pkqyq-78t34",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-085132048",
"type": "article",
"title": "Nonlinear photoacoustic spectroscopy of hemoglobin",
"author": [
{
"family_name": "Danielli",
"given_name": "Amos",
"clpid": "Danielli-A"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Favazza",
"given_name": "Christopher P.",
"clpid": "Favazza-C-P"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "As light intensity increases in photoacoustic imaging, the saturation of optical absorption and the temperature dependence of the thermal expansion coefficient result in a measurable nonlinear dependence of the photoacoustic (PA) signal on the excitation pulse fluence. Here, under controlled conditions, we investigate the intensity-dependent photoacoustic signals from oxygenated and deoxygenated hemoglobin at varied optical wavelengths and molecular concentrations. The wavelength and concentration dependencies of the nonlinear PA spectrum are found to be significantly greater in oxygenated hemoglobin than in deoxygenated hemoglobin. These effects are further influenced by the hemoglobin concentration. These nonlinear phenomena provide insights into applications of photoacoustics, such as measurements of average inter-molecular distances on a nm scale or with a tuned selection of wavelengths, a more accurate quantitative PA tomography.",
"doi": "10.1063/1.4921474",
"pmcid": "PMC4441705",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2015-05-18",
"series_number": "20",
"volume": "106",
"issue": "20",
"pages": "Art. No. 203701"
},
{
"id": "authors:nyh0n-mgm41",
"collection": "authors",
"collection_id": "nyh0n-mgm41",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191030-073034387",
"type": "article",
"title": "Photoacoustic Microscopy: Superdepth, superresolution, and superb contrast",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Song",
"given_name": "Liang",
"clpid": "Song-Liang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Since its invention in the 17th century, optical microscopy has revolutionized biomedical studies by scrutinizing the biological realm on cellular levels, taking advantage of its excellent light-focusing capability. However, most biological tissues scatter light highly. As light travels in tissue, cumulative scattering events cause the photons to lose their original propagation direction and, thus, their ability to be focused, which has largely limited the penetration depth of optical microscopy. Conventional planar optical microscopy can provide penetration of only ~100 ?m before photons begin to be scattered. The penetration of modern optical microcopy, such as confocal microscopy and multiphoton microscopy, is still limited to approximately the optical diffusion limit (~1 mm in the skin as approximated by one optical transport mean free path), where scattered photons retain a strong memory of the original propagation direction. So far, it still remains a challenge for pure optical methods to achieve high-resolution in vivo imaging beyond the diffusion limit (i.e., superdepth imaging).",
"doi": "10.1109/mpul.2015.2409100",
"issn": "2154-2287",
"publisher": "IEEE",
"publication": "IEEE Pulse",
"publication_date": "2015-05",
"series_number": "3",
"volume": "6",
"issue": "3",
"pages": "34-37"
},
{
"id": "authors:y0pce-arv83",
"collection": "authors",
"collection_id": "y0pce-arv83",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190227-100732539",
"type": "article",
"title": "Three-Dimensional Photoacoustic Endoscopic Imaging of the Rabbit Esophagus",
"author": [
{
"family_name": "Yang",
"given_name": "Joon Mo",
"clpid": "Yang-Joon-Mo"
},
{
"family_name": "Favazza",
"given_name": "Christopher",
"clpid": "Favazza-C-P"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We report photoacoustic and ultrasonic endoscopic images of two intact rabbit esophagi. To investigate the esophageal lumen structure and microvasculature, we performed in vivo and ex vivo imaging studies using a 3.8-mm diameter photoacoustic endoscope and correlated the images with histology. Several interesting anatomic structures were newly found in both the in vivo and ex vivo images, which demonstrates the potential clinical utility of this endoscopic imaging modality. In the ex vivo imaging experiment, we acquired high-resolution motion-artifact-free three-dimensional photoacoustic images of the vasculatures distributed in the walls of the esophagi and extending to the neighboring mediastinal regions. Blood vessels with apparent diameters as small as 190 \u03bcm were resolved. Moreover, by taking advantage of the dual-mode high-resolution photoacoustic and ultrasound endoscopy, we could better identify and characterize the anatomic structures of the esophageal lumen, such as the mucosal and submucosal layers in the esophageal wall, and an esophageal branch of the thoracic aorta. In this paper, we present the first photoacoustic images showing the vasculature of a vertebrate esophagus and discuss the potential clinical applications and future development of photoacoustic endoscopy.",
"doi": "10.1371/journal.pone.0120269",
"pmcid": "PMC4398324",
"issn": "1932-6203",
"publisher": "Public Library of Science",
"publication": "PLoS ONE",
"publication_date": "2015-04-15",
"series_number": "4",
"volume": "10",
"issue": "4",
"pages": "Art. No. e0120269"
},
{
"id": "authors:93bg8-w5530",
"collection": "authors",
"collection_id": "93bg8-w5530",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-105754500",
"type": "article",
"title": "Ultrasonic-heating-encoded photoacoustic tomography with virtually augmented detection view",
"author": [
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Li",
"given_name": "Guo",
"clpid": "Li-Guo"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic (PA) imaging of arbitrarily shaped or oriented objects may miss important features because PA waves propagate normal to structure boundaries and may miss the acoustic detectors when the detection view has a limited angular range. To overcome this long-standing problem, we present an ultrasonic thermal encoding approach that is universally applicable. We exploit the temperature dependence of the Grueneisen parameter and encode a voxel using heat generated by a focused ultrasonic transducer. The PA amplitude from the encoded voxel is increased while those from the neighboring voxels are unchanged. Consequently, the amplitude-increased PA waves propagate in all directions due to the round cross section of the encoded region and thus can be received at any viewing angle on the cross-sectional plane. We built a mathematical model for the thermally encoded PA tomography, performed a numerical simulation, and experimentally validated the ultrasonic thermal encoding efficiency. As a proof of concept, we demonstrate full-view in vivo vascular imaging and compare it to the original linear-array PA tomography system, showing dramatically enhanced imaging of arbitrarily oriented blood vessels. Since ultrasonic heating can be focused deeply, this method can be applied to deep tissue imaging and is promising for full-view imaging of other features of biomedical interest, such as tumor margins.",
"doi": "10.1364/OPTICA.2.000307",
"pmcid": "PMC4429303",
"issn": "2334-2536",
"publisher": "Optical Society of America",
"publication": "Optica",
"publication_date": "2015-04",
"series_number": "4",
"volume": "2",
"issue": "4",
"pages": "307-312"
},
{
"id": "authors:yb3tv-mpg69",
"collection": "authors",
"collection_id": "yb3tv-mpg69",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-153718720",
"type": "article",
"title": "Three-dimensional arbitrary trajectory scanning photoacoustic microscopy",
"author": [
{
"family_name": "Yeh",
"given_name": "Chenghung",
"clpid": "Yeh-Chenghung"
},
{
"family_name": "Soetikno",
"given_name": "Brian",
"clpid": "Soetikno-B"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have enhanced photoacoustic microscopy with three-dimensional arbitrary trajectory (3-DAT) scanning, which can rapidly image selected vessels over a large field of view (FOV) and maintain a high signal-to-noise ratio (SNR) despite the depth variation of the vessels. We showed that hemoglobin oxygen saturation (sO_2) and blood flow can be measured simultaneously in a mouse ear in vivo at a frame rate 67 times greater than that of a traditional two-dimensional raster scan. We also observed sO_2 dynamics in response to switching from systemic hypoxia to hyperoxia.",
"doi": "10.1002/jbio.201400055",
"pmcid": "PMC4312269",
"issn": "1864-063X",
"publisher": "Wiley",
"publication": "Journal of Biophotonics",
"publication_date": "2015-04",
"series_number": "4",
"volume": "8",
"issue": "4",
"pages": "303-308"
},
{
"id": "authors:q7ew5-w4w54",
"collection": "authors",
"collection_id": "q7ew5-w4w54",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160615-093234473",
"type": "article",
"title": "High-speed label-free functional photoacoustic microscopy of mouse brain in action",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Yang",
"given_name": "Joon-Mo",
"clpid": "Yang-Joon-Mo"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wong",
"given_name": "Terence T. W.",
"orcid": "0000-0001-6399-758X",
"clpid": "Wong-Terence-T-W"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Huang",
"given_name": "Chih-Hsien",
"clpid": "Huang-Chih-Hsien"
},
{
"family_name": "Zou",
"given_name": "Jun",
"orcid": "0000-0002-9543-6135",
"clpid": "Zou-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present fast functional photoacoustic microscopy (PAM) for three-dimensional high-resolution, high-speed imaging of the mouse brain, complementary to other imaging modalities. We implemented a single-wavelength pulse-width-based method with a one-dimensional imaging rate of 100 kHz to image blood oxygenation with capillary-level resolution. We applied PAM to image the vascular morphology, blood oxygenation, blood flow and oxygen metabolism in both resting and stimulated states in the mouse brain.",
"doi": "10.1038/nmeth.3336",
"pmcid": "PMC4428901",
"issn": "1548-7091",
"publisher": "Nature Publishing Group",
"publication": "Nature Methods",
"publication_date": "2015-03-30",
"series_number": "5",
"volume": "12",
"issue": "5",
"pages": "407-410"
},
{
"id": "authors:f6ehv-zbn41",
"collection": "authors",
"collection_id": "f6ehv-zbn41",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160712-105031748",
"type": "article",
"title": "Analog time-reversed ultrasonically encoded light focusing inside scattering media with a 33,000x optical power gain",
"author": [
{
"family_name": "Ma",
"given_name": "Cheng",
"clpid": "Ma-Cheng"
},
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Recent breakthrough in wavefront engineering shows great promises in controlling light propagation inside scattering media. At present, the digital approaches enjoy high gain, while their speeds are slow because of high data throughputs. In contrast, the analog approaches are intrinsically fast but suffer from poor efficiencies and small gains. Further improvements in both speed and gain are necessary to advance the existing technologies toward real-world applications. Here, we report analog time-reversal of acousto-optically tagged photons with a flux amplification of over 33,000 times (45\u2005dB) at a target location inside scattering media. Such a substantial power gain enhancement is achieved when the temporal width of the time-reversed photon packet is squeezed below the carrier-recombination-limited hologram decay time in a photorefractive crystal. Despite a focusing energy gain below unity, the unprecedented power gain is expected to enable new optical imaging, sensing, manipulation and treatment applications.",
"doi": "10.1038/srep08896",
"pmcid": "PMC4354154",
"issn": "2045-2322",
"publisher": "Nature Publishing Group",
"publication": "Scientific Reports",
"publication_date": "2015-03-10",
"volume": "5",
"pages": "Art. No. 8896"
},
{
"id": "authors:mbe73-6vy15",
"collection": "authors",
"collection_id": "mbe73-6vy15",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-102632287",
"type": "article",
"title": "Optical-resolution photoacoustic endomicroscopy in vivo",
"author": [
{
"family_name": "Yang",
"given_name": "Joon-Mo",
"clpid": "Yang-Joon-Mo"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "Rao",
"given_name": "Bin",
"orcid": "0000-0001-6494-3110",
"clpid": "Rao-Bin"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Yeh",
"given_name": "Cheng-Hung",
"clpid": "Yeh-Cheng-Hung"
},
{
"family_name": "Danielli",
"given_name": "Amos",
"clpid": "Danielli-A"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical-resolution photoacoustic microscopy (OR-PAM) has become a major experimental tool of photoacoustic tomography, with unique imaging capabilities for various biological applications. However, conventional imaging systems are all table-top embodiments, which preclude their use in internal organs. In this study, by applying the OR-PAM concept to our recently developed endoscopic technique, called photoacoustic endoscopy (PAE), we created an optical-resolution photoacoustic endomicroscopy (OR-PAEM) system, which enables internal organ imaging with a much finer resolution than conventional acoustic-resolution PAE systems. OR-PAEM has potential preclinical and clinical applications using either endogenous or exogenous contrast agents.",
"doi": "10.1364/BOE.6.000918",
"pmcid": "PMC4361445",
"issn": "2156-7085",
"publisher": "Optical Society of America",
"publication": "Biomedical Optics Express",
"publication_date": "2015-03",
"series_number": "3",
"volume": "6",
"issue": "3",
"pages": "918-932"
},
{
"id": "authors:1dg1n-24a94",
"collection": "authors",
"collection_id": "1dg1n-24a94",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-100916438",
"type": "article",
"title": "Noninvasive photoacoustic microscopy of methemoglobin in vivo",
"author": [
{
"family_name": "Tang",
"given_name": "Min",
"clpid": "Tang-Min"
},
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Due to the various causes of methemoglobinemia and its potential to be confused with other diseases, in vivo measurements of methemoglobin have significant applications in the clinic. Using photoacoustic microscopy (PAM), we quantified the average and the distributed percentage of methemoglobin both in vitro and in vivo. Based on the absorption spectra of methemoglobin, oxyhemoglobin, and deoxyhemoglobin, three wavelengths were chosen to differentiate methemoglobin from the others. The methemoglobin concentrations calculated from the photoacoustic signals agreed well with the preset concentrations. Then we imaged the methemoglobin percentage in microtubes that mimicked blood vessels. Average percentages calculated for five samples with different methemoglobin concentrations also agreed well with the preset values. Finally, we demonstrated the ability of PAM to detect methemoglobin in vivo in a mouse ear. Our results show that PAM can quantitatively image methemoglobin distribution in vivo.",
"doi": "10.1117/1.JBO.20.3.036007",
"pmcid": "PMC4356553",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2015-03",
"series_number": "3",
"volume": "20",
"issue": "3",
"pages": "Art. No. 036007"
},
{
"id": "authors:92a62-1eb76",
"collection": "authors",
"collection_id": "92a62-1eb76",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-102315185",
"type": "article",
"title": "Optical Drug Monitoring: Photoacoustic Imaging of Nanosensors to Monitor Therapeutic Lithium in Vivo",
"author": [
{
"family_name": "Cash",
"given_name": "Kevin J.",
"clpid": "Cash-K-J"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Clark",
"given_name": "Heather A.",
"clpid": "Clark-H-A"
}
],
"abstract": "Personalized medicine could revolutionize how primary care physicians treat chronic disease and how researchers study fundamental biological questions. To realize this goal, we need to develop more robust, modular tools and imaging approaches for in vivo monitoring of analytes. In this report, we demonstrate that synthetic nanosensors can measure physiologic parameters with photoacoustic contrast, and we apply that platform to continuously track lithium levels in vivo. Photoacoustic imaging achieves imaging depths that are unattainable with fluorescence or multiphoton microscopy. We validated the photoacoustic results that illustrate the superior imaging depth and quality of photoacoustic imaging with optical measurements. This powerful combination of techniques will unlock the ability to measure analyte changes in deep tissue and will open up photoacoustic imaging as a diagnostic tool for continuous physiological tracking of a wide range of analytes.",
"doi": "10.1021/nn5064858",
"pmcid": "PMC4364417",
"issn": "1936-0851",
"publisher": "American Chemical Society",
"publication": "ACS Nano",
"publication_date": "2015-02-24",
"series_number": "2",
"volume": "9",
"issue": "2",
"pages": "1692-1698"
},
{
"id": "authors:t4pxv-e5f96",
"collection": "authors",
"collection_id": "t4pxv-e5f96",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160616-112410125",
"type": "article",
"title": "Photoacoustically guided wavefront shaping for enhanced optical focusing in scattering media",
"author": [
{
"family_name": "Lai",
"given_name": "Puxiang",
"clpid": "Lai-Puxiang"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Tay",
"given_name": "Jian Wei",
"clpid": "Tay-Jian-Wei"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Non-invasively focusing light into strongly scattering media, such as biological tissue, is highly desirable but challenging. Recently, ultrasonically guided wavefront-shaping technologies have been developed to address this limitation. So far, the focusing resolution of most implementations has been limited by acoustic diffraction. Here, we introduce nonlinear photoacoustically guided wavefront shaping (PAWS), which achieves optical diffraction-limited focusing in scattering media. We develop an efficient dual-pulse excitation approach to generate strong nonlinear photoacoustic signals based on the Grueneisen relaxation effect. These nonlinear photoacoustic signals are used as feedback to guide iterative wavefront optimization. As a result, light is effectively focused to a single optical speckle grain on the scale of 5\u20137\u2005\u03bcm, which is \u223c10 times smaller than the acoustic focus, with an enhancement factor of \u223c6,000 in peak fluence. This technology has the potential to benefit many applications that require a highly confined strong optical focus in tissue.",
"doi": "10.1038/NPHOTON.2014.322",
"pmcid": "PMC4407998",
"issn": "1749-4885",
"publisher": "Nature Publishing Group",
"publication": "Nature Photonics",
"publication_date": "2015-02",
"series_number": "2",
"volume": "9",
"issue": "2",
"pages": "126-132"
},
{
"id": "authors:40c0t-8nh89",
"collection": "authors",
"collection_id": "40c0t-8nh89",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-154410593",
"type": "article",
"title": "Tripling the detection view of high-frequency linear-array-based photoacoustic computed tomography by using two planar acoustic reflectors",
"author": [
{
"family_name": "Li",
"given_name": "Guo",
"clpid": "Li-Guo"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Wang",
"given_name": "Kun",
"clpid": "Wang-Kun"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Background: Linear-array-based photoacoustic computed tomography (PACT) suffers from a limited view. Circular scanning does increase the detection view angle but is time-consuming. Therefore, it is desirable to increase the detection view angle of linear-array-based PACT without sacrificing imaging speed.\nMethods: Two planar acoustic reflectors placed at 120 degrees to each other were added to a linear-array-based PACT system. Each reflector redirects originally undetectable photoacoustic waves back to the transducer array elements, and together they triple the original detection view angle of the PACT system.\nResults: Adding two reflectors increased the detection view angle from 80 to 240 degrees. As a comparison, a single-reflector PACT has a detection view angle of only 160 degrees. A leaf skeleton phantom with a rich vascular network was imaged with the double-reflector PACT, and most of its features were recovered.\nConclusions: The two acoustic reflectors triple the detection view angle of a linear-array-based PACT without compromising the original imaging speed. This nearly full-view detection capability produces higher-quality images than single-reflector PACT or conventional PACT without reflectors.",
"doi": "10.3978/j.issn.2223-4292.2014.11.09",
"pmcid": "PMC4312304",
"issn": "2223-4306",
"publisher": "AME Publishing Company",
"publication": "Quantitative Imaging in Medicine and Surgery",
"publication_date": "2015-02",
"series_number": "1",
"volume": "5",
"issue": "1",
"pages": "57-62"
},
{
"id": "authors:kh49c-ktj35",
"collection": "authors",
"collection_id": "kh49c-ktj35",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160614-105454830",
"type": "article",
"title": "Optical focusing deep inside dynamic scattering media with near-infrared time-reversed ultrasonically encoded (TRUE) light",
"author": [
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Lai",
"given_name": "Puxiang",
"clpid": "Lai-Puxiang"
},
{
"family_name": "Ma",
"given_name": "Cheng",
"clpid": "Ma-Cheng"
},
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Grabar",
"given_name": "Alexander A.",
"clpid": "Grabar-A-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Focusing light deep inside living tissue has not been achieved despite its promise to play a central role in biomedical imaging, optical manipulation and therapy. To address this challenge, internal-guide-star-based wavefront engineering techniques\u2014for example, time-reversed ultrasonically encoded (TRUE) optical focusing\u2014were developed. The speeds of these techniques, however, were limited to no greater than 1\u2009Hz, preventing them from in vivo applications. Here we improve the speed of optical focusing deep inside scattering media by two orders of magnitude, and focus diffuse light inside a dynamic scattering medium having a speckle correlation time as short as 5.6\u2009ms, typical of living tissue. By imaging a target, we demonstrate the first focusing of diffuse light inside a dynamic scattering medium containing living tissue. Since the achieved focusing speed approaches the tissue decorrelation rate, this work is an important step towards in vivo deep tissue noninvasive optical imaging, optogenetics and photodynamic therapy.",
"doi": "10.1038/ncomms6904",
"pmcid": "PMC4477952",
"issn": "2041-1723",
"publisher": "Nature Publishing Group",
"publication": "Nature Communications",
"publication_date": "2015-01-05",
"volume": "6",
"pages": "Art. No. 5904"
},
{
"id": "authors:d2qp1-xds21",
"collection": "authors",
"collection_id": "d2qp1-xds21",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190228-115827730",
"type": "article",
"title": "\u03b1_\u03bd\u03b2_3-targeted Copper Nanoparticles Incorporating an Sn 2 Lipase-Labile Fumagillin Prodrug for Photoacoustic Neovascular Imaging and Treatment",
"author": [
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Pan",
"given_name": "Dipanjan",
"clpid": "Pan-Dipanjan"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Yang",
"given_name": "Xiaoxia",
"clpid": "Yang-Xiaoxia"
},
{
"family_name": "Senpan",
"given_name": "Angana",
"clpid": "Senpan-A"
},
{
"family_name": "Allen",
"given_name": "John S.",
"clpid": "Allen-J-S"
},
{
"family_name": "Lanza",
"given_name": "Gregory M.",
"clpid": "Lanza-G-M"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic (PA) tomography enables multiscale, multicontrast and high-resolution imaging of biological structures. In particular, contrast-enhanced PA imaging offers high-sensitivity noninvasive imaging of neovessel sprout formation and nascent tubules, which are important biomarkers of malignant tumors and progressive atherosclerotic disease. While gold nanoparticles or nanorods have been used as PA contrast agents, we utilized high-density copper oleate small molecules encapsulated within a phospholipid surfactant (CuNPs) to generate a soft nanoparticle with PA contrast comparable to that from gold. Within the NIR window, the copper nanoparticles provided a 4-fold higher signal than that of blood. \u0391_\u03bd\u03b2_3-integrin targeting of CuNPs in a Matrigel\u2122 angiogenesis mouse model demonstrated prominent (p<0.05) PA contrast enhancement of the neovasculature compared with mice given nontargeted or competitively inhibited CuNPs. Furthermore, incorporation of a Sn 2 lipase-labile fumagillin prodrug into the CuNP outer lipid membrane produced marked antiangiogenesis in the same model when targeted to the \u03b1_\u03bd\u03b2_3-integrin, providing proof of concept in vivo for the first targeted PA - drug delivery agent.",
"doi": "10.7150/thno.10014",
"pmcid": "PMC4278999",
"issn": "1838-7640",
"publisher": "Ivyspring International Publisher",
"publication": "Theranostics",
"publication_date": "2015-01-01",
"series_number": "2",
"volume": "5",
"issue": "2",
"pages": "124-133"
},
{
"id": "authors:218vm-3af89",
"collection": "authors",
"collection_id": "218vm-3af89",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160712-155450251",
"type": "article",
"title": "In vivo deep brain imaging of rats using oral-cavity illuminated photoacoustic computed tomography",
"author": [
{
"family_name": "Lin",
"given_name": "Li",
"orcid": "0000-0002-0517-8436",
"clpid": "Lin-Li"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Wong",
"given_name": "Terence T. W.",
"orcid": "0000-0001-6399-758X",
"clpid": "Wong-Terence-T-W"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Using internal illumination with an optical fiber in the oral cavity, we demonstrate, for the first time, photoacoustic computed tomography (PACT) of the deep brain of rats in vivo. The experiment was performed on a full-ring-array PACT system, with the capability of providing high-speed cross-sectional imaging of the brain. Compared with external illumination through the cranial skull, internal illumination delivers more light to the base of the brain. Consequently, in vivo photoacoustic images clearly reveal deep brain structures such as the hypothalamus, brain stem, and cerebral medulla.",
"doi": "10.1117/1.JBO.20.1.016019",
"pmcid": "PMC4302266",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2015-01",
"series_number": "1",
"volume": "20",
"issue": "1",
"pages": "Art. No. 016019"
},
{
"id": "authors:jntr8-n7g79",
"collection": "authors",
"collection_id": "jntr8-n7g79",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160614-102659424",
"type": "article",
"title": "Single-shot compressed ultrafast photography at one hundred billion frames per second",
"author": [
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The capture of transient scenes at high imaging speed has been long sought by photographers, with early examples being the well known recording in 1878 of a horse in motion and the 1887 photograph of a supersonic bullet. However, not until the late twentieth century were breakthroughs achieved in demonstrating ultrahigh-speed imaging (more than 10^5 frames per second). In particular, the introduction of electronic imaging sensors based on the charge-coupled device (CCD) or complementary metal\u2013oxide\u2013semiconductor (CMOS) technology revolutionized high-speed photography, enabling acquisition rates of up to 10^7 frames per second. Despite these sensors' widespread impact, further increasing frame rates using CCD or CMOS technology is fundamentally limited by their on-chip storage and electronic readout speed. Here we demonstrate a two-dimensional dynamic imaging technique, compressed ultrafast photography (CUP), which can capture non-repetitive time-evolving events at up to 10^(11) frames per second. Compared with existing ultrafast imaging techniques, CUP has the prominent advantage of measuring an x\u2013y\u2013t (x, y, spatial coordinates; t, time) scene with a single camera snapshot, thereby allowing observation of transient events with temporal resolution as tens of picoseconds. Furthermore, akin to traditional photography, CUP is receive-only, and so does not need the specialized active illumination required by other single-shot ultrafast imagers. As a result, CUP can image a variety of luminescent\u2014such as fluorescent or bioluminescent\u2014objects. Using CUP, we visualize four fundamental physical phenomena with single laser shots only: laser pulse reflection and refraction, photon racing in two media, and faster-than-light propagation of non-information (that is, motion that appears faster than the speed of light but cannot convey information). Given CUP's capability, we expect it to find widespread applications in both fundamental and applied sciences, including biomedical research.",
"doi": "10.1038/nature14005",
"pmcid": "PMC4270006",
"issn": "0028-0836",
"publisher": "Nature Publishing Group",
"publication": "Nature",
"publication_date": "2014-12-04",
"series_number": "7529",
"volume": "516",
"issue": "7529",
"pages": "74-77"
},
{
"id": "authors:j24bp-29708",
"collection": "authors",
"collection_id": "j24bp-29708",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-085051001",
"type": "article",
"title": "Time-reversed adapted-perturbation (TRAP) optical focusing onto dynamic objects inside scattering media",
"author": [
{
"family_name": "Ma",
"given_name": "Cheng",
"clpid": "Ma-Cheng"
},
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The ability to steer and focus light inside scattering media has long been sought for a multitude of applications. At present, the only feasible strategy to form optical foci inside scattering media is to guide photons by using either implanted or virtual guide stars, which can be inconvenient and limits the potential applications. Here we report a scheme for focusing light inside scattering media by employing intrinsic dynamics as guide stars. By adaptively time-reversing the perturbed component of the scattered light, we show that it is possible to focus light to the origin of the perturbation. Using this approach, we demonstrate non-invasive dynamic light focusing onto moving targets and imaging of a time-variant object obscured by highly scattering media. Anticipated applications include imaging and photoablation of angiogenic vessels in tumours, as well as other biomedical uses.",
"doi": "10.1038/NPHOTON.2014.251",
"pmcid": "PMC4266563",
"issn": "1749-4885",
"publisher": "Nature Publishing Group",
"publication": "Nature Photonics",
"publication_date": "2014-12",
"series_number": "12",
"volume": "8",
"issue": "12",
"pages": "931-936"
},
{
"id": "authors:gr1e2-v7s72",
"collection": "authors",
"collection_id": "gr1e2-v7s72",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-084430679",
"type": "article",
"title": "Frequency-swept time-reversed ultrasonically encoded optical focusing",
"author": [
{
"family_name": "Suzuki",
"given_name": "Yuta",
"clpid": "Suzuki-Yuta"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A technique to rapidly scan an optical focus inside a turbid medium is attractive for various biomedical applications. Time-reversed ultrasonically encoded (TRUE) optical focusing has previously demonstrated light focusing into a turbid medium, using both analog and digital devices. Although the digital implementation can generate a focus with high energy, it has been time consuming to scan the TRUE focus inside a sample. Here, by sweeping the frequencies of both ultrasound and light, we demonstrate a multiplex recording of ultrasonically encoded wavefronts, accelerating the generation of multiple TRUE foci. Using this technique, we obtained a 2-D image of a fluorescent target centered inside a turbid sample having a thickness of 2.4 transport mean free paths.",
"doi": "10.1063/1.4901955",
"pmcid": "PMC4235623",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2014-11-10",
"series_number": "19",
"volume": "105",
"issue": "19",
"pages": "Art. No. 191108"
},
{
"id": "authors:5dywk-x5805",
"collection": "authors",
"collection_id": "5dywk-x5805",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-143115806",
"type": "article",
"title": "Photoacoustic lymphatic imaging with high spatial-temporal resolution",
"author": [
{
"family_name": "Martel",
"given_name": "Catherine",
"clpid": "Martel-C"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Huang",
"given_name": "Chih-Hsien",
"clpid": "Huang-Chih-Hsien"
},
{
"family_name": "Zou",
"given_name": "Jun",
"orcid": "0000-0002-9543-6135",
"clpid": "Zou-Jun"
},
{
"family_name": "Randolph",
"given_name": "Gwendalyn J.",
"clpid": "Randolph-G-J"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Despite its critical function in coordinating the egress of inflammatory and immune cells out of tissues and maintaining fluid balance, the causative role of lymphatic network dysfunction in pathological settings is still understudied. Engineered-animal models and better noninvasive high spatial-temporal resolution imaging techniques in both preclinical and clinical studies will help to improve our understanding of different lymphatic-related pathologic disorders. Our aim was to take advantage of our newly optimized noninvasive wide-field fast-scanning photoacoustic (PA) microcopy system to coordinately image the lymphatic vasculature and its flow dynamics, while maintaining high resolution and detection sensitivity. Here, by combining the optical-resolution PA microscopy with a fast-scanning water-immersible microelectromechanical system scanning mirror, we have imaged the lymph dynamics over a large field-of-view, with high spatial resolution and advanced detection sensitivity. Depending on the application, lymphatic vessels (LV) were spectrally or temporally differentiated from blood vessels. Validation experiments were performed on phantoms and in vivo to identify the LV. Lymphatic flow dynamics in nonpathological and pathological conditions were also visualized. These results indicate that our newly developed PA microscopy is a promising tool for lymphatic-related biological research.",
"doi": "10.1117/1.JBO.19.11.116009",
"pmcid": "PMC4407768",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2014-11",
"series_number": "11",
"volume": "19",
"issue": "11",
"pages": "Art. No. 116009"
},
{
"id": "authors:5tq54-dee87",
"collection": "authors",
"collection_id": "5tq54-dee87",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160616-082234182",
"type": "article",
"title": "Grueneisen Relaxation Photoacoustic Microscopy",
"author": [
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The temperature-dependent property of the Grueneisen parameter has been employed in photoacoustic imaging mainly to measure tissue temperature. Here we explore this property using a different approach and develop Grueneisen relaxation photoacoustic microscopy (GR-PAM), a technique that images nonradiative absorption with confocal optical resolution. GR-PAM sequentially delivers two identical laser pulses with a microsecond-scale time delay. The first laser pulse generates a photoacoustic signal and thermally tags the in-focus absorbers. When the second laser pulse excites the tagged absorbers within the thermal relaxation time, a photoacoustic signal stronger than the first one is produced, owing to the temperature dependence of the Grueneisen parameter. GR-PAM detects the amplitude difference between the two colocated photoacoustic signals, confocally imaging the nonradiative absorption. We greatly improved axial resolution from 45\u2009\u03bcm to 2.3\u2009\u03bcm and, at the same time, slightly improved lateral resolution from 0.63\u2009\u03bcm to 0.41\u2009\u03bcm. In addition, the optical sectioning capability facilitates the measurement of the absolute absorption coefficient without fluence calibration.",
"doi": "10.1103/PhysRevLett.113.174301",
"pmcid": "PMC4287460",
"issn": "0031-9007",
"publisher": "American Physical Society",
"publication": "Physical Review Letters",
"publication_date": "2014-10-24",
"series_number": "17",
"volume": "113",
"issue": "17",
"pages": "Art. No. 174301"
},
{
"id": "authors:2hdke-b4f60",
"collection": "authors",
"collection_id": "2hdke-b4f60",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-100831735",
"type": "article",
"title": "Multiview optical resolution photoacoustic microscopy",
"author": [
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical resolution photoacoustic microscopy (OR-PAM), while providing high lateral resolution, has been limited by its relatively poor acoustically determined axial resolution. Although this limitation has been tackled in recent works by using either broadband acoustic detection or nonlinear photoacoustic effects, a flexible solution with three-dimensional optical resolution in reflection mode remains desired. Herein we present a multiview OR-PAM technique. By imaging the sample from multiple view angles and reconstructing the data using a multiview deconvolution method, we have experimentally demonstrated an isotropic optical resolution in three dimensions.",
"doi": "10.1364/OPTICA.1.000217",
"pmcid": "PMC4280660",
"issn": "2334-2536",
"publisher": "Optical Society of America",
"publication": "Optica",
"publication_date": "2014-10-20",
"series_number": "4",
"volume": "1",
"issue": "4",
"pages": "217-222"
},
{
"id": "authors:yk2k7-cqc14",
"collection": "authors",
"collection_id": "yk2k7-cqc14",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-110713188",
"type": "article",
"title": "Amplitude-masked photoacoustic wavefront shaping and application in flowmetry",
"author": [
{
"family_name": "Tay",
"given_name": "Jian Wei",
"clpid": "Tay-Jian-Wei"
},
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical-resolution photoacoustic flowmetry (PAF) allows noninvasive single-cell flow measurements. However, its operational depth is limited by optical diffusion, which prevents focusing beyond shallow depths in scattering media, as well as reducing the measurement signal-to-noise ratio (SNR). To overcome this limitation, we used binary-amplitude wavefront shaping to enhance light focusing in the presence of scattering. Here, the transmission modes that contributed constructively to the intensity at the optical focus were identified and selectively illuminated, resulting in a 14-fold intensity increase and a corresponding increase in SNR. This technique can potentially extend the operational depth of optical-resolution PAF beyond 1 mm in tissue.",
"doi": "10.1364/OL.39.005499",
"pmcid": "PMC4217128",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2014-10-01",
"series_number": "19",
"volume": "39",
"issue": "19",
"pages": "5499-5502"
},
{
"id": "authors:kzzjf-rtv11",
"collection": "authors",
"collection_id": "kzzjf-rtv11",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-093322533",
"type": "article",
"title": "Microvascular quantification based on contour-scanning photoacoustic microscopy",
"author": [
{
"family_name": "Yeh",
"given_name": "Chenghung",
"clpid": "Yeh-Chenghung"
},
{
"family_name": "Soetikno",
"given_name": "Brian",
"clpid": "Soetikno-B"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Accurate quantification of microvasculature remains of interest in fundamental pathophysiological studies and clinical trials. Current photoacoustic microscopy can noninvasively quantify properties of the microvasculature, including vessel density and diameter, with a high spatial resolution. However, the depth range of focus (i.e., focal zone) of optical-resolution photoacoustic microscopy (OR-PAM) is often insufficient to encompass the depth variations of features of interest\u2014such as blood vessels\u2014due to uneven tissue surfaces. Thus, time-consuming image acquisitions at multiple different focal planes are required to maintain the region of interest in the focal zone. We have developed continuous three-dimensional motorized contour-scanning OR-PAM, which enables real-time adjustment of the focal plane to track the vessels' profile. We have experimentally demonstrated that contour scanning improves the signal-to-noise ratio of conventional OR-PAM by as much as 41% and shortens the image acquisition time by 3.2 times. Moreover, contour-scanning OR-PAM more accurately quantifies vessel density and diameter, and has been applied to studying tumors with uneven surfaces.",
"doi": "10.1117/1.JBO.19.9.096011",
"pmcid": "PMC4164706",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2014-09-15",
"series_number": "9",
"volume": "19",
"issue": "9",
"pages": "Art. No. 096011"
},
{
"id": "authors:hbhw5-ev204",
"collection": "authors",
"collection_id": "hbhw5-ev204",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-103159834",
"type": "article",
"title": "Near-infrared optical-resolution photoacoustic microscopy",
"author": [
{
"family_name": "Hai",
"given_name": "Pengfei",
"clpid": "Hai-Pengfei"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Compared with visible light (380\u2013700 nm), near-infrared light (700\u20131400 nm) undergoes weaker optical attenuation in biological tissue; thus, it can penetrate deeper. Herein, we demonstrate near-infrared optical-resolution photoacoustic microscopy (NIR-OR-PAM) with 1046 nm illumination. A penetration depth of 3.2 mm was achieved in chicken breast tissue ex vivo using optical fluence within the American National Standards Institute (ANSI) limit (100\u2009\u2009mJ/cm^2). Beyond \u223c0.6\u2009\u2009mm deep in chicken breast tissue, NIR-OR-PAM has shown finer resolution than the visible counterpart with 570 nm illumination. The deep imaging capability of NIR-OR-PAM was validated in both a mouse ear and a mouse brain. NIR-OR-PAM of possible lipid contrast was explored as well.",
"doi": "10.1364/OL.39.005192",
"pmcid": "PMC4161671",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2014-09-01",
"series_number": "17",
"volume": "39",
"issue": "17",
"pages": "5192-5195"
},
{
"id": "authors:0hw00-gg566",
"collection": "authors",
"collection_id": "0hw00-gg566",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-152848418",
"type": "article",
"title": "Handheld photoacoustic microscopy to detect melanoma depth in vivo",
"author": [
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Xing",
"given_name": "Wenxin",
"clpid": "Xing-Wenxin"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Cornelius",
"given_name": "Lynn A.",
"clpid": "Cornelius-L-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We developed handheld photoacoustic microscopy (PAM) to detect melanoma and determine tumor depth in nude mice in vivo. Compared to our previous PAM system for melanoma imaging, a new light delivery mechanism is introduced to improve light penetration. We show that melanomas with 4.1 and 3.7 mm thicknesses can be successfully detected in phantom and in in vivo experiments, respectively. With its deep melanoma imaging ability and handheld design, this system can be tested for clinical melanoma diagnosis, prognosis, and surgical planning for patients at the bedside.",
"doi": "10.1364/OL.39.004731",
"pmcid": "PMC4160823",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2014-08-15",
"series_number": "16",
"volume": "39",
"issue": "16",
"pages": "4731-4734"
},
{
"id": "authors:1vacj-jpb03",
"collection": "authors",
"collection_id": "1vacj-jpb03",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-090334486",
"type": "article",
"title": "Label-free photoacoustic nanoscopy",
"author": [
{
"family_name": "Danielli",
"given_name": "Amos",
"clpid": "Danielli-A"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Winkler",
"given_name": "Amy M.",
"clpid": "Winkler-A-M"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Chen",
"given_name": "Yun",
"clpid": "Chen-Yun"
},
{
"family_name": "Dorn",
"given_name": "Gerald W., II",
"clpid": "Dorn-G-W-II"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Super-resolution microscopy techniques\u2014capable of overcoming the diffraction limit of light\u2014have opened new opportunities to explore subcellular structures and dynamics not resolvable in conventional far-field microscopy. However, relying on staining with exogenous fluorescent markers, these techniques can sometimes introduce undesired artifacts to the image, mainly due to large tagging agent sizes and insufficient or variable labeling densities. By contrast, the use of endogenous pigments allows imaging of the intrinsic structures of biological samples with unaltered molecular constituents. Here, we report label-free photoacoustic (PA) nanoscopy, which is exquisitely sensitive to optical absorption, with an 88 nm resolution. At each scanning position, multiple PA signals are successively excited with increasing laser pulse energy. Because of optical saturation or nonlinear thermal expansion, the PA amplitude depends on the nonlinear incident optical fluence. The high-order dependence, quantified by polynomial fitting, provides super-resolution imaging with optical sectioning. PA nanoscopy is capable of super-resolution imaging of either fluorescent or nonfluorescent molecules.",
"doi": "10.1117/1.JBO.19.8.086006",
"pmcid": "PMC4125341",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2014-08",
"series_number": "8",
"volume": "19",
"issue": "8",
"pages": "Art. No. 086006"
},
{
"id": "authors:0w0jc-xw255",
"collection": "authors",
"collection_id": "0w0jc-xw255",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-155306524",
"type": "article",
"title": "Handheld photoacoustic tomography probe built using optical-fiber parallel acoustic delay lines",
"author": [
{
"family_name": "Cho",
"given_name": "Young",
"clpid": "Cho-Young"
},
{
"family_name": "Chang",
"given_name": "Cheng-Chung",
"clpid": "Chang-Cheng-Chung"
},
{
"family_name": "Yu",
"given_name": "Jaesok",
"clpid": "Yu-Jaesok"
},
{
"family_name": "Jeon",
"given_name": "Mansik",
"clpid": "Jeon-Mansik"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Zou",
"given_name": "Jun",
"orcid": "0000-0002-9543-6135",
"clpid": "Zou-Jun"
}
],
"abstract": "The development of the first miniaturized parallel acoustic delay line (PADL) probe for handheld photoacoustic tomography (PAT) is reported. Using fused-silica optical fibers with low acoustic attenuation, we constructed two arrays of eight PADLs. Precision laser micromachining was conducted to produce robust and accurate mechanical support and alignment structures for the PADLs, with minimal acoustic distortion and interchannel coupling. The 16 optical-fiber PADLs, each with a different time delay, were arranged to form one input port and two output ports. A handheld PADL probe was constructed using two single-element transducers and two data acquisition channels (equal to a channel reduction ratio of 8:1). Photoacoustic (PA) images of a black-ink target embedded in an optically scattering phantom were successfully acquired. After traveling through the PADLs, the eight channels of differently time-delayed PA signals reached each single-element ultrasonic transducer in a designated nonoverlapping time series, allowing clear signal separation for PA image reconstruction. Our results show that the PADL technique and the handheld probe can potentially enable real-time PAT, while significantly reducing the complexity and cost of the ultrasound receiver system.",
"doi": "10.1117/1.JBO.19.8.086007",
"pmcid": "PMC4407766",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2014-08",
"series_number": "8",
"volume": "19",
"issue": "8",
"pages": "Art. No. 086007"
},
{
"id": "authors:ffm91-fb775",
"collection": "authors",
"collection_id": "ffm91-fb775",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-091859424",
"type": "article",
"title": "Microcirculatory changes identified by photoacoustic microscopy in patients with complex regional pain syndrome type I after stellate ganglion blocks",
"author": [
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Yi",
"given_name": "Xiaobin",
"clpid": "Yi-Xiaobin"
},
{
"family_name": "Xing",
"given_name": "Wenxin",
"clpid": "Xing-Wenxin"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Complex regional pain syndrome (CRPS) is a chronic pain syndrome that causes intractable pain, disability, and poor quality of life for patients. The etiology and pathophysiology of CRPS are still poorly understood. Due to a lack of proper diagnostic tools, the prognosis of CRPS is primarily based on clinical observation. The objective of this work is to evaluate a new imaging modality, photoacoustic microscopy (PAM), for assisting diagnoses and monitoring the progress and treatment outcome of CRPS. Blood vasculature and oxygen saturation (sO_2) were imaged by PAM from eight adult patients with CRPS-1. Patients' hands and cuticles were imaged both before and after stellate ganglion block (SGB) for comparison. For all patients, both vascular structure and sO_2 could be assessed by PAM. In addition, more vessels and stronger signals were observed after SGB. The results show that PAM can help diagnose and monitor CRPS.",
"doi": "10.1117/1.JBO.19.8.086017",
"pmcid": "PMC4407664",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2014-08",
"series_number": "8",
"volume": "19",
"issue": "8",
"pages": "Art. No. 086017"
},
{
"id": "authors:rcs8n-h8327",
"collection": "authors",
"collection_id": "rcs8n-h8327",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-132527952",
"type": "article",
"title": "Optical-Resolution Photoacoustic Microscopy for Volumetric and Spectral Analysis of Histological and Immunochemical Samples",
"author": [
{
"family_name": "Zhang",
"given_name": "Yu Shrike",
"clpid": "Zhang-Yu-Shrike"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "Optical-resolution photoacoustic microscopy (OR-PAM) is an imaging modality with superb penetration depth and excellent absorption contrast. Here we demonstrate, for the first time, that this technique can advance quantitative analysis of conventional chromogenic histochemistry. Because OR-PAM can quantify the absorption contrast at different wavelengths, it is feasible to spectrally resolve the specific biomolecules involved in a staining color. Furthermore, the tomographic capability of OR-PAM allows for noninvasive volumetric imaging of a thick sample without microtoming it. By immunostaining the sample with different chromogenic agents, we further demonstrated the ability of OR-PAM to resolve different types of cells in a coculture sample with imaging depths up to 1\u2005mm. Taken together, the integration of OR-PAM with (immuno)histochemistry offers a simple and versatile technique with broad applications in cell biology, pathology, tissue engineering, and related biomedical studies.",
"doi": "10.1002/anie.201403812",
"pmcid": "PMC4116434",
"issn": "1433-7851",
"publisher": "Wiley",
"publication": "Angewandte Chemie International Edition",
"publication_date": "2014-07-28",
"series_number": "31",
"volume": "53",
"issue": "31",
"pages": "8099-8103"
},
{
"id": "authors:sv3wd-v4p44",
"collection": "authors",
"collection_id": "sv3wd-v4p44",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160726-102558366",
"type": "article",
"title": "Ultralong photonic nanojet formed by a two-layer dielectric microsphere",
"author": [
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Shen",
"given_name": "Jung-Tsung",
"clpid": "Shen-Jung-Tsung"
}
],
"abstract": "A photonic nanojet is a highly focused optical beam with a subwavelength waist on the shadow side of the sphere. Successful far-field applications require long nanojets that extend afar. Using the exact Mie theory, we show that ultralong nanojets can be generated using a simple two-layer microsphere structure, using conventional optical materials that are readily available. In particular, we show that for a glass-based two-layer microsphere, the nanojet has an extension of 22 wavelengths. We also show that long nanojets can be formed using semiconductors at infrared frequencies in free space.",
"doi": "10.1364/OL.39.004120",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2014-07-15",
"series_number": "14",
"volume": "39",
"issue": "14",
"pages": "4120-4123"
},
{
"id": "authors:nhejt-kvt53",
"collection": "authors",
"collection_id": "nhejt-kvt53",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-081950398",
"type": "article",
"title": "In vivo optically encoded photoacoustic flowgraphy",
"author": [
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Yeh",
"given_name": "Cheng-Hung",
"clpid": "Yeh-Cheng-Hung"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present an optically encoded photoacoustic (PA) flow imaging method based on optical-resolution PA microscopy. An intensity-modulated continuous-wave laser photothermally encodes the flowing medium, and a pulsed laser generates PA waves to image the encoded heat pattern. Flow speeds can be calculated by cross correlation. The method was validated in phantoms at flow speeds ranging from 0.23 to 11\u2009\u2009mm/s. Venous blood flow speed in a mouse ear was also measured.",
"doi": "10.1364/OL.39.003814",
"pmcid": "PMC4165860",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2014-07-01",
"series_number": "13",
"volume": "39",
"issue": "13",
"pages": "3814-3817"
},
{
"id": "authors:bt208-man82",
"collection": "authors",
"collection_id": "bt208-man82",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180905-074318428",
"type": "article",
"title": "Combining elastography and OCT",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Researchers at University of Washington (USA) have developed a new diagnostic procedure combining elastography and optical coherence tomography (OCT) that improves the accurate assessment of in vivo tissue stiffness, often an indicator of disease.\n\nElastography aims to noninvasively and quantitatively assess the mechanical properties of soft tissues to complement structural imaging. Extensive research has been conducted in the past 15 years to develop elastography methods based on OCT. With its micron-scale resolution and submicron-scale sensitivity, OCT is envisioned in particular for elastography of ocular tissues but could also be applied to skin layers or vascular walls.",
"doi": "10.1117/2.4201407.29",
"issn": "1994-4403",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "SPIE Professional",
"publication_date": "2014-07"
},
{
"id": "authors:tg219-zjg38",
"collection": "authors",
"collection_id": "tg219-zjg38",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-134806700",
"type": "article",
"title": "Photoacoustic brain imaging: from microscopic to macroscopic scales",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Human brain mapping has become one of the most exciting contemporary research areas, with major breakthroughs expected in the coming decades. Modern brain imaging techniques have allowed neuroscientists to gather a wealth of anatomic and functional information about the brain. Among these techniques, by virtue of its rich optical absorption contrast, high spatial and temporal resolutions, and deep penetration, photoacoustic tomography (PAT) has attracted more and more attention, and is playing an increasingly important role in brain studies. In particular, PAT complements other brain imaging modalities by providing high-resolution functional and metabolic imaging. More importantly, PAT's unique scalability enables scrutinizing the brain at both microscopic and macroscopic scales, using the same imaging contrast. In this review, we present the state-of-the-art PAT techniques for brain imaging, summarize representative neuroscience applications, outline the technical challenges in translating PAT to human brain imaging, and envision potential technological deliverables.",
"doi": "10.1117/1.NPh.1.1.011003",
"pmcid": "PMC4232215",
"issn": "2329-423X",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Neurophotonics",
"publication_date": "2014-07",
"series_number": "1",
"volume": "1",
"issue": "1",
"pages": "Art. No. 011003"
},
{
"id": "authors:b7zva-b0457",
"collection": "authors",
"collection_id": "b7zva-b0457",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-095305938",
"type": "article",
"title": "Photoacoustic Microscopy and Computed Tomography: From Bench to Bedside",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
}
],
"abstract": "Photoacoustic imaging (PAI) of biological tissue has seen immense growth in the past decade, providing unprecedented spatial resolution and functional information at depths in the optical diffusive regime. PAI uniquely combines the advantages of optical excitation and those of acoustic detection. The hybrid imaging modality features high sensitivity to optical absorption and wide scalability of spatial resolution with the desired imaging depth. Here we first summarize the fundamental principles underpinning the technology, then highlight its practical implementation, and finally discuss recent advances toward clinical translation.",
"doi": "10.1146/annurev-bioeng-071813-104553",
"pmcid": "PMC4102891",
"issn": "1523-9829",
"publisher": "Annual Reviews",
"publication": "Annual Review of Biomedical Engineering",
"publication_date": "2014-07",
"volume": "16",
"pages": "155-185"
},
{
"id": "authors:5rbhv-ess85",
"collection": "authors",
"collection_id": "5rbhv-ess85",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-131030120",
"type": "article",
"title": "Continuous scanning of a time-reversed ultrasonically encoded optical focus by reflection-mode digital phase conjugation",
"author": [
{
"family_name": "Suzuki",
"given_name": "Yuta",
"clpid": "Suzuki-Yuta"
},
{
"family_name": "Tay",
"given_name": "Jian Wei",
"clpid": "Tay-Jian-Wei"
},
{
"family_name": "Yang",
"given_name": "Qiang",
"clpid": "Yang-Qiang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Time-reversed ultrasonically encoded (TRUE) optical focusing in turbid media was previously implemented using both analog and digital phase conjugation. The digital approach, in addition to its large energy gain, can improve the focal intensity and resolution by iterative focusing. However, performing iterative focusing at each focal position can be time-consuming. Here, we show that by gradually moving the focal position, the TRUE focal intensity is improved, as in iterative focusing at a fixed position, and can be continuously scanned to image fluorescent targets in a shorter time. In addition, our setup is, to the best of our knowledge, the first demonstration of TRUE focusing using a digital phase conjugate mirror in a reflection mode, which is more suitable for practical applications.",
"doi": "10.1364/OL.39.003441",
"pmcid": "PMC4138829",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2014-06-15",
"series_number": "12",
"volume": "39",
"issue": "12",
"pages": "3441-3444"
},
{
"id": "authors:pkg71-ny348",
"collection": "authors",
"collection_id": "pkg71-ny348",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-130137719",
"type": "article",
"title": "Catheter-based photoacoustic endoscope",
"author": [
{
"family_name": "Yang",
"given_name": "Joon-Mo",
"clpid": "Yang-Joon-Mo"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We report a flexible shaft-based mechanical scanning photoacoustic endoscopy (PAE) system that can be potentially used for imaging the human gastrointestinal tract via the instrument channel of a clinical video endoscope. The development of such a catheter endoscope has been an important challenge to realize the technique's benefits in clinical settings. We successfully implemented a prototype PAE system that has a 3.2-mm diameter and 2.5-m long catheter section. As the instrument's flexible shaft and scanning tip are fully encapsulated in a plastic catheter, it easily fits within the 3.7-mm diameter instrument channel of a clinical video endoscope. Here, we demonstrate the intra-instrument channel workability and in vivo animal imaging capability of the PAE system.",
"doi": "10.1117/1.JBO.19.6.066001",
"pmcid": "PMC4041025",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2014-06",
"series_number": "6",
"volume": "19",
"issue": "6",
"pages": "Art. No. 066001"
},
{
"id": "authors:nzpbq-w5t12",
"collection": "authors",
"collection_id": "nzpbq-w5t12",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-085803964",
"type": "article",
"title": "Sensitivity of photoacoustic microscopy",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Building on its high spatial resolution, deep penetration depth and excellent image contrast, 3D photoacoustic microscopy (PAM) has grown tremendously since its first publication in 2005. Integrating optical excitation and acoustic detection, PAM has broken through both the optical diffusion and optical diffraction limits. PAM has 100% relative sensitivity to optical absorption (i.e., a given percentage change in the optical absorption coefficient yields the same percentage change in the photoacoustic amplitude), and its ultimate detection sensitivity is limited only by thermal noise. Focusing on the engineering aspects of PAM, this Review discusses the detection sensitivity of PAM, compares the detection efficiency of different PAM designs, and summarizes the imaging performance of various endogenous and exogenous contrast agents. It then describes representative PAM applications with high detection sensitivity, and outlines paths to further improvement.",
"doi": "10.1016/j.pacs.2014.04.002",
"pmcid": "PMC4182819",
"issn": "2213-5979",
"publisher": "Elsevier",
"publication": "Photoacoustics",
"publication_date": "2014-06",
"series_number": "2",
"volume": "2",
"issue": "2",
"pages": "87-101"
},
{
"id": "authors:gp6xc-ypr05",
"collection": "authors",
"collection_id": "gp6xc-ypr05",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160721-081558591",
"type": "article",
"title": "Radioactive ^(198)Au-Doped Nanostructures with Different Shapes for In Vivo Analyses of Their Biodistribution, Tumor Uptake, and Intratumoral Distribution",
"author": [
{
"family_name": "Black",
"given_name": "Kvar C. L.",
"clpid": "Black-K-C-L"
},
{
"family_name": "Wang",
"given_name": "Yucai",
"clpid": "Wang-Yucai"
},
{
"family_name": "Luehmann",
"given_name": "Hannah P.",
"clpid": "Luehmann-H-P"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Xing",
"given_name": "Wenxin",
"clpid": "Xing-Wenxin"
},
{
"family_name": "Pang",
"given_name": "Bo",
"clpid": "Pang-Bo"
},
{
"family_name": "Zhao",
"given_name": "Yongfeng",
"clpid": "Zhao-Yongfeng"
},
{
"family_name": "Cutler",
"given_name": "Cathy S.",
"clpid": "Cutler-C-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Liu",
"given_name": "Yongjian",
"clpid": "Liu-Yongjian"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "With Au nanocages as an example, we recently demonstrated that radioactive ^(198)Au could be incorporated into the crystal lattice of Au nanostructures for simple and reliable quantification of their in vivo biodistribution by measuring the \u03b3 radiation from ^(198)Au decay and for optical imaging by detecting the Cerenkov radiation. Here we extend the capability of this strategy to synthesize radioactive ^(198)Au nanostructures with a similar size but different shapes and then compare their biodistribution, tumor uptake, and intratumoral distribution using a murine EMT6 breast cancer model. Specifically, we investigated Au nanospheres, nanodisks, nanorods, and cubic nanocages. After PEGylation, an aqueous suspension of the radioactive Au nanostructures was injected into a tumor-bearing mouse intravenously, and their biodistribution was measured from the \u03b3 radiation while their tumor uptake was directly imaged using the Cerenkov radiation. Significantly higher tumor uptake was observed for the Au nanospheres and nanodisks relative to the Au nanorods and nanocages at 24 h postinjection. Furthermore, autoradiographic imaging was performed on thin slices of the tumor after excision to resolve the intratumoral distributions of the nanostructures. While both the Au nanospheres and nanodisks were only observed on the surfaces of the tumors, the Au nanorods and nanocages were distributed throughout the tumors.",
"doi": "10.1021/nn406258m",
"pmcid": "PMC4358630",
"issn": "1936-0851",
"publisher": "American Chemical Society",
"publication": "ACS Nano",
"publication_date": "2014-05-27",
"series_number": "5",
"volume": "8",
"issue": "5",
"pages": "4385-4394"
},
{
"id": "authors:c872r-88298",
"collection": "authors",
"collection_id": "c872r-88298",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-141620234",
"type": "article",
"title": "Fast spatiotemporal image reconstruction based on low-rank matrix estimation for dynamic photoacoustic computed tomography",
"author": [
{
"family_name": "Wang",
"given_name": "Kun",
"clpid": "Wang-Kun"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Li",
"given_name": "Changhui",
"clpid": "Li-Changhui"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
}
],
"abstract": "In order to monitor dynamic physiological events in near-real time, a variety of photoacoustic computed tomography (PACT) systems have been developed that can rapidly acquire data. Previously reported studies of dynamic PACT have employed conventional static methods to reconstruct a temporally ordered sequence of images on a frame-by-frame basis. Frame-by-frame image reconstruction (FBFIR) methods fail to exploit correlations between data frames and are known to be statistically and computationally suboptimal. In this study, a low-rank matrix estimation-based spatiotemporal image reconstruction (LRME-STIR) method is investigated for dynamic PACT applications. The LRME-STIR method is based on the observation that, in many PACT applications, the number of frames is much greater than the rank of the ideal noiseless data matrix. Using both computer-simulated and experimentally measured photoacoustic data, the performance of the LRME-STIR method is compared with that of conventional FBFIR method followed by image-domain filtering. The results demonstrate that the LRME-STIR method is not only computationally more efficient but also produces more accurate dynamic PACT images than a conventional FBFIR method followed by image-domain filtering.",
"doi": "10.1117/1.JBO.19.5.056007",
"pmcid": "PMC4046831",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2014-05-09",
"series_number": "5",
"volume": "19",
"issue": "5",
"pages": "Art. No. 056007"
},
{
"id": "authors:w66py-jcf97",
"collection": "authors",
"collection_id": "w66py-jcf97",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-093321693",
"type": "article",
"title": "Small-Animal Whole-Body Photoacoustic Tomography: A Review",
"author": [
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "With the wide use of small animals for biomedical studies, in vivo small-animal whole-body imaging plays an increasingly important role. Photoacoustic tomography (PAT) is an emerging whole-body imaging modality that shows great potential for preclinical research. As a hybrid technique, PAT is based on the acoustic detection of optical absorption from either endogenous tissue chromophores, such as oxyhemoglobin and deoxyhemoglobin, or exogenous contrast agents. Because ultrasound scatters much less than light in tissue, PAT generates high-resolution images in both the optical ballistic and diffusive regimes. Using near-infrared light, which has relatively low blood absorption, PAT can image through the whole body of small animals with acoustically defined spatial resolution. Anatomical and vascular structures are imaged with endogenous hemoglobin contrast, while functional and molecular images are enabled by the wide choice of exogenous optical contrasts. This paper reviews the rapidly growing field of small-animal whole-body PAT and highlights studies done in the past decade.",
"doi": "10.1109/TBME.2013.2283507",
"pmcid": "PMC3965654",
"issn": "0018-9294",
"publisher": "IEEE",
"publication": "IEEE Transactions on Biomedical Engineering",
"publication_date": "2014-05",
"series_number": "5",
"volume": "61",
"issue": "5",
"pages": "1380-1389"
},
{
"id": "authors:epa1y-pwd58",
"collection": "authors",
"collection_id": "epa1y-pwd58",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190227-104319278",
"type": "article",
"title": "Plasmonics-enhanced and optically modulated delivery of gold nanostars into brain tumor",
"author": [
{
"family_name": "Yuan",
"given_name": "Hsiangkuo",
"clpid": "Yuan-Hsiangkuo"
},
{
"family_name": "Wilson",
"given_name": "Christy M.",
"clpid": "Wilson-C-M"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Doyle",
"given_name": "Sarah L.",
"clpid": "Doyle-S-L"
},
{
"family_name": "Li",
"given_name": "Shuqin",
"clpid": "Li-Shuqin"
},
{
"family_name": "Fales",
"given_name": "Andrew M.",
"clpid": "Fales-A-M"
},
{
"family_name": "Liu",
"given_name": "Yang",
"orcid": "0000-0002-8155-9134",
"clpid": "Liu-Yang"
},
{
"family_name": "Ozaki",
"given_name": "Ema",
"clpid": "Ozaki-E"
},
{
"family_name": "Mulfaul",
"given_name": "Kelly",
"clpid": "Mulfaul-K"
},
{
"family_name": "Hanna",
"given_name": "Gabi",
"clpid": "Hanna-G"
},
{
"family_name": "Palmer",
"given_name": "Gregory M.",
"clpid": "Palmer-G-M"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Grant",
"given_name": "Gerald A.",
"clpid": "Grant-G-A"
},
{
"family_name": "Vo-Dinh",
"given_name": "Tuan",
"clpid": "Vo-Dinh-Tuan"
}
],
"abstract": "Plasmonics-active gold nanostars exhibiting strong imaging contrast and efficient photothermal transduction were synthesized for a novel pulsed laser-modulated plasmonics-enhanced brain tumor microvascular permeabilization. We demonstrate a selective, optically modulated delivery of nanoprobes into the tumor parenchyma with minimal off-target distribution.",
"doi": "10.1039/c3nr06770j",
"pmcid": "PMC4343032",
"issn": "2040-3364",
"publisher": "Royal Society of Chemistry",
"publication": "Nanoscale",
"publication_date": "2014-04-21",
"series_number": "8",
"volume": "6",
"issue": "8",
"pages": "4078-4082"
},
{
"id": "authors:askrs-3m362",
"collection": "authors",
"collection_id": "askrs-3m362",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160621-070215517",
"type": "article",
"title": "Nonlinear light-sheet fluorescence microscopy by photobleaching imprinting",
"author": [
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present a nonlinear light-sheet fluorescence microscopy (LSFM) scheme based on photobleaching imprinting. By measuring photobleaching-induced fluorescence decay, our method simultaneously achieves a large imaging field of view and a thin optical section. Furthermore, the scattered-light-induced background is significantly reduced, considerably improving image contrast. Our method is expected to expand the application field of LSFM into the optical quasi-ballistic regime, enabling studies on non-transparent biological samples.",
"doi": "10.1098/rsif.2013.0851",
"pmcid": "PMC3928927",
"issn": "1742-5689",
"publisher": "The Royal Society",
"publication": "Journal of the Royal Society Interface",
"publication_date": "2014-04-06",
"series_number": "93",
"volume": "11",
"issue": "93",
"pages": "Art. No. 20130851"
},
{
"id": "authors:8x4z1-h0r05",
"collection": "authors",
"collection_id": "8x4z1-h0r05",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-143852261",
"type": "article",
"title": "Fully motorized optical-resolution photoacoustic microscopy",
"author": [
{
"family_name": "Li",
"given_name": "Lei",
"orcid": "0000-0001-6164-2646",
"clpid": "Li-Lei"
},
{
"family_name": "Yeh",
"given_name": "Chenghung",
"clpid": "Yeh-Chenghung"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Soetikno",
"given_name": "Brian T.",
"clpid": "Soetikno-B-T"
},
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have developed fully motorized optical-resolution photoacoustic microscopy (OR-PAM), which integrates five complementary scanning modes and simultaneously provides a high imaging speed and a wide field of view (FOV) with 2.6 \u03bcm lateral resolution. With one-dimensional (1D) motion-mode mechanical scanning, we measured the blood flow through a cross section of a blood vessel in vivo. With two-dimensional (2D) optical scanning at a laser repetition rate of 40 kHz, we achieved a 2 kHz B-scan rate over a range of 50 \u03bcm with 20 A-lines and 50 Hz volumetric-scan rate over a FOV of 50\u2009\u2009\u03bcm\u00d750\u2009\u2009\u03bcm with 400 A-lines, which enabled real-time tracking of cellular dynamics in vivo. With synchronized 1D optical and 2D mechanical hybrid scanning, we imaged a 10\u2009\u2009mm\u00d78\u2009\u2009mm FOV within three minutes, which is 20 times faster than the conventional mechanical scan in our second-generation OR-PAM. With three-dimensional mechanical contour scanning, we maintained the optimal signal-to-noise ratio and spatial resolution of OR-PAM while imaging objects with uneven surfaces, which is essential for quantitative studies.",
"doi": "10.1364/OL.39.002117",
"pmcid": "PMC4048805",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2014-04-01",
"series_number": "7",
"volume": "39",
"issue": "7",
"pages": "2117-2120"
},
{
"id": "authors:9vntt-m7983",
"collection": "authors",
"collection_id": "9vntt-m7983",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160706-145215190",
"type": "article",
"title": "Recent advancement in transcranial brain imaging using photoacoustic computed tomography",
"author": [
{
"family_name": "Anastasio",
"given_name": "Mark",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
},
{
"family_name": "Mitsuhashi",
"given_name": "Kenji",
"clpid": "Mitsuhashi-K"
},
{
"family_name": "Huang",
"given_name": "Chao",
"clpid": "Huang-Chao"
},
{
"family_name": "Schoonover",
"given_name": "Robert",
"clpid": "Schoonover-R"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic computed tomography (PACT) holds great promise for transcranial brain imaging. However, the strong reflection, scattering, and attenuation of acoustic waves by the skull present significant challenges for image reconstruction. In this talk, we will review our recent progress on transcranial PACT image reconstruction. Our contributions include the following: (1) development of a methodology to establish a discrete transcranial PACT image model by use of adjunct X-ray CT data; (2) development of image reconstruction methods that can compensate for speed-of-sound and density variations within the skull; and (3) a detailed investigation of the role of shear waves in transcranial PACT. Computer-simulated and experimental data are employed to demonstrate the feasibility of transcranial PACT.",
"doi": "10.1121/1.4877210",
"issn": "0001-4966",
"publisher": "Acoustical Society of America",
"publication": "Journal of the Acoustical Society of America",
"publication_date": "2014-04",
"series_number": "4",
"volume": "135",
"issue": "4",
"pages": "2208"
},
{
"id": "authors:9t9dg-mwh92",
"collection": "authors",
"collection_id": "9t9dg-mwh92",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-123826742",
"type": "article",
"title": "Calibration-free structured-illumination photoacoustic flowgraphy of transverse flow in scattering media",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Gilson",
"given_name": "Rebecca C.",
"clpid": "Gilson-R-C"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We propose a calibration-free photoacoustic (PA) method for transverse flow measurements. In this method, a pulsed periodically structured (i.e., grating patterned) optical beam is used to illuminate flowing absorptive particles in an optically scattering medium. The PA signal amplitudes measured over consecutive laser pulses carry an imprint of the illumination structure. The modulation frequency of the imprint is proportional to the component of the flow speed projected onto the normal axis of the striped illumination pattern. This method can tolerate high particle density, and is insensitive to the particle size, thus calibration-free. Bovine blood and microsphere phantoms were used to validate the proposed method. Blood flow in a mouse ear was measured in vivo as well.",
"doi": "10.1117/1.JBO.19.4.046007",
"pmcid": "PMC3980702",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2014-04",
"series_number": "4",
"volume": "19",
"issue": "4",
"pages": "Art. No. 046007"
},
{
"id": "authors:hg001-9e110",
"collection": "authors",
"collection_id": "hg001-9e110",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-094155673",
"type": "article",
"title": "Breakthroughs in Photonics 2013: Photoacoustic Tomography in Biomedicine",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) is one of the fastest growing biomedical imaging modalities in the last decade. Building on its high scalability and complementary imaging contrast to other mainstream modalities, PAT has gained substantial momentum in both preclinical and clinical studies. In 2013, PAT has grown markedly in both its technological capabilities and biomedical applications. In particular, breakthroughs have been made in super-resolution imaging, deep blood flow measurement, small animal resting state brain mapping, video rate functional human imaging, and human breast imaging. These breakthroughs have either successfully solved long-standing technical issues in PAT or significantly enhanced its imaging capability. This review will summarize state-of-the-art developments in PAT and highlight a few representative achievements of the year 2013.",
"doi": "10.1109/JPHOT.2014.2310197",
"pmcid": "PMC4224294",
"issn": "1943-0655",
"publisher": "IEEE",
"publication": "IEEE Photonics Journal",
"publication_date": "2014-04",
"series_number": "2",
"volume": "6",
"issue": "2",
"pages": "1-6"
},
{
"id": "authors:kgp3r-x8190",
"collection": "authors",
"collection_id": "kgp3r-x8190",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160726-105443178",
"type": "article",
"title": "Urogenital photoacoustic endoscope",
"author": [
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Yang",
"given_name": "Joon-Mo",
"clpid": "Yang-Joon-Mo"
},
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "Yeh",
"given_name": "Cheng-Hung",
"clpid": "Yeh-Cheng-Hung"
},
{
"family_name": "Zhu",
"given_name": "Liren",
"orcid": "0000-0002-6338-9338",
"clpid": "Zhu-Liren"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic (PA) endoscopy for human urogenital imaging has the potential to diagnose many important diseases, such as endometrial and prostate cancers. We have specifically developed a 12.7 mm diameter, rigid, side-scanning PA endoscopic probe for such applications. The key features of this endoscope are the streamlined structure for smooth cavity introduction and the proximal actuation mechanism for fast scanning. Here we describe the probe's composition and scanning mechanism and present in vivo experimental results suggesting its potential for comprehensive clinical applications.",
"doi": "10.1364/OL.39.001473",
"pmcid": "PMC4009352",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2014-03-15",
"series_number": "6",
"volume": "39",
"issue": "6",
"pages": "1473-1476"
},
{
"id": "authors:s4ewf-v8e98",
"collection": "authors",
"collection_id": "s4ewf-v8e98",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180911-164454823",
"type": "article",
"title": "Calibration-free absolute quantification of particle concentration by statistical analyses of photoacoustic signals in vivo",
"author": [
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Currently, laser fluence calibration is typically required for quantitative measurement of particle concentration in photoacoustic imaging. Here, we present a calibration-free method to quantify the absolute particle concentration by statistically analyzing photoacoustic signals. The proposed method is based on the fact that Brownian motion induces particle count fluctuation in the detection volume. If the count of particles in the detection volume is assumed to follow the Poisson distribution, its expected value can be calculated by the photoacoustic signal mean and variance. We first derived a theoretical model for photoacoustic signals. Then, we applied our method to quantitative measurement of different concentrations of various particles, including red blood cells. Finally, we performed in vivo experiments to demonstrate the potential of our method in biological applications. The experimental results agreed well with the predictions from the theoretical model suggesting that our method can be used for noninvasive measurement of absolute particle concentrations in deep tissue without fluence calibration.",
"doi": "10.1117/1.jbo.19.3.037001",
"pmcid": "PMC3939437",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2014-03",
"series_number": "3",
"volume": "19",
"issue": "3",
"pages": "Art. No. 037001"
},
{
"id": "authors:vjg4z-ba588",
"collection": "authors",
"collection_id": "vjg4z-ba588",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-084900974",
"type": "article",
"title": "Integrated photoacoustic, confocal, and two-photon microscope",
"author": [
{
"family_name": "Rao",
"given_name": "Bin",
"orcid": "0000-0001-6494-3110",
"clpid": "Rao-Bin"
},
{
"family_name": "Soto",
"given_name": "Florentina",
"clpid": "Soto-F"
},
{
"family_name": "Kerschensteiner",
"given_name": "Daniel",
"clpid": "Kerschensteiner-D"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The invention of green fluorescent protein and other molecular fluorescent probes has promoted applications of confocal and two-photon fluorescence microscopy in biology and medicine. However, exogenous fluorescence contrast agents may affect cellular structure and function, and fluorescence microscopy cannot image nonfluorescent chromophores. We overcome this limitation by integrating optical-resolution photoacoustic microscopy into a modern Olympus IX81 confocal, two-photon, fluorescence microscope setup to provide complementary, label-free, optical absorption contrast. Automatically coregistered images can be generated from the same sample. Imaging applications in ophthalmology, developmental biology, and plant science are demonstrated. For the first time, in a familiar microscopic fluorescence imaging setting, this trimodality microscope provides a platform for future biological and medical discoveries.",
"doi": "10.1117/1.JBO.19.3.036002",
"pmcid": "PMC3939434",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2014-03",
"series_number": "3",
"volume": "19",
"issue": "3",
"pages": "Art. No. 036002"
},
{
"id": "authors:gtm6q-hjg14",
"collection": "authors",
"collection_id": "gtm6q-hjg14",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160713-134445918",
"type": "article",
"title": "Dependence of optical scattering from Intralipid in gelatin-gel based tissue-mimicking phantoms on mixing temperature and time",
"author": [
{
"family_name": "Lai",
"given_name": "Puxiang",
"clpid": "Lai-Puxiang"
},
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Intralipid is widely used as an optical scattering agent in tissue-mimicking phantoms. Accurate control when using Intralipid is critical to match the optical diffusivity of phantoms to the prescribed value. Currently, most protocols of Intralipid-based hydrogel phantom fabrication focus on factors such as Intralipid brand and concentration. In this note, for the first time to our knowledge, we explore the dependence of the optical reduced scattering coefficient (at 532 nm optical wavelength) on the temperature and the time of mixing Intralipid with gelatin-water solution. The studied samples contained 1% Intralipid and were measured with oblique-incidence reflectometry. It was found that the reduced scattering coefficient increased when the Intralipid-gelatin-water mixture began to solidify at room temperature. For phantoms that had already solidified completely, the diffusivity was shown to be significantly influenced by the temperature and the duration of the mixing course. The dependence of the measured diffusivity on the mixing conditions was confirmed by experimental observations. Moreover, the mechanism behind the dependence behavior is discussed.",
"doi": "10.1117/1.JBO.19.3.035002",
"pmcid": "PMC3945467",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2014-03",
"series_number": "3",
"volume": "19",
"issue": "3",
"pages": "Art. No. 035002"
},
{
"id": "authors:69se6-6h612",
"collection": "authors",
"collection_id": "69se6-6h612",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160614-092434132",
"type": "article",
"title": "Imaging technology in mice enhances human brain research",
"author": [
{
"family_name": "Avanaki",
"given_name": "Mohammad R. N.",
"clpid": "Avanaki-M-R-N"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Wan",
"given_name": "Hanlin",
"clpid": "Wan-Hanlin"
},
{
"family_name": "Bauer",
"given_name": "Adam Q.",
"clpid": "Bauer-A-Q"
},
{
"family_name": "Culver",
"given_name": "Joseph P.",
"clpid": "Culver-J-P"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography offering a large field of view and high spatial resolution enables, for the first time, noninvasive imaging of resting-state functional connectivity in the murine brain.",
"doi": "10.1117/2.1201402.005349",
"issn": "1818-2259",
"publisher": "SPIE",
"publication": "SPIE Newsroom",
"publication_date": "2014-02-21",
"pages": "Art. No. 5349"
},
{
"id": "authors:53n8c-6a216",
"collection": "authors",
"collection_id": "53n8c-6a216",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-102348611",
"type": "article",
"title": "Multicontrast photoacoustic in vivo imaging using near-infrared fluorescent proteins",
"author": [
{
"family_name": "Krumholz",
"given_name": "Arie",
"clpid": "Krumholz-A"
},
{
"family_name": "Shcherbakova",
"given_name": "Daria M.",
"clpid": "Shcherbakova-D-M"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Verkhusha",
"given_name": "Vladislav V.",
"orcid": "0000-0002-2083-8121",
"clpid": "Verkhusha-V-V"
}
],
"abstract": "Non-invasive imaging of biological processes in vivo is invaluable in advancing biology. Photoacoustic tomography is a scalable imaging technique that provides higher resolution at greater depths in tissue than achievable by purely optical methods. Here we report the application of two spectrally distinct near-infrared fluorescent proteins, iRFP670 and iRFP720, engineered from bacterial phytochromes, as photoacoustic contrast agents. iRFPs provide tissue-specific contrast without the need for delivery of any additional substances. Compared to conventional GFP-like red-shifted fluorescent proteins, iRFP670 and iRFP720 demonstrate stronger photoacoustic signals at longer wavelengths, and can be spectrally resolved from each other and hemoglobin. We simultaneously visualized two differently labeled tumors, one with iRFP670 and the other with iRFP720, as well as blood vessels. We acquired images of a mouse as 2D sections of a whole animal, and as localized 3D volumetric images with high contrast and sub-millimeter resolution at depths up to 8\u2005mm. Our results suggest iRFPs are genetically-encoded probes of choice for simultaneous photoacoustic imaging of several tissues or processes in vivo.",
"doi": "10.1038/srep03939",
"pmcid": "PMC3909896",
"issn": "2045-2322",
"publisher": "Nature Publishing Group",
"publication": "Scientific Reports",
"publication_date": "2014-02-03",
"volume": "4",
"pages": "Art. no. 3939"
},
{
"id": "authors:rwgt0-0jq23",
"collection": "authors",
"collection_id": "rwgt0-0jq23",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160721-133102324",
"type": "article",
"title": "Spatially Fourier-encoded photoacoustic microscopy using a digital micromirror device",
"author": [
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have developed spatially Fourier-encoded photoacoustic (PA) microscopy using a digital micromirror device. The spatial intensity distribution of laser pulses is Fourier-encoded, and a series of such encoded PA measurements allows one to decode the spatial distribution of optical absorption. The throughput and Fellgett advantages were demonstrated by imaging a chromium target. By using 63 spatial elements, the signal-to-noise ratio in the recovered PA signal was enhanced by \u223c4\u00d7. The system was used to image two biological targets, a monolayer of red blood cells and melanoma cells.",
"doi": "10.1364/OL.39.000430",
"pmcid": "PMC3978131",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2014-02-01",
"series_number": "3",
"volume": "39",
"issue": "3",
"pages": "430-433"
},
{
"id": "authors:r6xr6-sy998",
"collection": "authors",
"collection_id": "r6xr6-sy998",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-153145653",
"type": "article",
"title": "Photoacoustic thermography of tissue",
"author": [
{
"family_name": "Ke",
"given_name": "Haixin",
"clpid": "Ke-Haixin"
},
{
"family_name": "Tai",
"given_name": "Stephen",
"clpid": "Tai-Stephen"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic (PA) techniques can measure temperature in biological tissues because PA signal amplitude is sensitive to tissue temperature. So far, temperature-measuring PA techniques have focused on sensing of temperature changes at a single position. In this work, we photoacoustically measured spatial distribution of temperature in deep tissue. By monitoring the temperature at a single position using a thermocouple, the relationship between the PA signal amplitude and the actual temperature was determined. The relationship was then used to translate a PA image into a temperature map. This study showed that it is possible to calibrate the system for the temperature range of hyperthermia using single-point measurements over a smaller temperature range. Our experimental results showed a precision of \u22120.8\u00b10.4\u00b0C (mean\u00b1standard error) in temperature measurement, and a spatial resolution as fine as 1.0 mm. PA techniques can be potentially applied to monitor temperature distribution deep in tissue during hyperthermia treatment of cancer.",
"doi": "10.1117/1.JBO.19.2.026003",
"pmcid": "PMC3922142",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2014-02",
"series_number": "2",
"volume": "19",
"issue": "2",
"pages": "Art. No. 026003"
},
{
"id": "authors:ct74a-h9j93",
"collection": "authors",
"collection_id": "ct74a-h9j93",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160726-103224313",
"type": "article",
"title": "Ultrasonically encoded wavefront shaping for focusing into random media",
"author": [
{
"family_name": "Tay",
"given_name": "Jian Wei",
"clpid": "Tay-Jian-Wei"
},
{
"family_name": "Lai",
"given_name": "Puxiang",
"clpid": "Lai-Puxiang"
},
{
"family_name": "Suzuki",
"given_name": "Yuta",
"clpid": "Suzuki-Yuta"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Phase distortions due to scattering in random media restrict optical focusing beyond one transport mean free path. However, scattering can be compensated for by applying a correction to the illumination wavefront using spatial light modulators. One method of obtaining the wavefront correction is by iterative determination using an optimization algorithm. In the past, obtaining a feedback signal required either direct optical access to the target region, or invasive embedding of molecular probes within the random media. Here, we propose using ultrasonically encoded light as feedback to guide the optimization dynamically and non-invasively. In our proof-of-principle demonstration, diffuse light was refocused to the ultrasound focal zone, with a focus-to-background ratio of more than one order of magnitude after 600 iterations. With further improvements, especially in optimization speed, the proposed method should find broad applications in deep tissue optical imaging and therapy.",
"doi": "10.1038/srep03918",
"pmcid": "PMC3905274",
"issn": "2045-2322",
"publisher": "Nature Publishing Group",
"publication": "Scientific Reports",
"publication_date": "2014-01-29",
"volume": "4",
"pages": "Art. No. 3918"
},
{
"id": "authors:fvtnk-6sa75",
"collection": "authors",
"collection_id": "fvtnk-6sa75",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-095840945",
"type": "article",
"title": "Multi-parametric quantitative microvascular imaging with optical-resolution photoacoustic microscopy in vivo",
"author": [
{
"family_name": "Yang",
"given_name": "Zhenyuan",
"clpid": "Yang-Zhenyuan"
},
{
"family_name": "Chen",
"given_name": "Jianhua",
"clpid": "Chen-Jianhua"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Lin",
"given_name": "Riqiang",
"clpid": "Lin-Riqiang"
},
{
"family_name": "Meng",
"given_name": "Jing",
"orcid": "0000-0002-9069-8988",
"clpid": "Meng-Jing"
},
{
"family_name": "Liu",
"given_name": "Chengbo",
"clpid": "Liu-Chengbo"
},
{
"family_name": "Yang",
"given_name": "Jinhua",
"clpid": "Yang-Jinhua"
},
{
"family_name": "Li",
"given_name": "Xiang",
"clpid": "Li-Xiang"
},
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Song",
"given_name": "Liang",
"clpid": "Song-Liang"
}
],
"abstract": "Many diseases involve either the formation of new blood vessels (e.g., tumor angiogenesis) or the damage of existing ones (e.g., diabetic retinopathy) at the microcirculation level. Optical-resolution photoacoustic microscopy (OR-PAM), capable of imaging microvessels in 3D in vivo down to individual capillaries using endogenous contrast, has the potential to reveal microvascular information critical to the diagnosis and staging of microcirculation-related diseases. In this study, we have developed a dedicated microvascular quantification (MQ) algorithm for OR-PAM to automatically quantify multiple microvascular morphological parameters in parallel, including the vessel diameter distribution, the microvessel density, the vascular tortuosity, and the fractal dimension. The algorithm has been tested on in vivo OR-PAM images of a healthy mouse, demonstrating high accuracy for microvascular segmentation and quantification. The developed MQ algorithm for OR-PAM may greatly facilitate quantitative imaging of tumor angiogenesis and many other microcirculation related diseases in vivo.",
"doi": "10.1364/OE.22.001500",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "2014-01-27",
"series_number": "2",
"volume": "22",
"issue": "2",
"pages": "1500-1511"
},
{
"id": "authors:6a15n-pd491",
"collection": "authors",
"collection_id": "6a15n-pd491",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-090533800",
"type": "article",
"title": "Photobleaching imprinting microscopy: seeing clearer and deeper",
"author": [
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present a generic sub-diffraction-limited imaging method \u2013 photobleaching imprinting microscopy (PIM) \u2013 for biological fluorescence imaging. A lateral resolution of 110\u2005nm was measured, more than a twofold improvement over the optical diffraction limit. Unlike other super-resolution imaging techniques, PIM does not require complicated illumination modules or specific fluorescent dyes. PIM is expected to facilitate the conversion of super-resolution imaging into a routine lab tool, making it accessible to a much broader biological research community. Moreover, we show that PIM can increase the image contrast of biological tissue, effectively extending the fundamental depth limit of multi-photon fluorescence microscopy.",
"doi": "10.1242/jcs.142943",
"pmcid": "PMC3889396",
"issn": "0021-9533",
"publisher": "Company of Biologists",
"publication": "Journal of Cell Science",
"publication_date": "2014-01-15",
"series_number": "2",
"volume": "127",
"issue": "2",
"pages": "288-294"
},
{
"id": "authors:ewr5j-aa502",
"collection": "authors",
"collection_id": "ewr5j-aa502",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160630-104756677",
"type": "article",
"title": "Fabrication of cell patches using biodegradable scaffolds with a hexagonal array of interconnected pores (SHAIPs)",
"author": [
{
"family_name": "Zhang",
"given_name": "Yu Shrike",
"clpid": "Zhang-Yu-Shrike"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "Cell patches are widely used for healing injuries on the surfaces or interfaces of tissues such as those of epidermis and myocardium. Here we report a novel type of porous scaffolds made of poly(d,l-lactic-co-glycolic acid) for fabricating cell patches. The scaffolds have a single layer of spherical pores arranged in a unique hexagonal pattern and are therefore referred to as \"scaffolds with a hexagonal array of interconnected pores (SHAIPs)\". SHAIPs contain both uniform pores and interconnecting windows that can facilitate the exchange of biomacromolecules, ensure homogeneous cell seeding, and promote cell migration. As a proof-of-concept demonstration, we have created skeletal muscle patches with a thickness of approximately 150 \u03bcm using SHAIPs. The myoblasts seeded in the scaffolds maintained high viability and were able to differentiate into multi-nucleated myotubes. Moreover, neovasculature could efficiently develop into the patches upon subcutaneous implantation in vivo.",
"doi": "10.1016/j.polymer.2013.06.019",
"pmcid": "PMC3891771",
"issn": "0032-3861",
"publisher": "Elsevier",
"publication": "Polymer",
"publication_date": "2014-01-14",
"series_number": "1",
"volume": "55",
"issue": "1",
"pages": "445-452"
},
{
"id": "authors:dwddf-gqb75",
"collection": "authors",
"collection_id": "dwddf-gqb75",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160616-081038340",
"type": "article",
"title": "Photoimprint Photoacoustic Microscopy for Three-Dimensional Label-Free Subdiffraction Imaging",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Subdiffraction optical microscopy allows the imaging of cellular and subcellular structures with a resolution finer than the diffraction limit. Here, combining the absorption-based photoacoustic effect and intensity-dependent photobleaching effect, we demonstrate a simple method for subdiffraction photoacoustic imaging of both fluorescent and nonfluorescent samples. Our method is based on a double-excitation process, where the first excitation pulse partially and inhomogeneously bleaches the molecules in the diffraction-limited excitation volume, thus biasing the signal contributions from a second excitation pulse striking the same region. The differential signal between the two excitations preserves the signal contribution mostly from the center of the excitation volume, and dramatically sharpens the lateral resolution. Moreover, due to the nonlinear nature of the signal, our method offers an inherent optical sectioning capability, which is lacking in conventional photoacoustic microscopy. By scanning the excitation beam, we performed three-dimensional subdiffraction imaging of varied fluorescent and nonfluorescent species. As any molecules have absorption, this technique has the potential to enable label-free subdiffraction imaging, and can be transferred to other optical imaging modalities or combined with other subdiffraction methods.",
"doi": "10.1103/PhysRevLett.112.014302",
"pmcid": "PMC3957272",
"issn": "0031-9007",
"publisher": "American Physical Society",
"publication": "Physical Review Letters",
"publication_date": "2014-01-10",
"series_number": "1",
"volume": "112",
"issue": "1",
"pages": "Art. No. 014302"
},
{
"id": "authors:6efc1-3pv39",
"collection": "authors",
"collection_id": "6efc1-3pv39",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-100035660",
"type": "article",
"title": "High-resolution photoacoustic tomography of resting-state functional connectivity in the mouse brain",
"author": [
{
"family_name": "Nasiriavanaki",
"given_name": "Mohammadreza",
"clpid": "Nasiriavanaki-M"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Wan",
"given_name": "Hanlin",
"clpid": "Wan-Hanlin"
},
{
"family_name": "Bauer",
"given_name": "Adam Quentin",
"clpid": "Bauer-A-Q"
},
{
"family_name": "Culver",
"given_name": "Joseph P.",
"clpid": "Culver-J-P"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The increasing use of mouse models for human brain disease studies presents an emerging need for a new functional imaging modality. Using optical excitation and acoustic detection, we developed a functional connectivity photoacoustic tomography system, which allows noninvasive imaging of resting-state functional connectivity in the mouse brain, with a large field of view and a high spatial resolution. Bilateral correlations were observed in eight functional regions, including the olfactory bulb, limbic, parietal, somatosensory, retrosplenial, visual, motor, and temporal regions, as well as in several subregions. The borders and locations of these regions agreed well with the Paxinos mouse brain atlas. By subjecting the mouse to alternating hyperoxic and hypoxic conditions, strong and weak functional connectivities were observed, respectively. In addition to connectivity images, vascular images were simultaneously acquired. These studies show that functional connectivity photoacoustic tomography is a promising, noninvasive technique for functional imaging of the mouse brain.",
"doi": "10.1073/pnas.1311868111",
"pmcid": "PMC3890828",
"issn": "0027-8424",
"publisher": "National Academy of Sciences",
"publication": "Proceedings of the National Academy of Sciences of the United States of America",
"publication_date": "2014-01-07",
"series_number": "1",
"volume": "111",
"issue": "1",
"pages": "21-26"
},
{
"id": "authors:k4n5f-ty776",
"collection": "authors",
"collection_id": "k4n5f-ty776",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-123855323",
"type": "article",
"title": "Non-Invasive and In Situ Characterization of the Degradation of Biomaterial Scaffolds by Volumetric Photoacoustic Microscopy",
"author": [
{
"family_name": "Zhang",
"given_name": "Yu Shrike",
"clpid": "Zhang-Yu-Shrike"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Xing",
"given_name": "Wenxin",
"clpid": "Xing-Wenxin"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "Degradation is among the most important properties of biomaterial scaffolds, which are indispensable for regenerative medicine. The currently used method relies on the measurement of mass loss across different samples and cannot track the degradation of an individual scaffold in\u2005situ. Here we report, for the first time, the use of multiscale photoacoustic microscopy to non-invasively monitor the degradation of an individual scaffold. We could observe alterations to the morphology and structure of a scaffold at high spatial resolution and deep penetration, and more significantly, quantify the degradation of an individual scaffold as a function of time, both in\u2005vitro and in\u2005vivo. In addition, the remodeling of vasculature inside a scaffold can be visualized simultaneously using a dual-wavelength scanning mode in a label-free manner. This optoacoustic method can be used to monitor the degradation of individual scaffolds, offering a new approach to non-invasively analyze and quantify biomaterial\u2013tissue interactions in conjunction with the assessment of in\u2005vivo vascular parameters.",
"doi": "10.1002/anie.201306282",
"pmcid": "PMC3894115",
"issn": "1433-7851",
"publisher": "Wiley",
"publication": "Angewandte Chemie International Edition",
"publication_date": "2014-01-03",
"series_number": "1",
"volume": "53",
"issue": "1",
"pages": "184-188"
},
{
"id": "authors:11p30-3wm77",
"collection": "authors",
"collection_id": "11p30-3wm77",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-085849120",
"type": "article",
"title": "Label-free photoacoustic microscopy of peripheral nerves",
"author": [
{
"family_name": "Matthews",
"given_name": "Thomas Paul",
"clpid": "Matthews-T-P"
},
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Yao",
"given_name": "Da-Kang",
"clpid": "Yao-Da-Kang"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Peripheral neuropathy is a common neurological problem that affects millions of people worldwide. Diagnosis and treatment of this condition are often hindered by the difficulties in making objective, noninvasive measurements of nerve fibers. Photoacoustic microscopy (PAM) has the ability to obtain high resolution, specific images of peripheral nerves without exogenous contrast. We demonstrated the first proof-of-concept imaging of peripheral nerves using PAM. As validated by both standard histology and photoacoustic spectroscopy, the origin of photoacoustic signals is myelin, the primary source of lipids in the nerves. An extracted sciatic nerve sandwiched between two layers of chicken tissue was imaged by PAM to mimic the in vivo case. Ordered fibrous structures inside the nerve, caused by the bundles of myelin-coated axons, could be observed clearly. With further technical improvements, PAM can potentially be applied to monitor and diagnose peripheral neuropathies.",
"doi": "10.1117/1.JBO.19.1.016004",
"pmcid": "PMC3881606",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2014-01",
"series_number": "1",
"volume": "19",
"issue": "1",
"pages": "Art. no. 016004"
},
{
"id": "authors:r0fkx-9t384",
"collection": "authors",
"collection_id": "r0fkx-9t384",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-152107783",
"type": "article",
"title": "Photoacoustic measurement of the Gr\u00fcneisen parameter of tissue",
"author": [
{
"family_name": "Yao",
"given_name": "Da-Kang",
"clpid": "Yao-Da-Kang"
},
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The Gr\u00fcneisen parameter, a constitutive parameter in photoacoustics, is usually measured from isobaric thermal expansion, which may not be valid for a biological medium due to its heterogeneity. Here, we directly measured the Gr\u00fcneisen parameter by applying photoacoustic spectroscopy. Laser pulses at wavelengths between 460 and 1800 nm were delivered to tissue samples, and photoacoustic signals were detected by flat water-immersion ultrasonic transducers. Least-squares fitting photoacoustic spectra to molar optical absorption spectra showed that the Gr\u00fcneisen parameter was 0.81\u00b10.05 (mean\u00b1SD) for porcine subcutaneous fat tissue and 0.69\u00b10.02 for porcine lipid at room temperature (22\u00b0C). The Gr\u00fcneisen parameter of a red blood cell suspension was linearly related to hemoglobin concentration, and the parameter of bovine serum was 9% greater than that of water at room temperature.",
"doi": "10.1117/1.JBO.19.1.017007",
"pmcid": "PMC3904038",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2014-01",
"series_number": "1",
"volume": "19",
"issue": "1",
"pages": "Art. No. 017007"
},
{
"id": "authors:h0msr-zwr51",
"collection": "authors",
"collection_id": "h0msr-zwr51",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160721-095056076",
"type": "article",
"title": "Retrospective respiration-gated whole-body photoacoustic computed tomography of mice",
"author": [
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Chen",
"given_name": "Wanyi",
"clpid": "Chen-Wanyi"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) is an emerging technique that has a great potential for preclinical whole-body imaging. To date, most whole-body PAT systems require multiple laser shots to generate one cross-sectional image, yielding a frame rate of <1\u2009Hz. Because a mouse breathes at up to 3 Hz, without proper gating mechanisms, acquired images are susceptible to motion artifacts. Here, we introduce, for the first time to our knowledge, retrospective respiratory gating for whole-body photoacoustic computed tomography. This new method involves simultaneous capturing of the animal's respiratory waveform during photoacoustic data acquisition. The recorded photoacoustic signals are sorted and clustered according to the respiratory phase, and an image of the animal at each respiratory phase is reconstructed subsequently from the corresponding cluster. The new method was tested in a ring-shaped confocal photoacoustic computed tomography system with a hardware-limited frame rate of 0.625 Hz. After respiratory gating, we observed sharper vascular and anatomical images at different positions of the animal body. The entire breathing cycle can also be visualized at 20\u2009frames/cycle.",
"doi": "10.1117/1.JBO.19.1.016003",
"pmcid": "PMC3881607",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2014-01",
"series_number": "1",
"volume": "19",
"issue": "1",
"pages": "Art. No. 016003"
},
{
"id": "authors:z4j2j-0q822",
"collection": "authors",
"collection_id": "z4j2j-0q822",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-083628913",
"type": "article",
"title": "Photoacoustic Tomography: Principles and Advances",
"author": [
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) is an emerging imaging modality that shows great potential for preclinical research and clinical practice. As a hybrid technique, PAT is based on the acoustic detection of optical absorption from either endogenous chromophores, such as oxy-hemoglobin and deoxy-hemoglobin, or exogenous contrast agents, such as organic dyes and nanoparticles. Because ultrasound scatters much less than light in tissue, PAT generates high-resolution images in both the optical ballistic and diffusive regimes. Over the past decade, the photoacoustic technique has been evolving rapidly, leading to a variety of exciting discoveries and applications. This review covers the basic principles of PAT and its different implementations. Strengths of PAT are highlighted, along with the most recent imaging results.",
"doi": "10.2528/PIER14032303",
"pmcid": "PMC4311576",
"issn": "1559-8985",
"publisher": "EMW Publishing",
"publication": "Progress In Electromagnetics Research",
"publication_date": "2014",
"volume": "147",
"pages": "1-22"
},
{
"id": "authors:m23rk-5v195",
"collection": "authors",
"collection_id": "m23rk-5v195",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170314-123442385",
"type": "article",
"title": "Photo acoustic tomography",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT), sometimes referred to as optoacoustic tomography, is defined as cross-sectional or three-dimensional (3D) imaging of a material based on the photoacoustic effect (Wang 2009). Therefore, PAT possesses spatial resolution along the depth dimension and at least one of the other two dimensions. In PAT, light is absorbed by biological tissue and converted to transient heating, which is subsequently converted into an ultrasonic wave due to thermoelastic expansion. Detection of the ultrasonic wave yields a tomographic image. Combining rich optical contrast and scalable ultrasonic resolution, PAT is the only imaging modality capable of providing multiscale high-resolution structural, functional, and molecular imaging of organelles, cells, tissues, and organs in vivo. While functional imaging measures physiological parameters, such as oxygenation and blood flow, molecular imaging senses biomarkers to identify specific cancer cells or detects gene expression products to track gene activations.",
"doi": "10.4249/scholarpedia.10278",
"issn": "1941-6016",
"publisher": "Scholarpedia Corporation",
"publication": "Scholarpedia",
"publication_date": "2014",
"series_number": "2",
"volume": "9",
"issue": "2",
"pages": "Art. No. 10278"
},
{
"id": "authors:brf2f-yfv37",
"collection": "authors",
"collection_id": "brf2f-yfv37",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160726-120523415",
"type": "article",
"title": "Absolute photoacoustic thermometry in deep tissue",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Ke",
"given_name": "Haixin",
"clpid": "Ke-Haixin"
},
{
"family_name": "Tai",
"given_name": "Stephen",
"clpid": "Tai-Stephen"
},
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic thermography is a promising tool for temperature measurement in deep tissue. Here we propose an absolute temperature measurement method based on the dual temperature dependences of the Gr\u00fcneisen parameter and the speed of sound in tissue. By taking ratiometric measurements at two adjacent temperatures, we can eliminate the factors that are temperature irrelevant but difficult to correct for in deep tissue. To validate our method, absolute temperatures of blood-filled tubes embedded \u223c9\u2009\u2009mm deep in chicken tissue were measured in a biologically relevant range from 28\u00b0C to 46\u00b0C. The temperature measurement accuracy was \u223c0.6\u00b0C. The results suggest that our method can be potentially used for absolute temperature monitoring in deep tissue during thermotherapy.",
"doi": "10.1364/OL.38.005228",
"pmcid": "PMC3901074",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2013-12-15",
"series_number": "24",
"volume": "38",
"issue": "24",
"pages": "5228-5231"
},
{
"id": "authors:enf50-ngh88",
"collection": "authors",
"collection_id": "enf50-ngh88",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160809-083552600",
"type": "article",
"title": "Wide-field two-dimensional multifocal optical-resolution photoacoustic-computed microscopy",
"author": [
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Li",
"given_name": "Guo",
"clpid": "Li-Guo"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Nasiriavanaki",
"given_name": "Mohammadreza",
"clpid": "Nasiriavanaki-M"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Engelbach",
"given_name": "John A.",
"clpid": "Engelbach-J-A"
},
{
"family_name": "Garbow",
"given_name": "Joel R.",
"clpid": "Garbow-J-R"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging technique that directly images optical absorption in tissue at high spatial resolution. To date, the majority of OR-PAM systems are based on single-focused optical excitation and ultrasonic detection, limiting the wide-field imaging speed. While 1D multifocal OR-PAM (1D-MFOR-PAM) has been developed, the potential of microlens and transducer arrays has not been fully realized. Here we present the development of 2D multifocal optical-resolution photoacoustic-computed microscopy (2D-MFOR-PACM), using a 2D microlens array and a full-ring ultrasonic transducer array. The 10\u2009mm\u00d710\u2009mm microlens array generates 1800 optical foci within the focal plane of the 512-element transducer array, and raster scanning the microlens array yields optical-resolution photoacoustic images. The system has improved the in-plane resolution of a full-ring transducer array from \u2265100 to 29 \u03bcm and achieved an imaging time of 36 s over a 10\u2009\u2009mm\u00d710\u2009\u2009mm field of view. In comparison, the 1D-MFOR-PAM would take more than 4 min to image over the same field of view. The imaging capability of the system was demonstrated on phantoms and animals both ex vivo and in vivo.",
"doi": "10.1364/OL.38.005236",
"pmcid": "PMC3928040",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2013-12-15",
"series_number": "24",
"volume": "38",
"issue": "24",
"pages": "5236-5239"
},
{
"id": "authors:a308f-pt072",
"collection": "authors",
"collection_id": "a308f-pt072",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190227-110952823",
"type": "article",
"title": "Graphene-based contrast agents for photoacoustic and thermoacoustic tomography",
"author": [
{
"family_name": "Lalwani",
"given_name": "Gaurav",
"clpid": "Lalwani-G"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Nie",
"given_name": "Liming",
"clpid": "Nie-Liming"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Sitharaman",
"given_name": "Balaji",
"clpid": "Sitharaman-B"
}
],
"abstract": "In this work, graphene nanoribbons and nanoplatelets were investigated as contrast agents for photoacoustic and thermoacoustic tomography (PAT and TAT). We show that oxidized single- and multi-walled graphene oxide nanoribbons (O-SWGNRs, O-MWGNRs) exhibit approximately 5\u201310 fold signal enhancement for PAT in comparison to blood at the wavelength of 755 nm, and approximately 10\u201328% signal enhancement for TAT in comparison to deionized (DI) water at 3 GHz. Oxidized graphite microparticles (O-GMPs) and exfoliated graphene oxide nanoplatelets (O-GNPs) show no significant signal enhancement for PAT, and approximately 12\u201329% signal enhancement for TAT. These results indicate that O-GNRs show promise as multi-modal PAT and TAT contrast agents, and that O-GNPs are suitable contrast agents for TAT.",
"doi": "10.1016/j.pacs.2013.10.001",
"pmcid": "PMC3904379",
"issn": "2213-5979",
"publisher": "Elsevier",
"publication": "Photoacoustics",
"publication_date": "2013-12",
"series_number": "3-4",
"volume": "1",
"issue": "3-4",
"pages": "62-67"
},
{
"id": "authors:7d0vt-d3w04",
"collection": "authors",
"collection_id": "7d0vt-d3w04",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160616-083706465",
"type": "article",
"title": "Ultrasonically Encoded Photoacoustic Flowgraphy in Biological Tissue",
"author": [
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Blood flow speed is an important functional parameter. Doppler ultrasound flowmetry lacks sufficient sensitivity to slow blood flow (several to tens of millimeters per second) in deep tissue. To address this challenge, we developed ultrasonically encoded photoacoustic flowgraphy combining ultrasonic thermal tagging with photoacoustic imaging. Focused ultrasound generates a confined heat source in acoustically absorptive fluid. Thermal waves propagate with the flow and are directly visualized in pseudo color using photoacoustic computed tomography. The Doppler shift is employed to calculate the flow speed. This method requires only acoustic and optical absorption, and thus is applicable to continuous fluid. A blood flow speed as low as 0.24\u2009\u2009mm\u22c5s^(\u22121) was successfully measured. Deep blood flow imaging was experimentally demonstrated under 5-mm-thick chicken breast tissue.",
"doi": "10.1103/PhysRevLett.111.204301",
"pmcid": "PMC3895050",
"issn": "0031-9007",
"publisher": "American Physical Society",
"publication": "Physical Review Letters",
"publication_date": "2013-11-15",
"series_number": "20",
"volume": "111",
"issue": "20",
"pages": "Art. No. 204301"
},
{
"id": "authors:rseh6-rqg36",
"collection": "authors",
"collection_id": "rseh6-rqg36",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-100550291",
"type": "article",
"title": "Deep subwavelength optical imaging using correlated nano-torches",
"author": [
{
"family_name": "Shen",
"given_name": "Yuecheng",
"orcid": "0000-0003-1990-8142",
"clpid": "Shen-Yuecheng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Shen",
"given_name": "Jung-Tsung",
"clpid": "Shen-Jung-Tsung"
}
],
"abstract": "The authors propose and numerically demonstrate an ultra-high resolution (wavelength/50\u223c40 nm at wavelength \u03bb=2.08\u2009\u03bcm, high-throughput (\u223c66%), and non-destructive optical lens with a large contrast-to-noise ratio, based on the notion of correlated nano-torches formed in a subwavelength metallic grating. The correlations between the torches also allow the determination of the complex refractive index of the sample.",
"doi": "10.1063/1.4832070",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2013-11-11",
"series_number": "20",
"volume": "103",
"issue": "20",
"pages": "Art. No. 201119"
},
{
"id": "authors:30jeh-zmz47",
"collection": "authors",
"collection_id": "30jeh-zmz47",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160805-155627468",
"type": "article",
"title": "Ultrasound-heated photoacoustic flowmetry",
"author": [
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Xing",
"given_name": "Wenxin",
"clpid": "Xing-Wenxin"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We report the development of photoacoustic flowmetry assisted by high-intensity focused ultrasound (HIFU). This novel method employs HIFU to generate a heating impulse in the flow medium, followed by photoacoustic monitoring of the thermal decay process. Photoacoustic flowmetry in a continuous medium remains a challenge in the optical diffusive regime. Here, both the HIFU heating and photoacoustic detection can focus at depths beyond the optical diffusion limit (~1\u2009mm in soft tissue). This method can be applied to a continuous medium, i.e., a medium without discrete scatterers or absorbers resolvable by photoacoustic imaging. Flow speeds up to 41\u2009\u2009mm\u22c5s^(-1) have been experimentally measured in a blood phantom covered by 1.5-mm-thick tissue.",
"doi": "10.1117/1.JBO.18.11.117003",
"pmcid": "PMC4030689",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2013-11",
"series_number": "11",
"volume": "18",
"issue": "11",
"pages": "Art. No. 117003"
},
{
"id": "authors:wdyhv-0cb76",
"collection": "authors",
"collection_id": "wdyhv-0cb76",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160620-160805639",
"type": "article",
"title": "A brief account of nanoparticle contrast agents for photoacoustic imaging",
"author": [
{
"family_name": "Pan",
"given_name": "Dipanjan",
"clpid": "Pan-Dipanjan"
},
{
"family_name": "Kim",
"given_name": "Benjamin",
"clpid": "Kim-Benjamin"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Lanza",
"given_name": "Gregory M.",
"clpid": "Lanza-G-M"
}
],
"abstract": "Photoacoustic imaging (PAI) is a hybrid, nonionizing modality offering excellent spatial resolution, deep penetration, and high soft tissue contrast. In PAI, signal is generated based on the absorption of laser-generated optical energy by endogenous tissues or exogenous contrast agents leading to acoustic emissions detected by an ultrasound transducer. Research in this area over the years has shown that PAI has the ability to provide both physiological and molecular imaging, which can be viewed alone or used in a hybrid modality fashion to extend the anatomic and hemodynamic sensitivities of clinical ultrasound. PAI may be performed using inherent contrast afforded by light absorbing molecules such as hemoglobin, myoglobin, and melanin or exogenous small molecule contrast agent such as near infrared dyes and porphyrins. However, this review summarizes the potential of exogenous nanoparticle-based agents for PAI applications including contrast based on gold particles, carbon nanotubes, and encapsulated copper compounds.",
"doi": "10.1002/wnan.1231",
"pmcid": "PMC4067981",
"issn": "1939-5116",
"publisher": "Wiley",
"publication": "Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology",
"publication_date": "2013-11",
"series_number": "6",
"volume": "5",
"issue": "6",
"pages": "517-543"
},
{
"id": "authors:w2vp8-dfb62",
"collection": "authors",
"collection_id": "w2vp8-dfb62",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160803-103250690",
"type": "article",
"title": "Improving limited-view photoacoustic tomography with an acoustic reflector",
"author": [
{
"family_name": "Huang",
"given_name": "Bin",
"clpid": "Huang-Bin"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The versatility and real-time imaging capability of commercial linear array transducers make them widely used in clinical ultrasound and photoacoustic imaging. However, they often suffer from limited detection view. For instance, acoustic waves traveling at a grazing angle to the transducer surface are difficult to detect. In this letter, we propose a simple and easy approach to ameliorate this problem by using a 45-deg acoustic reflector. The reflector forms a virtual array that is perpendicular to the physical array, thereby doubling the detection coverage. The improvement in image quality in photoacoustic tomography was demonstrated through a hair phantom, a leaf skeleton phantom, and an ex vivo mouse ear experiment.",
"doi": "10.1117/1.JBO.18.11.110505",
"pmcid": "PMC3842504",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2013-11",
"series_number": "11",
"volume": "18",
"issue": "11",
"pages": "Art. No. 110505"
},
{
"id": "authors:a7r9z-jrx61",
"collection": "authors",
"collection_id": "a7r9z-jrx61",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180905-104941380",
"type": "article",
"title": "Time-reversed ultrasonically encoded optical focusing using two ultrasonic transducers for improved ultrasonic axial resolution",
"author": [
{
"family_name": "Yang",
"given_name": "Qiang",
"clpid": "Yang-Qiang"
},
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Lai",
"given_name": "Puxiang",
"clpid": "Lai-Puxiang"
},
{
"family_name": "Xu",
"given_name": "Daxiong",
"clpid": "Xu-Daxiong"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Focusing light inside highly scattering media is a challenging task in biomedical optical imaging, manipulation, and therapy. A recent invention has overcome this challenge by time reversing ultrasonically encoded diffuse light to an ultrasound-modulated volume inside a turbid medium. In this technique, a photorefractive (PR) crystal or polymer can be used as the phase conjugate mirror for optical time reversal. Accordingly, a relatively long ultrasound burst, whose duration matches the PR response time of the PR material, is usually used to encode the diffuse light. This long burst results in poor focusing resolution along the acoustic axis. In this work, we propose to use two intersecting ultrasound beams, emitted from two ultrasonic transducers at different frequencies, to modulate the diffuse light at the beat frequency within the intersection volume. We show that the time reversal of the light encoded at the beat frequency can converge back to the intersection volume. Experimentally, an acoustic axial resolution of \u223c1.1\u2009\u2009mm was demonstrated inside turbid media, agreeing with theoretical estimation.",
"doi": "10.1117/1.JBO.18.11.110502",
"pmcid": "PMC3818018",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2013-11",
"series_number": "11",
"volume": "18",
"issue": "11",
"pages": "Art. No. 110502"
},
{
"id": "authors:97zmd-bwb92",
"collection": "authors",
"collection_id": "97zmd-bwb92",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160630-104116130",
"type": "article",
"title": "Optical sectioning by wide-field photobleaching imprinting microscopy",
"author": [
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present a generic wide-field optical sectioning scheme, photobleaching imprinting microscopy (PIM), for depth-resolved cross-sectional fluorescence imaging. Wide-field PIM works by extracting a nonlinear component that depends on the excitation fluence as a result of photobleaching-induced fluorescence decay. Since no specific fluorescent dyes or illumination modules are required, wide-field PIM is easy to implement on a standard microscope. Moreover, wide-field PIM is superior to deconvolution microscopy in removing background fluorescence, yielding a six-fold improvement in image contrast.",
"doi": "10.1063/1.4827535",
"pmcid": "PMC3829865",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2013-10-28",
"series_number": "18",
"volume": "103",
"issue": "18",
"pages": "Art. No. 183703"
},
{
"id": "authors:v27bx-mfp74",
"collection": "authors",
"collection_id": "v27bx-mfp74",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-104756083",
"type": "article",
"title": "The Challenge of Connecting the Dots in the B.R.A.I.N.",
"author": [
{
"family_name": "Devor",
"given_name": "Anna",
"clpid": "Devor-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative has focused scientific attention on the necessary tools to understand the human brain and mind. Here, we outline our collective vision for what we can achieve within a decade with properly targeted efforts and discuss likely technological deliverables and neuroscience progress.",
"doi": "10.1016/j.neuron.2013.09.008",
"pmcid": "PMC3864648",
"issn": "0896-6273",
"publisher": "Elsevier",
"publication": "Neuron",
"publication_date": "2013-10-16",
"series_number": "2",
"volume": "80",
"issue": "2",
"pages": "270-274"
},
{
"id": "authors:9fcm4-k8h82",
"collection": "authors",
"collection_id": "9fcm4-k8h82",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160726-123500232",
"type": "article",
"title": "Calibration-free in vivo transverse blood flowmetry based on cross correlation of slow time profiles from photoacoustic microscopy",
"author": [
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We propose a cross-correlation-based method to measure blood-flow velocity by using photoacoustic microscopy. Unlike in previous autocorrelation-based methods, the measured flow velocity here is independent of particle size. Thus an absolute flow velocity can be obtained without calibration. We first measured the flow velocity ex vivo, using defibrinated bovine blood. Then flow velocities in vessels with different structures in a mouse ear were quantified in vivo. We further measured the flow variation in the same vessel and at a vessel bifurcation. All the experimental results indicate that our method can be used to accurately quantify blood velocity in vivo.",
"doi": "10.1364/OL.38.003882",
"pmcid": "PMC3831365",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2013-10-01",
"series_number": "19",
"volume": "38",
"issue": "19",
"pages": "3882-3885"
},
{
"id": "authors:p9655-1z406",
"collection": "authors",
"collection_id": "p9655-1z406",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160805-132329639",
"type": "article",
"title": "Photoacoustic recovery after photothermal bleaching in living cells",
"author": [
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present an innovative method, photoacoustic recovery after photothermal bleaching (PRAP), for studying particle dynamics at micron scale via photoacoustic imaging. As an intuitive way to visualize and quantify dynamic processes, PRAP is demonstrated first in a simple phantom study and then in a more complex measurement involving live cells. Compared with the conventional fluorescence-based approach, PRAP provides high signal-to-noise ratio (SNR) imaging with minimal bleaching-induced artifacts during the recovery stage, ideal for monitoring the diffusive and kinetic processes inside a cell.",
"doi": "10.1117/1.JBO.18.10.106004",
"pmcid": "PMC3788654",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2013-10",
"series_number": "10",
"volume": "18",
"issue": "10",
"pages": "Art. No. 106004"
},
{
"id": "authors:sg10j-gwf36",
"collection": "authors",
"collection_id": "sg10j-gwf36",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160727-092516000",
"type": "article",
"title": "Deep-tissue photoacoustic tomography of F\u00f6rster resonance energy transfer",
"author": [
{
"family_name": "Wang",
"given_name": "Yu",
"orcid": "0000-0003-3589-9274",
"clpid": "Wang-Yu"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "F\u00f6rster resonance energy transfer (FRET) is a distance-dependent process that transfers excited state energy from a donor molecule to an acceptor molecule without the emission of a photon. The FRET rate is determined by the proximity between the donor and the acceptor molecules; it becomes significant only when the proximity is within several nanometers. Therefore, FRET has been applied to visualize interactions and conformational changes of biomolecules, such as proteins, lipids, and nucleic acids that cannot be resolved by optical microscopy. Here, we report photoacoustic tomography of FRET efficiency at a 1-cm depth in chicken breast tissue, whereas conventional high-resolution fluorescence imaging is limited to < 0.1\u2009\u2009cm. Photoacoustic tomography is expected to facilitate the examination of FRET phenomena in living organisms.",
"doi": "10.1117/1.JBO.18.10.101316",
"pmcid": "PMC3719951",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2013-10",
"series_number": "10",
"volume": "18",
"issue": "10",
"pages": "Art. No. 101316"
},
{
"id": "authors:ds53j-y9d27",
"collection": "authors",
"collection_id": "ds53j-y9d27",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160803-144514396",
"type": "article",
"title": "Noise-equivalent sensitivity of photoacoustics",
"author": [
{
"family_name": "Winkler",
"given_name": "Amy M.",
"clpid": "Winkler-A-M"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The fundamental limitations of photoacoustic microscopy for detecting optically absorbing molecules are investigated both theoretically and experimentally. We experimentally demonstrate noise-equivalent detection sensitivities of 160,000 methylene blue molecules (270 zeptomol or 2.7\u00d710^(\u221219) mol) and 86,000 oxygenated hemoglobin molecules (140 zeptomol) using narrowband continuous-wave photoacoustics. The ultimate sensitivity of photoacoustics is fundamentally limited by thermal noise, which can present in the acoustic detection system as well as in the medium itself. Under the optimized conditions described herein and using commercially available detectors, photoacoustic microscopy can detect as few as 100s of oxygenated hemoglobin molecules. Realizable improvements to the detector may enable single molecule detection of select molecules.",
"doi": "10.1117/1.JBO.18.9.097003",
"pmcid": "PMC3769636",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2013-09",
"series_number": "9",
"volume": "18",
"issue": "9",
"pages": "Art. No. 097003"
},
{
"id": "authors:vpweb-q8k08",
"collection": "authors",
"collection_id": "vpweb-q8k08",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-105427896",
"type": "article",
"title": "Cross-correlation-based transverse flow measurements using optical resolution photoacoustic microscopy with a digital micromirror device",
"author": [
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A cross-correlation-based method is proposed to quantitatively measure transverse flow velocity using optical resolution photoacoustic (PA) microscopy enhanced with a digital micromirror device (DMD). The DMD is used to alternately deliver two spatially separated laser beams to the target. Through cross-correlation between the slow-time PA profiles measured from the two beams, the speed and direction of transverse flow are simultaneously derived from the magnitude and sign of the time shift, respectively. Transverse flows in the range of 0.50 to 6.84\u2009\u2009mm/s 6.84\u2009\u2009mm/s are accurately measured using an aqueous suspension of 10-\u03bcm-diameter microspheres, and the root-mean-squared measurement accuracy is quantified to be 0.22\u2009\u2009mm/s \n0.22\u2009\u2009mm/s. The flow measurements are independent of the particle size for flows in the velocity range of 0.55 to 6.49\u2009\u2009mm/s \n6.49\u2009\u2009mm/s, which was demonstrated experimentally using three different sizes of microspheres (diameters: 3, 6, and 10 \u03bcm). The measured flow velocity follows an expected parabolic distribution along the depth direction perpendicular to the flow. Both maximum and minimum measurable velocities are investigated for varied distances between the two beams and varied total time for one measurement. This technique shows an accuracy of 0.35\u2009\u2009mm/s \n0.35\u2009\u2009mm/s at 0.3-mm depth in scattering chicken breast, making it promising for measuring flow in biological tissue.",
"doi": "10.1117/1.JBO.18.9.096004",
"pmcid": "PMC3763964",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2013-09",
"series_number": "9",
"volume": "18",
"issue": "9",
"pages": "Art. No. 096004"
},
{
"id": "authors:3gk9z-s3m12",
"collection": "authors",
"collection_id": "3gk9z-s3m12",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-125741779",
"type": "article",
"title": "Photoacoustic microscopy",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic microscopy (PAM) is a hybrid in vivo imaging technique that acoustically detects optical contrast via the photoacoustic effect. Unlike pure optical microscopic techniques, PAM takes advantage of the weak acoustic scattering in tissue and thus breaks through the optical diffusion limit (\u223c1 mm in soft tissue). With its excellent scalability, PAM can provide high-resolution images at desired maximum imaging depths up to a few millimeters. Compared with backscattering-based confocal microscopy and optical coherence tomography, PAM provides absorption contrast instead of scattering contrast. Furthermore, PAM can image more molecules, endogenous or exogenous, at their absorbing wavelengths than fluorescence-based methods, such as wide-field, confocal, and multi-photon microscopy. Most importantly, PAM can simultaneously image anatomical, functional, molecular, flow dynamic and metabolic contrasts in vivo. Focusing on state-of-the-art developments in PAM, this Review discusses the key features of PAM implementations and their applications in biomedical studies.",
"doi": "10.1002/lpor.201200060",
"pmcid": "PMC3887369",
"issn": "1863-8880",
"publisher": "Wiley",
"publication": "Laser and Photonics Reviews",
"publication_date": "2013-09",
"series_number": "5",
"volume": "7",
"issue": "5",
"pages": "758-778"
},
{
"id": "authors:3h56c-f3w65",
"collection": "authors",
"collection_id": "3h56c-f3w65",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160614-091904154",
"type": "article",
"title": "Focusing light into tissue",
"author": [
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Lai",
"given_name": "Puxiang",
"clpid": "Lai-Puxiang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A novel technique uses ultrasonic encoding and time reversal to break\nthe diffusion limit and enable optical imaging, manipulation, and\ntherapy at greater depths.",
"doi": "10.1117/2.1201308.004937",
"issn": "1818-2259",
"publisher": "SPIE",
"publication": "SPIE Newsroom",
"publication_date": "2013-08-28",
"pages": "Art. No. 4937"
},
{
"id": "authors:wmhn3-7rs71",
"collection": "authors",
"collection_id": "wmhn3-7rs71",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160706-130609163",
"type": "article",
"title": "Structured-illumination photoacoustic Doppler flowmetry of axial flow in homogeneous scattering media",
"author": [
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We propose a method for photoacoustic flow measurement based on the Doppler effect from a flowing homogeneous medium. Excited by spatially modulated laser pulses, the flowing medium induces a Doppler frequency shift in the received photoacoustic signals. The frequency shift is proportional to the component of the flow speed projected onto the acoustic beam axis, and the sign of the shift reflects the flow direction. Unlike conventional flowmetry, this method does not rely on particle heterogeneity in the medium; thus, it can tolerate extremely high particle density. A red-ink phantom flowing in a tube immersed in water was used to validate the method in both the frequency and time domains. The phantom flow immersed in an intralipid solution was also measured.",
"doi": "10.1063/1.4819735",
"pmcid": "PMC3772904",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2013-08-26",
"series_number": "9",
"volume": "103",
"issue": "9",
"pages": "Art. No. 094101"
},
{
"id": "authors:y0eq7-cqx98",
"collection": "authors",
"collection_id": "y0eq7-cqx98",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160706-131727609",
"type": "article",
"title": "Optical-Resolution Photoacoustic Microscopy: Auscultation of Biological Systems at the Cellular Level",
"author": [
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic microscopy (PAM) offers unprecedented sensitivity to optical absorption and opens a new window to study biological systems at multiple length- and timescales. In particular, optical-resolution PAM (OR-PAM) has pushed the technical envelope to submicron length scales and millisecond timescales. Here, we review the state of the art of OR-PAM in biophysical research. With properly chosen optical wavelengths, OR-PAM can spectrally differentiate a variety of endogenous and exogenous chromophores, unveiling the anatomical, functional, metabolic, and molecular information of biological systems. Newly uncovered contrast mechanisms of linear dichroism and F\u00f6rster resonance energy transfer further distinguish OR-PAM. Integrating multiple contrasts and advanced scanning mechanisms has capacitated OR-PAM to comprehensively interrogate biological systems at the cellular level in real time. Two future directions are discussed, where OR-PAM holds the potential to translate basic biophysical research into clinical healthcare.",
"doi": "10.1016/j.bpj.2013.07.017",
"pmcid": "PMC3752103",
"issn": "0006-3495",
"publisher": "Biophysical Society",
"publication": "Biophysical Journal",
"publication_date": "2013-08-20",
"series_number": "4",
"volume": "105",
"issue": "4",
"pages": "841-847"
},
{
"id": "authors:jsqf1-t0r63",
"collection": "authors",
"collection_id": "jsqf1-t0r63",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160727-093707118",
"type": "article",
"title": "Enhancement of photoacoustic tomography by ultrasonic computed tomography based on optical excitation of elements of a full-ring transducer array",
"author": [
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Huang",
"given_name": "Chao",
"clpid": "Huang-Chao"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic computed tomography (PACT) is a hybrid technique that combines optical excitation and ultrasonic detection to provide high-resolution images in deep tissues. In the image reconstruction, a constant speed of sound (SOS) is normally assumed. This assumption, however, is often not strictly satisfied in deep tissue imaging, due to acoustic heterogeneities within the object and between the object and the coupling medium. If these heterogeneities are not accounted for, they will cause distortions and artifacts in the reconstructed images. In this Letter, we incorporated ultrasonic computed tomography (USCT), which measures the SOS distribution within the object, into our full-ring array PACT system. Without the need for ultrasonic transmitting electronics, USCT was performed using the same laser beam as for PACT measurement. By scanning the laser beam on the array surface, we can sequentially fire different elements. As a first demonstration of the system, we studied the effect of acoustic heterogeneities on photoacoustic vascular imaging. We verified that constant SOS is a reasonable approximation when the SOS variation is small. When the variation is large, distortion will be observed in the periphery of the object, especially in the tangential direction.",
"doi": "10.1364/OL.38.003140",
"pmcid": "PMC3884569",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2013-08-15",
"series_number": "16",
"volume": "38",
"issue": "16",
"pages": "3140-3143"
},
{
"id": "authors:dtehm-2am86",
"collection": "authors",
"collection_id": "dtehm-2am86",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160805-133116641",
"type": "article",
"title": "Random-access optical-resolution photoacoustic microscopy using a digital micromirror device",
"author": [
{
"family_name": "Liang",
"given_name": "Jinyang",
"clpid": "Liang-Jinyang"
},
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Winkler",
"given_name": "Amy W.",
"clpid": "Winkler-A-W"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We developed random-access optical-resolution photoacoustic microscopy using a digital micromirror device. This system can rapidly scan arbitrarily shaped regions of interest within a 40\u2009\u2009\u03bcm\u00d740\u2009\u2009\u03bcm imaging area with a lateral resolution of 3.6 \u03bcm. To identify a region of interest, a global structural image is first acquired, then the selected region is scanned. The random-access ability was demonstrated by imaging two static samples, a carbon fiber cross and a monolayer of red blood cells, with an acquisition rate up to 4 kHz. The system was then used to monitor blood flow in vivo in real time within user-selected capillaries in a mouse ear. By imaging only the capillary of interest, the frame rate was increased by up to 9.2 times.",
"doi": "10.1364/OL.38.002683",
"pmcid": "PMC3784350",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2013-08-01",
"series_number": "15",
"volume": "38",
"issue": "15",
"pages": "2683-2686"
},
{
"id": "authors:as6vg-3wa13",
"collection": "authors",
"collection_id": "as6vg-3wa13",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160726-132754559",
"type": "article",
"title": "Calibration-free quantification of absolute oxygen saturation based on the dynamics of photoacoustic signals",
"author": [
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Danielli",
"given_name": "Amos",
"clpid": "Danielli-A"
},
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) is a hybrid imaging technique that has broad preclinical and clinical applications. Based on the photoacoustic effect, PAT directly measures specific optical absorption, which is the product of the tissue-intrinsic optical absorption coefficient and the local optical fluence. Therefore, quantitative PAT, such as absolute oxygen saturation (sO_2) quantification, requires knowledge of the local optical fluence, which can only be estimated through invasive measurements or sophisticated modeling of light transportation. In this Letter, we circumvent this requirement by taking advantage of the dynamics in sO_2. The new method works when the sO_2 transition can be simultaneously monitored with multiple wavelengths. For each wavelength, the ratio of photoacoustic amplitudes measured at different sO_2 states is utilized. Using the ratio cancels the contribution from optical fluence and allows calibration-free quantification of absolute sO_2. The new method was validated through both phantom and in vivo experiments.",
"doi": "10.1364/OL.38.002800",
"pmcid": "PMC3884570",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2013-08-01",
"series_number": "15",
"volume": "38",
"issue": "15",
"pages": "2800-2803"
},
{
"id": "authors:v96f9-4z218",
"collection": "authors",
"collection_id": "v96f9-4z218",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160803-125101886",
"type": "article",
"title": "Labeling Human Mesenchymal Stem Cells with Gold Nanocages for in vitro and in vivo Tracking by Two-Photon Microscopy and Photoacoustic Microscopy",
"author": [
{
"family_name": "Zhang",
"given_name": "Yu Shrike",
"clpid": "Zhang-Yu-Shrike"
},
{
"family_name": "Wang",
"given_name": "Yu",
"orcid": "0000-0003-3589-9274",
"clpid": "Wang-Yu"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Wang",
"given_name": "Yucai",
"clpid": "Wang-Yucai"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "Stem cell tracking is a highly important subject. Current techniques based on nanoparticle-labeling, such as magnetic resonance imaging, fluorescence microscopy, and micro-computed tomography, are plagued by limitations including relatively low sensitivity or penetration depth, involvement of ionizing irradiation, and potential cytotoxicity of the nanoparticles. Here we introduce a new class of contrast agents based on gold nanocages (AuNCs) with hollow interiors and porous walls to label human mesenchymal stem cells (hMSCs) for both in vitro and in vivo tracking using two-photon microscopy and photoacoustic microscopy. As demonstrated by the viability assay, the AuNCs showed negligible cytotoxicity under a reasonable dose, and did not alter the differentiation potential of the hMSCs into desired lineages. We were able to image the cells labeled with AuNCs in vitro for at least 28 days in culture, as well as to track the cells that homed to the tumor region in nude mice in vivo.",
"doi": "10.7150/thno.5369",
"pmcid": "PMC3741603",
"issn": "1838-7640",
"publisher": "Ivyspring International Publisher",
"publication": "Theranostics",
"publication_date": "2013-08",
"series_number": "8",
"volume": "3",
"issue": "8",
"pages": "532-543"
},
{
"id": "authors:5pnmq-bs246",
"collection": "authors",
"collection_id": "5pnmq-bs246",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160803-152446270",
"type": "article",
"title": "Optical clearing-aided photoacoustic microscopy with enhanced resolution and imaging depth",
"author": [
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Due to strong light scattering in tissue, both the spatial resolution and maximum penetration depth of optical-resolution photoacoustic microscopy (OR-PAM) deteriorate sharply with depth. To reduce tissue scattering, we propose to use glycerol as an optical clearing agent in OR-PAM. Our results show that the imaging performance of OR-PAM can be greatly enhanced by optical clearing both in vitro and in vivo.",
"doi": "10.1364/OL.38.002592",
"pmcid": "PMC3759812",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2013-07-15",
"series_number": "14",
"volume": "38",
"issue": "14",
"pages": "2592-2595"
},
{
"id": "authors:sbdvx-3nx52",
"collection": "authors",
"collection_id": "sbdvx-3nx52",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160727-094611789",
"type": "article",
"title": "Focused fluorescence excitation with time-reversed ultrasonically encoded light and imaging in thick scattering media",
"author": [
{
"family_name": "Lai",
"given_name": "Puxiang",
"clpid": "Lai-Puxiang"
},
{
"family_name": "Suzuki",
"given_name": "Yuta",
"clpid": "Suzuki-Yuta"
},
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Scattering dominates light propagation in biological tissue, and therefore restricts both resolution and penetration depth in optical imaging within thick tissue. As photons travel into the diffusive regime, typically 1 mm beneath human skin, their trajectories transition from ballistic to diffusive due to the increased number of scattering events, which makes it impossible to focus, much less track, photon paths. Consequently, imaging methods that rely on controlled light illumination are ineffective in deep tissue. This problem has recently been addressed by a novel method capable of dynamically focusing light in thick scattering media via time reversal of ultrasonically encoded (TRUE) diffused light. Here, using photorefractive materials as phase conjugate mirrors, we show a direct visualization and dynamic control of optical focusing with this light delivery method, and demonstrate its application for focused fluorescence excitation and imaging in thick turbid media. These abilities are increasingly critical for understanding the dynamic interactions of light with biological matter and processes at different system levels, as well as their applications for biomedical diagnosis and therapy.",
"doi": "10.1088/1612-2011/10/7/075604",
"pmcid": "PMC3900304",
"issn": "1612-2011",
"publisher": "IOP Publishing",
"publication": "Laser Physics Letters",
"publication_date": "2013-07",
"series_number": "7",
"volume": "10",
"issue": "7",
"pages": "Art. No. 075604"
},
{
"id": "authors:zgr2x-kmw09",
"collection": "authors",
"collection_id": "zgr2x-kmw09",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160805-131858122",
"type": "article",
"title": "Photoacoustic and optical coherence tomography of epilepsy with high temporal and spatial resolution and dual optical contrasts",
"author": [
{
"family_name": "Tsytsarev",
"given_name": "Vassiliy",
"clpid": "Tsytsarev-V"
},
{
"family_name": "Rao",
"given_name": "Bin",
"orcid": "0000-0001-6494-3110",
"clpid": "Rao-Bin"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Li",
"given_name": "Li",
"clpid": "Li-Li"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Epilepsy mapping with high spatial and temporal resolution has great significance for both fundamental research on epileptic neurons and the clinical management of epilepsy. In this communication, we demonstrate for the first time in vivo epilepsy mapping with high spatial and temporal resolution and dual optical contrasts in an animal model. Through the variations of a depthresolved optical coherence tomography signal with optical scattering contrast, we observed that epileptic neuron activities modulated the optical refractive index of epileptic neurons and their surrounding tissue. Simultaneously, through neurovasculature coupling mechanisms and optical absorption contrast, we used photoacoustic signals to document the hemodynamic changes of the microvasculature surrounding the epileptic neurons. The epilepsy mapping results were confirmed by a simultaneously recorded electroencephalogram signal during epileptic seizure. Our new epilepsy mapping tool, with high temporal and spatial resolution and dual optical contrasts, may find many applications, such as drug development and epilepsy surgery.",
"doi": "10.1016/j.jneumeth.2013.04.001",
"pmcid": "PMC3695704",
"issn": "0165-0270",
"publisher": "Elsevier",
"publication": "Journal of Neuroscience Methods",
"publication_date": "2013-06-15",
"series_number": "2",
"volume": "216",
"issue": "2",
"pages": "142-145"
},
{
"id": "authors:7w1qz-byj24",
"collection": "authors",
"collection_id": "7w1qz-byj24",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-142857269",
"type": "article",
"title": "Up-regulation of hypoxia-inducible factor 1 alpha and hemodynamic responses following massive small bowel resection",
"author": [
{
"family_name": "Rowland",
"given_name": "Kathryn J.",
"clpid": "Rowland-K-J"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Erwin",
"given_name": "Christopher R.",
"clpid": "Erwin-C-R"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Warner",
"given_name": "Brad W.",
"clpid": "Warner-B-W"
}
],
"abstract": "Purpose:\nMassive small bowel resection (SBR) results in an adaptive response within the remnant bowel. We have previously shown an immediate reduction in intestinal blood flow and oxygen saturation (sO_2) after SBR. We therefore sought to determine the duration of resection-induced intestinal hypoxia and expression of hypoxia-inducible factors (HIFs) following SBR.\nMethods:\nC57B6 mice were subjected to 50% proximal SBR or a sham procedure. Photoacoustic microscopy (PAM) was used to measure blood flow and sO_2 on postoperative days (PODs) 1, 3, and 7. Ileal tissue was harvested 6 h postoperatively and on PODs 1 and 2, and HIF1\u03b1, HIF2\u03b1, and VEGF mRNA expression were assessed via RT-PCR. A p value of less than 0.05 was considered significant.\nResults:\nFollowing SBR, reduction in intestinal blood flow persists for 24 h and is followed with hyperemia by POD 3. The immediate reduction in venous sO_2 and increased tissue oxygen utilization continued through POD 7. Enhanced expression of HIF1\u03b1 was demonstrated 6 h following SBR.\nConclusion:\nMassive SBR results in an immediate relative hypoxic state within the remnant bowel with early enhanced expression of HIF1\u03b1. On POD 7, increased tissue oxygen extraction and elevated blood flow persist in the adapting intestine.",
"doi": "10.1016/j.jpedsurg.2013.03.031",
"pmcid": "PMC3755458",
"issn": "0022-3468",
"publisher": "Elsevier",
"publication": "Journal of Pediatric Surgery",
"publication_date": "2013-06",
"series_number": "6",
"volume": "48",
"issue": "6",
"pages": "1330-1339"
},
{
"id": "authors:btzmf-vmd47",
"collection": "authors",
"collection_id": "btzmf-vmd47",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190227-140300562",
"type": "article",
"title": "Photothermal bleaching in time\u2010lapse photoacoustic microscopy",
"author": [
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We studied the phenomenon of photothermal bleaching \u2013 a gradual reduction of contrast agent particles during repeated scans in photoacoustic microscopy. The dependence of the photothermal bleaching rate on the excitation pulse energy, pulse duration, and the absorber's size was determined while the laser focal diameter was held constant. Our results showed that, the dependence of the photothermal bleaching rate on the excitation pulse energy differed before and after the absorbers were raised to their melting point by the deposited laser energy. Based on this finding, we suggested an optimal excitation pulse energy, which balances the photothermal bleaching rate and signal amplitude, for time\u2010lapse imaging applications.",
"doi": "10.1002/jbio.201200184",
"pmcid": "PMC3901079",
"issn": "1864-063X",
"publisher": "Wiley-VCH",
"publication": "Journal of Biophotonics",
"publication_date": "2013-06",
"series_number": "6-7",
"volume": "6",
"issue": "6-7",
"pages": "543-548"
},
{
"id": "authors:vks7q-0vb77",
"collection": "authors",
"collection_id": "vks7q-0vb77",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160727-101845822",
"type": "article",
"title": "Full-Wave Iterative Image Reconstruction in Photoacoustic Tomography With Acoustically Inhomogeneous Media",
"author": [
{
"family_name": "Huang",
"given_name": "Chao",
"clpid": "Huang-Chao"
},
{
"family_name": "Wang",
"given_name": "Kun",
"clpid": "Wang-Kun"
},
{
"family_name": "Nie",
"given_name": "Liming",
"clpid": "Nie-Liming"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
}
],
"abstract": "Existing approaches to image reconstruction in photoacoustic computed tomography (PACT) with acoustically heterogeneous media are limited to weakly varying media, are computationally burdensome, and/or cannot effectively mitigate the effects of measurement data incompleteness and noise. In this work, we develop and investigate a discrete imaging model for PACT that is based on the exact photoacoustic (PA) wave equation and facilitates the circumvention of these limitations. A key contribution of the work is the establishment of a procedure to implement a matched forward and backprojection operator pair associated with the discrete imaging model, which permits application of a wide-range of modern image reconstruction algorithms that can mitigate the effects of data incompleteness and noise. The forward and backprojection operators are based on the k-space pseudospectral method for computing numerical solutions to the PA wave equation in the time domain. The developed reconstruction methodology is investigated by use of both computer-simulated and experimental PACT measurement data.",
"doi": "10.1109/TMI.2013.2254496",
"pmcid": "PMC4114232",
"issn": "0278-0062",
"publisher": "IEEE",
"publication": "IEEE Transactions on Medical Imaging",
"publication_date": "2013-06",
"series_number": "6",
"volume": "32",
"issue": "6",
"pages": "1097-1110"
},
{
"id": "authors:56xph-9yd62",
"collection": "authors",
"collection_id": "56xph-9yd62",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-135652393",
"type": "article",
"title": "Intracellular temperature mapping with fluorescence-assisted photoacoustic-thermometry",
"author": [
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Measuring intracellular temperature is critical to understanding many cellular functions but still remains challenging. Here, we present a technique\u2013fluorescence-assisted photoacoustic thermometry (FAPT)\u2013for intracellular temperature mapping applications. To demonstrate FAPT, we monitored the intracellular temperature distribution of HeLa cells with sub-degree (0.7\u2009\u00b0C) temperature resolution and sub-micron (0.23\u2009\u03bcm) spatial resolution at a sampling rate of 1\u2009kHz. Compared to traditional fluorescence-based methods, FAPT features the unique capability of transforming a regular fluorescence probe into a concentration- and excitation-independent temperature sensor, bringing a large collection of commercially available generic fluorescent probes into the realm of intracellular temperature sensing.",
"doi": "10.1063/1.4807140",
"pmcid": "PMC3669113",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2013-05-13",
"series_number": "19",
"volume": "102",
"issue": "19",
"pages": "Art. No. 193705"
},
{
"id": "authors:h0yeq-tyk15",
"collection": "authors",
"collection_id": "h0yeq-tyk15",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-101623847",
"type": "article",
"title": "A green synthesis of carbon nanoparticles from honey and their use in real-time photoacoustic imaging",
"author": [
{
"family_name": "Wu",
"given_name": "Lina",
"clpid": "Wu-Lina"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Nelson",
"given_name": "Kate",
"clpid": "Nelson-K"
},
{
"family_name": "Xing",
"given_name": "Wenxin",
"clpid": "Xing-Wenxin"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Zhang",
"given_name": "Ruiying",
"orcid": "0000-0002-0092-0814",
"clpid": "Zhang-Ruiying"
},
{
"family_name": "Stacy",
"given_name": "Allen J.",
"clpid": "Stacy-A-J"
},
{
"family_name": "Luderer",
"given_name": "Micah",
"clpid": "Luderer-M"
},
{
"family_name": "Lanza",
"given_name": "Gregory M.",
"clpid": "Lanza-G-M"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Shen",
"given_name": "Baozhong",
"clpid": "Shen-Baozhong"
},
{
"family_name": "Pan",
"given_name": "Dipanjan",
"clpid": "Pan-Dipanjan"
}
],
"abstract": "Imaging sentinel lymph nodes (SLN) could provide us with critical information about the progression of a cancerous disease. Real-time high-resolution intraoperative photoacoustic imaging (PAI) in conjunction with a near-infrared (NIR) probe may offer opportunities for the immediate imaging for direct identification and resection of SLN or collecting tissue samples. In this work a commercially amenable synthetic methodology is revealed for fabricating luminescent carbon nanoparticles with rapid clearance properties. A one-pot \"green\" technique is pursued, which involved rapid surface passivation of carbon nanoparticles with organic macromolecules (e.g., polysorbate, polyethyleneglycol) in solvent-free conditions. Interestingly, the naked carbon nanoparticles are derived for the first time, from commercial food grade honey. Surface coated particles are markedly smaller (\u223c7 nm) than previously explored particles (gold, single-walled carbon nanotubes, copper) for SLN imaging. The results indicate an exceptionally rapid signal enhancement (\u223c2 min) of the SLN. Owing to their strong optical absorption in the NIR region, tiny size and rapid lymphatic transport, this platform offers great potential for faster resection of SLN and may lower complications caused in axillary investigation by mismarking with dyes or low-resolution imaging techniques.",
"doi": "10.1007/s12274-013-0308-8",
"pmcid": "PMC3696503",
"issn": "1998-0124",
"publisher": "Springer",
"publication": "Nano Research",
"publication_date": "2013-05",
"series_number": "5",
"volume": "6",
"issue": "5",
"pages": "312-325"
},
{
"id": "authors:314x8-6bp72",
"collection": "authors",
"collection_id": "314x8-6bp72",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160701-123400226",
"type": "article",
"title": "Slow-sound photoacoustic microscopy",
"author": [
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We propose to enhance the axial resolution of photoacoustic microscopy (PAM) by reducing the speed of sound within the imaging region of interest. With silicone oil immersion, we have achieved a finest axial resolution of 5.8\u2009\u03bcm for PAM, as validated by phantom experiments. The axial resolution was also enhanced in vivo when mouse ears injected with silicone oil were imaged. When tissue-compatible low-speed liquid becomes available, this approach may find broad applications in PAM as well as in other imaging modalities, such as photoacoustic computed tomography and ultrasound imaging.",
"doi": "10.1063/1.4803444",
"pmcid": "PMC3651204",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2013-04-22",
"series_number": "16",
"volume": "102",
"issue": "16",
"pages": "Art. No. 163702"
},
{
"id": "authors:md1x4-fr645",
"collection": "authors",
"collection_id": "md1x4-fr645",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160614-124115973",
"type": "article",
"title": "Single-cell label-free photoacoustic flowoxigraphy in vivo",
"author": [
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Label-free functional imaging of single red blood cells (RBCs) in vivo holds the key to uncovering the fundamental mechanism of oxygen metabolism in cells. To this end, we developed single-RBC photoacoustic flowoxigraphy (FOG), which can image oxygen delivery from single flowing RBCs in vivo with millisecond-scale temporal resolution and micrometer-scale spatial resolution. Using intrinsic optical absorption contrast from oxyhemoglobin (HbO_2) and deoxyhemoglobin (HbR), FOG allows label-free imaging. Multiple single-RBC functional parameters, including total hemoglobin concentration (C_(Hb)), oxygen saturation (sO_2), sO_2 gradient (\u2207SO_2), flow speed (v_f), and oxygen release rate (rO_2), have been quantified simultaneously in real time. Working in reflection instead of transmission mode, the system allows minimally invasive imaging at more anatomical sites. We showed the capability to measure relationships among sO_2, \u2207SO_2, v_f, and rO_2 in a living mouse brain. We also demonstrated that single-RBC oxygen delivery was modulated by changing either the inhalation gas or blood glucose. Furthermore, we showed that the coupling between neural activity and oxygen delivery could be imaged at the single-RBC level in the brain. The single-RBC functional imaging capability of FOG enables numerous biomedical studies and clinical applications.",
"doi": "10.1073/pnas.1215578110",
"pmcid": "PMC3625281",
"issn": "0027-8424",
"publisher": "National Academy of Sciences",
"publication": "Proceedings of the National Academy of Sciences of the United States of America",
"publication_date": "2013-04-09",
"series_number": "15",
"volume": "110",
"issue": "15",
"pages": "5759-5764"
},
{
"id": "authors:9t7tb-5h591",
"collection": "authors",
"collection_id": "9t7tb-5h591",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160708-150736109",
"type": "article",
"title": "A water-immersible 2-axis scanning mirror microsystem for ultrasound and photoacoustic microscopic imaging applications",
"author": [
{
"family_name": "Huang",
"given_name": "Chih-Hsien",
"clpid": "Huang-Chih-Hsien"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Zou",
"given_name": "Jun",
"orcid": "0000-0002-9543-6135",
"clpid": "Zou-Jun"
}
],
"abstract": "Fast scanning is highly desired for both ultrasound and photoacoustic microscopic imaging, whereas the liquid environment required for acoustic propagation limits the usage of traditional microelectromechanical systems (MEMS) scanning mirrors. Here, a new water-immersible scanning mirror microsystem has been designed, fabricated and tested. To achieve reliable underwater scanning, flexible polymer torsion hinges fabricated by laser micromachining were used to support the reflective silicon mirror plate. Two efficient electromagnetic microactuators consisting of compact RF choke inductors and high-strength neodymium magnet disc were constructed to drive the silicon mirror plate around a fast axis and a slow axis. The performance of this water-immersible scanning mirror microsystem in both air and water were tested using the laser tracing method. For the fast axis, the resonance frequency reached 224 Hz in air and 164 Hz in water, respectively. The scanning angles in both air and water under \u00b116 V DC driving were \u00b112\u00b0. The scanning angles in air and water under \u00b110 V AC driving (at the resonance frequencies) were \u00b113.6\u00b0 and \u00b110\u00b0. For the slow axis, the resonance frequency reached 55 Hz in air and 38 Hz in water, respectively. The scanning angles in both air and water under \u00b110 V DC driving were \u00b16.5\u00b0. The scanning angles in air and water under \u00b110 V AC driving (at the resonance frequencies) were \u00b18.5\u00b0 and \u00b16\u00b0. The feasibility of using such a water-immersible scanning mirror microsystem for scanning ultrasound microscopic imaging has been demonstrated with a 25-MHz ultrasound pulse/echo system and a target consisting of three optical fibers.",
"doi": "10.1007/s00542-012-1660-4",
"issn": "0946-7076",
"publisher": "Springer",
"publication": "Microsystem Technologies",
"publication_date": "2013-04",
"series_number": "4",
"volume": "19",
"issue": "4",
"pages": "577-582"
},
{
"id": "authors:g14zk-qxt57",
"collection": "authors",
"collection_id": "g14zk-qxt57",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160726-152910222",
"type": "article",
"title": "Comparison Study of Gold Nanohexapods, Nanorods, and Nanocages for Photothermal Cancer Treatment",
"author": [
{
"family_name": "Wang",
"given_name": "Yucai",
"clpid": "Wang-Yucai"
},
{
"family_name": "Black",
"given_name": "Kvar C. L.",
"clpid": "Black-K-C-L"
},
{
"family_name": "Luehmann",
"given_name": "Hannah",
"clpid": "Luehmann-H-P"
},
{
"family_name": "Li",
"given_name": "Weiyang",
"clpid": "Li-Weiyang"
},
{
"family_name": "Zhang",
"given_name": "Yu",
"orcid": "0000-0001-8938-1927",
"clpid": "Zhang-Yu"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Wan",
"given_name": "Dehui",
"clpid": "Wan-Dehui"
},
{
"family_name": "Liu",
"given_name": "Si-Yun",
"clpid": "Liu-Si-Yun"
},
{
"family_name": "Li",
"given_name": "Max",
"clpid": "Li-Max"
},
{
"family_name": "Kim",
"given_name": "Paul",
"clpid": "Kim-Paul"
},
{
"family_name": "Li",
"given_name": "Zhi-Yuan",
"clpid": "Li-Zhi-Yuan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Liu",
"given_name": "Yongjian",
"clpid": "Liu-Yongjian"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "Gold nanohexapods represent a novel class of optically tunable nanostructures consisting of an octahedral core and six arms grown on its vertices. By controlling the length of the arms, their localized surface plasmon resonance peaks could be tuned from the visible to the near-infrared region for deep penetration of light into soft tissues. Herein we compare the in vitro and in vivo capabilities of Au nanohexapods as photothermal transducers for theranostic applications by benchmarking against those of Au nanorods and nanocages. While all these Au nanostructures could absorb and convert near-infrared light into heat, Au nanohexapods exhibited the highest cellular uptake and the lowest cytotoxicity in vitro for both the as-prepared and PEGylated nanostructures. In vivo pharmacokinetic studies showed that the PEGylated Au nanohexapods had significant blood circulation and tumor accumulation in a mouse breast cancer model. Following photothermal treatment, substantial heat was produced in situ and the tumor metabolism was greatly reduced for all these Au nanostructures, as determined with ^(18)F-flourodeoxyglucose positron emission tomography/computed tomography (^(18)F-FDG PET/CT). Combined together, we can conclude that Au nanohexapods are promising candidates for cancer theranostics in terms of both photothermal destruction and contrast-enhanced diagnosis.",
"doi": "10.1021/nn304332s",
"pmcid": "PMC3609935",
"issn": "1936-0851",
"publisher": "American Chemical Society",
"publication": "ACS Nano",
"publication_date": "2013-03-26",
"series_number": "3",
"volume": "7",
"issue": "3",
"pages": "2068-2077"
},
{
"id": "authors:38rvn-6g114",
"collection": "authors",
"collection_id": "38rvn-6g114",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160803-102318515",
"type": "article",
"title": "High-sensitivity ultrasound-modulated optical tomography with a photorefractive polymer",
"author": [
{
"family_name": "Suzuki",
"given_name": "Yuta",
"clpid": "Suzuki-Yuta"
},
{
"family_name": "Lai",
"given_name": "Puxiang",
"clpid": "Lai-Puxiang"
},
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "By detecting ultrasonically tagged diffuse light, ultrasound-modulated optical tomography images optical contrast with ultrasonic resolution deep in turbid media, such as biological tissue. However, small detection etendues and weak tagged light submerged in strong untagged background light limit the signal detection sensitivity. In this Letter, we report the use of a large-area (\u223c5\u2009cm\u00d75\u2009cm\u2009) photorefractive polymer film that yields more than 10 times detection etendue over previous detection schemes. Our polymer-based system enabled us to resolve absorbing objects embedded inside diffused media thicker than 80 transport mean free paths, by using moderate light power and short ultrasound pulses.",
"doi": "10.1364/OL.38.000899",
"pmcid": "PMC3626994",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2013-03-15",
"series_number": "6",
"volume": "38",
"issue": "6",
"pages": "899-901"
},
{
"id": "authors:rbwbs-tfk68",
"collection": "authors",
"collection_id": "rbwbs-tfk68",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160809-081758617",
"type": "article",
"title": "Virus-mimicking nano-constructs as a contrast agent for near infrared photoacoustic imaging",
"author": [
{
"family_name": "Gupta",
"given_name": "Sharad",
"clpid": "Gupta-S"
},
{
"family_name": "Chatni",
"given_name": "Muhammad R.",
"clpid": "Chatni-M-R"
},
{
"family_name": "Rao",
"given_name": "Ayala L. N.",
"clpid": "Rao-A-L-N"
},
{
"family_name": "Vullev",
"given_name": "Valentine I.",
"clpid": "Vullev-V-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Anvari",
"given_name": "Bahman",
"clpid": "Anvari-B"
}
],
"abstract": "We report the first proof-of-principle demonstration of photoacoustic imaging using a contrast agent composed of a plant virus protein shell, which encapsulates indocyanine green (ICG), the only FDA-approved near infrared chromophore. These nano-constructs can provide higher photoacoustic signals than blood in tissue phantoms, and display superior photostability compared to non-encapsulated ICG. Our preliminary results suggest that the constructs do not elicit an acute immunogenic response in healthy mice.",
"doi": "10.1039/c3nr34124k",
"pmcid": "PMC3626106",
"issn": "2040-3364",
"publisher": "Royal Society of Chemistry",
"publication": "Nanoscale",
"publication_date": "2013-03-07",
"series_number": "5",
"volume": "5",
"issue": "5",
"pages": "1772-1776"
},
{
"id": "authors:e85g6-gad26",
"collection": "authors",
"collection_id": "e85g6-gad26",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160805-153830149",
"type": "article",
"title": "Reflection-mode multifocal optical-resolution photoacoustic microscopy",
"author": [
{
"family_name": "Li",
"given_name": "Guo",
"clpid": "Li-Guo"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Compared with single-focus optical-resolution photoacoustic microscopy (OR-PAM), multifocal OR-PAM utilizes both multifocal optical illumination and an ultrasonic array transducer, significantly increasing the imaging speed. A reflection-mode multifocal OR-PAM system based on a microlens array that provides multiple foci as well as an ultrasonic array transducer that receives the excited photoacoustic waves from all foci simultaneously is presented. Using a customized microprism to reflect the incident laser beam to the microlens array, the multiple optical foci are aligned confocally with the focal zone of the ultrasonic array transducer. Experiments show the reflection-mode multifocal OR-PAM is capable of imaging microvessels in vivo, and it can image a 6\u00d75\u00d72.5\u2009\u2009mm^3 volume at 16 \u03bcm lateral resolution in \u223c2.5\u2009\u2009min, which was limited by the signal multiplexing ratio and laser pulse repetition rate.",
"doi": "10.1117/1.JBO.18.3.030501",
"pmcid": "PMC3582721",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2013-03",
"series_number": "3",
"volume": "18",
"issue": "3",
"pages": "Art. No. 030501"
},
{
"id": "authors:pmcq0-2kw53",
"collection": "authors",
"collection_id": "pmcq0-2kw53",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160711-124717717",
"type": "article",
"title": "Photoacoustic microscopy in tissue engineering",
"author": [
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Zhang",
"given_name": "Yu Shrike",
"clpid": "Zhang-Yu-Shrike"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) is an attractive modality for noninvasive, volumetric imaging of scattering media such as biological tissues. By choosing the ultrasonic detection frequency, PAT enables scalable spatial resolution with an imaging depth of up to \u223c7 cm while maintaining a high depth-to-resolution ratio of \u223c200 and consistent optical absorption contrasts. Photoacoustic microscopy (PAM), the microscopic embodiment of PAT, aims to image at millimeter depth and micrometer-scale resolution. PAM is well-suited for characterizing three-dimensional scaffold-based samples, including scaffolds themselves, cells, and blood vessels, both qualitatively and quantitatively. Here we review our previous work on applications of PAM in tissue engineering and then discuss its future developments.",
"doi": "10.1016/j.mattod.2013.03.007",
"pmcid": "PMC3678877",
"issn": "1369-7021",
"publisher": "Elsevier",
"publication": "Materials Today",
"publication_date": "2013-03",
"series_number": "3",
"volume": "16",
"issue": "3",
"pages": "67-77"
},
{
"id": "authors:p02cq-3j715",
"collection": "authors",
"collection_id": "p02cq-3j715",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-124239206",
"type": "article",
"title": "Investigation of Neovascularization in Three-Dimensional Porous Scaffolds In Vivo by a Combination of Multiscale Photoacoustic Microscopy and Optical Coherence Tomography",
"author": [
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Zhang",
"given_name": "Yu",
"orcid": "0000-0001-8938-1927",
"clpid": "Zhang-Yu"
},
{
"family_name": "Li",
"given_name": "Li",
"clpid": "Li-Li"
},
{
"family_name": "Choi",
"given_name": "Sung-Wook",
"clpid": "Choi-Sung-Wook"
},
{
"family_name": "MacEwan",
"given_name": "Matthew R.",
"clpid": "MacEwan-M-R"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "It is a grand challenge to visualize and assess in vivo neovascularization in a three-dimensional (3D) scaffold noninvasively, together with high spatial resolution and deep penetration depth. Here we used multiscale photoacoustic microscopy (PAM), including acoustic-resolution PAM (AR-PAM) and optical-resolution PAM (OR-PAM), to chronically monitor neovascularization in an inverse opal scaffold implanted in a mouse model up to 6 weeks by taking advantage of the optical absorption contrast intrinsic to hemoglobin molecules in red blood cells. By combining with optical coherence tomography (OCT) based on optical scattering contrast, we also demonstrated the capability to simultaneously image and analyze the vasculature and the scaffold in the same mouse. The hybrid system containing OR-PAM and OCT offered a fine lateral resolution of \u223c5\u2009\u03bcm and a penetration depth of \u223c1\u2009mm into the scaffold/tissue construct. AR-PAM further extended the penetration depth up to \u223c3\u2009mm at a lateral resolution of \u223c45\u2009\u03bcm. By quantifying the 3D PAM data, we further examined the effect of pore size (200 vs. 80\u2009\u03bcm) of a scaffold on neovascularization. The data collected from PAM were consistent with those obtained from traditional invasive, labor-intensive histologic analyses.",
"doi": "10.1089/ten.tec.2012.0326",
"pmcid": "PMC3557912",
"issn": "1937-3384",
"publisher": "Mary Ann Liebert, Inc.",
"publication": "Tissue Engineering Part C: Methods",
"publication_date": "2013-03",
"series_number": "3",
"volume": "19",
"issue": "3",
"pages": "196-204"
},
{
"id": "authors:fj211-16449",
"collection": "authors",
"collection_id": "fj211-16449",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160805-154325044",
"type": "article",
"title": "Single-cell photoacoustic thermometry",
"author": [
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Ke",
"given_name": "Haixin",
"clpid": "Ke-Haixin"
},
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A novel photoacoustic thermometric method is presented for simultaneously imaging cells and sensing their temperature. With three-seconds-per-frame imaging speed, a temperature resolution of 0.2\u00b0C was achieved in a photo-thermal cell heating experiment. Compared to other approaches, the photoacoustic thermometric method has the advantage of not requiring custom-developed temperature-sensitive biosensors. This feature should facilitate the conversion of single-cell thermometry into a routine lab tool and make it accessible to a much broader biological research community.",
"doi": "10.1117/1.JBO.18.2.026003",
"pmcid": "PMC3556647",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2013-02",
"series_number": "2",
"volume": "18",
"issue": "2",
"pages": "Art. No. 026003"
},
{
"id": "authors:7mctf-7d164",
"collection": "authors",
"collection_id": "7mctf-7d164",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160803-111418126",
"type": "article",
"title": "Label-free photoacoustic microscopy of cytochromes",
"author": [
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Zhang",
"given_name": "Yu Shrike",
"clpid": "Zhang-Yu-Shrike"
},
{
"family_name": "Yao",
"given_name": "Da-Kang",
"clpid": "Yao-Da-Kang"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic microscopy (PAM) has achieved submicron lateral resolution in showing subcellular structures; however, relatively few endogenous subcellular contrasts have so far been imaged. Given that the hemeprotein, mostly cytochromes in general cells, is optically absorbing around the Soret peak (\u223c420\u2009\u2009nm), we implemented label-free PAM of cytochromes in cytoplasm for the first time. By measuring the photoacoustic spectra of the oxidized and reduced states of fibroblast lysate and fitting the difference spectrum with three types of cytochromes, we found that the three cytochromes account for more than half the optical absorption in the cell lysate at 420 nm wavelength. Fixed fibroblasts on slides were imaged by PAM at 422 and 250 nm wavelengths to reveal cytoplasms and nuclei, respectively, as confirmed by standard staining histology. PAM was also applied to label-free histology of mouse ear sections by showing cytoplasms and nuclei of various cells. PAM of cytochromes in cytoplasm is expected to be a high-throughput, label-free technique for studying live cell functions, which cannot be accomplished by conventional histology.",
"doi": "10.1117/1.JBO.18.2.020504",
"pmcid": "PMC3560837",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2013-02",
"series_number": "2",
"volume": "18",
"issue": "2",
"pages": "Art. No. 020504"
},
{
"id": "authors:96th8-nbm27",
"collection": "authors",
"collection_id": "96th8-nbm27",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160803-132546842",
"type": "article",
"title": "Micromachined silicon acoustic delay lines for ultrasound applications",
"author": [
{
"family_name": "Chang",
"given_name": "Cheng-Chung",
"clpid": "Chang-Cheng-Chung"
},
{
"family_name": "Cho",
"given_name": "Young",
"clpid": "Cho-Young"
},
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Zou",
"given_name": "Jun",
"orcid": "0000-0002-9543-6135",
"clpid": "Zou-Jun"
}
],
"abstract": "In this paper, we present the design, fabrication and testing of novel micromachined silicon-based acoustic delay lines. The acoustic properties of different silicon delay-line structures have been characterized. Based on the experiment results, two different acoustic delay line systems (parallel and serial) have been successfully demonstrated to create controlled time delays in multiple channels of ultrasound signals. The time-delayed ultrasound signals are received with a single-element ultrasound transducer in a time-serial manner. This unique capability could be used to merge multiple signal channels, thereby enabling new ultrasound receiver designs with potentially less complexity and lower cost.",
"doi": "10.1088/0960-1317/23/2/025006",
"pmcid": "PMC4627599",
"issn": "0960-1317",
"publisher": "IOP Publishing",
"publication": "Journal of Micromechanics and Microengineering",
"publication_date": "2013-02",
"series_number": "2",
"volume": "23",
"issue": "2",
"pages": "Art. No. 25006"
},
{
"id": "authors:qvqxq-r4493",
"collection": "authors",
"collection_id": "qvqxq-r4493",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180906-155129768",
"type": "article",
"title": "Continued Growth of JBO",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "JBO sustained its healthy growth in 2012. The number of manuscript submissions increased by 5% to 788. JBO's success is attributed to the contributions of the authors, reviewers, guest editors, and editorial board members.",
"doi": "10.1117/1.JBO.18.2.020101",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2013-02",
"series_number": "2",
"volume": "18",
"issue": "2",
"pages": "Art. No. 020101"
},
{
"id": "authors:3qa85-m8t34",
"collection": "authors",
"collection_id": "3qa85-m8t34",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160805-155123839",
"type": "article",
"title": "Transcranial Thermoacoustic Tomography: A Comparison of Two Imaging Algorithms",
"author": [
{
"family_name": "Liu",
"given_name": "Zijian",
"clpid": "Liu-Zijian"
},
{
"family_name": "Liu",
"given_name": "Lanbo",
"clpid": "Liu-Lanbo"
},
{
"family_name": "Xu",
"given_name": "Yuan",
"orcid": "0000-0001-9326-2197",
"clpid": "Xu-Yuan"
},
{
"family_name": "Wang",
"given_name": "Lihong Victory",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Thermoacoustic tomography (TAT) is a novel, non-invasive medical imaging technique but has encountered obstacles in imaging through the cranium. In this paper we present two methods for transcranial TAT: Kirchhoff migration (KM) and reverse-time migration (RTM). The two methods' imaging qualities are verified and compared based on both synthetic and experimental data. RTM proves to have better velocity variance and imaging quality, and little noise with spatial aliasing. RTM is a promising approach for achieving transcranial TAT in further studies.",
"doi": "10.1109/TMI.2012.2224667",
"issn": "0278-0062",
"publisher": "IEEE",
"publication": "IEEE Transactions on Medical Imaging",
"publication_date": "2013-02",
"series_number": "2",
"volume": "32",
"issue": "2",
"pages": "289-294"
},
{
"id": "authors:1g8wn-nd395",
"collection": "authors",
"collection_id": "1g8wn-nd395",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-140553425",
"type": "article",
"title": "Quantitative Analysis of the Fate of Gold Nanocages In Vitro and In Vivo after Uptake by U87-MG Tumor Cells",
"author": [
{
"family_name": "Cho",
"given_name": "Eun Chul",
"clpid": "Cho-Eun-Chul"
},
{
"family_name": "Zhang",
"given_name": "Yu",
"orcid": "0000-0001-8938-1927",
"clpid": "Zhang-Yu"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Moran",
"given_name": "Christine M.",
"clpid": "Moran-C-M"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "Not always equal: When a mother cell that contains Au nanocages divides, the nanoparticles are unequally distributed between the two daughter cells. This unequal distribution of nanoparticles as well as their clearance from the cells (see picture) is quantitatively analyzed both in\u2005vitro and in\u2005vivo using two-photon microscopy and photoacoustic microscopy, respectively.",
"doi": "10.1002/anie.201208096",
"pmcid": "PMC3730258",
"issn": "1433-7851",
"publisher": "Wiley",
"publication": "Angewandte Chemie International Edition",
"publication_date": "2013-01-21",
"series_number": "4",
"volume": "52",
"issue": "4",
"pages": "1152-1155"
},
{
"id": "authors:9ndmv-4wv52",
"collection": "authors",
"collection_id": "9ndmv-4wv52",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160803-105422756",
"type": "article",
"title": "Integrated optical- and acoustic-resolution photoacoustic microscopy based on an optical fiber bundle",
"author": [
{
"family_name": "Xing",
"given_name": "Wenxin",
"clpid": "Xing-Wenxin"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic microscopy (PAM), whose spatial resolution and maximum imaging depth are both scalable, has made great progress in recent years. However, each PAM system currently achieves only one resolution with an associated maximum imaging depth. Here, we present an integrated optical-resolution (OR) and acoustic-resolution (AR) PAM system implemented by delivering light via an optical fiber bundle. A single fiber core is used to deliver light for OR illumination in order to achieve a small spot size and hence high lateral resolution, whereas all the fiber cores are used to deliver more energy for AR illumination. Most other components are shared by the OR and AR imaging. The lateral resolution can be seamlessly switched between 2.2 and 40 \u03bcm as the maximum imaging depth is switched between 1.3 and 3.0 mm. The system enables automatically coregistered higher-resolution OR and deeper AR photoacoustic imaging.",
"doi": "10.1364/OL.38.000052",
"pmcid": "PMC4011141",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2013-01-01",
"series_number": "1",
"volume": "38",
"issue": "1",
"pages": "52-54"
},
{
"id": "authors:my68x-fw918",
"collection": "authors",
"collection_id": "my68x-fw918",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160711-151157171",
"type": "article",
"title": "Noninvasive photoacoustic computed tomography of mouse brain metabolism in vivo",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Nasiriavanaki",
"given_name": "Mohammadreza",
"clpid": "Nasiriavanaki-M"
},
{
"family_name": "Tsytsarev",
"given_name": "Vassiliy",
"clpid": "Tsytsarev-V"
},
{
"family_name": "Demchenko",
"given_name": "Alexei V.",
"clpid": "Demchenko-A-V"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have demonstrated the feasibility of imaging mouse brain metabolism using photoacoustic computed tomography (PACT), a fast, noninvasive and functional imaging modality with optical contrast and acoustic resolution. Brain responses to forepaw stimulations were imaged transdermally and transcranially. 2-NBDG, which diffuses well across the blood\u2013brain-barrier, provided exogenous contrast for photoacoustic imaging of glucose response. Concurrently, hemoglobin provided endogenous contrast for photoacoustic imaging of hemodynamic response. Glucose and hemodynamic responses were quantitatively decoupled by using two-wavelength measurements. We found that glucose uptake and blood perfusion around the somatosensory region of the contralateral hemisphere were both increased by stimulations, indicating elevated neuron activity. While the glucose response area was more homogenous and confined within the somatosensory region, the hemodynamic response area had a clear vascular pattern and spread wider than the somatosensory region. Our results demonstrate that 2-NBDG-enhanced PACT is a promising tool for noninvasive studies of brain metabolism.",
"doi": "10.1016/j.neuroimage.2012.08.054",
"pmcid": "PMC3508393",
"issn": "1053-8119",
"publisher": "Elsevier",
"publication": "NeuroImage",
"publication_date": "2013-01-01",
"volume": "64",
"pages": "257-266"
},
{
"id": "authors:tr0d1-8vh87",
"collection": "authors",
"collection_id": "tr0d1-8vh87",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160614-091401767",
"type": "article",
"title": "Photoacoustic microscopy using F\u00f6rster resonance energy transfer",
"author": [
{
"family_name": "Wang",
"given_name": "Yu",
"orcid": "0000-0003-3589-9274",
"clpid": "Wang-Yu"
},
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "High-resolution images in deep tissue are obtained using photoacoustic images of F\u00f6rster resonance energy transfer, overcoming the problem of light-scattering effects in some imaging techniques.",
"doi": "10.1117/2.1201211.004595",
"issn": "1818-2259",
"publisher": "SPIE",
"publication": "SPIE Newsroom",
"publication_date": "2012-12-12",
"pages": "Art. NO. 4595"
},
{
"id": "authors:t7hew-61363",
"collection": "authors",
"collection_id": "t7hew-61363",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160809-152945073",
"type": "article",
"title": "Effects of light scattering on optical-resolution photoacoustic microscopy",
"author": [
{
"family_name": "Liu",
"given_name": "Yan",
"orcid": "0000-0002-5837-4908",
"clpid": "Liu-Yan"
},
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The imaging depth of ballistic optical imaging technologies is limited by light scattering. To study the effects of scattering on optical-resolution photoacoustic microscopy (OR-PAM), the signals were divided into target and background signals. A method to simulate the point spread function (PSF) of the PAM system considering both optical illumination and acoustic detection was proposed, then the PSF was used to calculate the contribution of each class of signal at different depths of the focal plane (z_f). How image contrast is degraded when there is a uniformly absorbing background as well as when there are small targets densely packed in the acoustic resolution cell were studied. By using the hyperboloid-focusing-based Monte Carlo method, optical focusing into a scattering medium was simulated. It was found that the lateral resolution provided by optical focusing is degraded by only 14% when z_f=1.1 transport mean free path (l'_t), compared with the case of no scattering. When z_f =1.7\u2009l\u2032_t, the fluence at 50 \u03bcm radial distance away from the focal point is 93% of that at the focal point, which shows optical focusing is very weak at this depth. The method to simulate the PSF of PAM can be used in the future to optimize parameters so as to improve the system performance.",
"doi": "10.1117/1.JBO.17.12.126014",
"pmcid": "PMC3518877",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-12",
"series_number": "12",
"volume": "17",
"issue": "12",
"pages": "Art. No. 126014"
},
{
"id": "authors:42mc0-1w093",
"collection": "authors",
"collection_id": "42mc0-1w093",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160812-144929739",
"type": "article",
"title": "Photoacoustic microscopy of bilirubin in tissue phantoms",
"author": [
{
"family_name": "Zhou",
"given_name": "Yong",
"clpid": "Zhou-Yong"
},
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Yao",
"given_name": "Da-Kang",
"clpid": "Yao-Da-Kang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Determining both bilirubin's concentration and its spatial distribution are important in disease diagnosis. Here, for the first time, we applied quantitative multiwavelength photoacoustic microscopy (PAM) to detect bilirubin concentration and distribution simultaneously. By measuring tissue-mimicking phantoms with different bilirubin concentrations, we showed that the root-mean-square error of prediction has reached 0.52 and 0.83\u2009\u2009mg/dL for pure bilirubin and for blood-mixed bilirubin detection (with 100% oxygen saturation), respectively. We further demonstrated the capability of the PAM system to image bilirubin distribution both with and without blood. Finally, by underlaying bilirubin phantoms with mouse skins, we showed that bilirubin can be imaged with consistent accuracy down to >400\u2009\u2009\u03bcm in depth. Our results show that PAM has potential for noninvasive bilirubin monitoring in vivo, as well as for further clinical applications.",
"doi": "10.1117/1.JBO.17.12.126019",
"pmcid": "PMC3521055",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-12",
"series_number": "12",
"volume": "17",
"issue": "12",
"pages": "Art. No. 126019"
},
{
"id": "authors:x9xff-b6945",
"collection": "authors",
"collection_id": "x9xff-b6945",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160810-083121242",
"type": "article",
"title": "In vivo optical-resolution photoacoustic computed tomography with compressed sensing",
"author": [
{
"family_name": "Meng",
"given_name": "Jing",
"orcid": "0000-0002-9069-8988",
"clpid": "Meng-Jing"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Liang",
"given_name": "Dong",
"clpid": "Liang-Dong"
},
{
"family_name": "Song",
"given_name": "Liang",
"clpid": "Song-Liang"
}
],
"abstract": "Optical-resolution photoacoustic microscopy is becoming a powerful research tool for studying microcirculation in vivo. Moreover, ultrasonic-array-based optical-resolution photoacoustic computed tomography (OR-PACT), providing comparable resolution at an improved speed, has opened up new opportunities for studying microvascular dynamics. In this Letter, we have developed a compressed sensing with partially known support (CS-PKS) photoacoustic reconstruction strategy for OR-PACT. Compared with conventional backprojection reconstruction, the CS-PKS strategy was shown to produce high-quality in vivo OR-PACT images with threefold less measurement data, which can be leveraged to improve the data acquisition speed and costs of OR-PACT systems.",
"doi": "10.1364/OL.37.004573",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2012-11-15",
"series_number": "22",
"volume": "37",
"issue": "22",
"pages": "4573-4575"
},
{
"id": "authors:gjkdt-2k405",
"collection": "authors",
"collection_id": "gjkdt-2k405",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180918-110120453",
"type": "article",
"title": "In vivo photoacoustic microscopy with 7.6-\u00b5m axial resolution using a commercial 125-MHz ultrasonic transducer",
"author": [
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic microscopy has achieved submicron lateral resolution, but its axial resolution is much lower. Here an axial resolution of 7.6 \u03bcm, the highest axial resolution validated by experimental data, has been achieved by using a commercial 125 MHz ultrasonic transducer for signal detection followed by the Wiener deconvolution for signal processing. Limited by the working distance, the high-frequency ultrasonic transducer can penetrate 1.2 mm into biological tissue from the ultrasound detection side. At this depth, the signal-to-noise ratio decreases by 11 dB, and the axial resolution degrades by 36%. The new system was demonstrated in imaging melanoma cells ex vivo and mouse ears in vivo.",
"doi": "10.1117/1.JBO.17.11.116016",
"pmcid": "PMC3487171",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-11",
"series_number": "11",
"volume": "17",
"issue": "11",
"pages": "Art. No. 116016"
},
{
"id": "authors:kmne2-n1758",
"collection": "authors",
"collection_id": "kmne2-n1758",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160812-153536809",
"type": "article",
"title": "Photoacoustic tomography through a whole adult human skull with a photon recycler",
"author": [
{
"family_name": "Nie",
"given_name": "Liming",
"clpid": "Nie-Liming"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) of the human brain is challenging due to the fact that the skull strongly absorbs and scatters light, and attenuates and distorts ultrasound as well. For the first time, we demonstrated the feasibility of PAT through a whole adult human skull. A photon recycler (PR) was built to increase light transmittance through the skull. Both a graphite target and a canine brain were imaged through the skull. Use of the PR was found to improve the photoacoustic signal-to-noise ratio by a factor of 2.4. In addition, subtraction of photoacoustic signals that arise from light absorption within the skull significantly improved the contrast of the target. Our results indicate that PAT can potentially be applied to in vivo human brain imaging.",
"doi": "10.1117/1.JBO.17.11.110506",
"pmcid": "PMC3487537",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-11",
"series_number": "11",
"volume": "17",
"issue": "11",
"pages": "Art. No. 110506"
},
{
"id": "authors:zk4gn-55r09",
"collection": "authors",
"collection_id": "zk4gn-55r09",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160812-132252536",
"type": "article",
"title": "Parallel acoustic delay lines for photoacoustic tomography",
"author": [
{
"family_name": "Yapici",
"given_name": "Murat Kaya",
"clpid": "Yapici-M-K"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Chang",
"given_name": "Cheng-Chung",
"clpid": "Chang-Cheng-Chung"
},
{
"family_name": "Jeon",
"given_name": "Mansik",
"clpid": "Jeon-Mansik"
},
{
"family_name": "Guo",
"given_name": "Zijian",
"clpid": "Guo-Zijian"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Zou",
"given_name": "Jun",
"orcid": "0000-0002-9543-6135",
"clpid": "Zou-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Achieving real-time photoacoustic (PA) tomography typically requires multi-element ultrasound transducer arrays and their associated multiple data acquisition (DAQ) electronics to receive PA waves simultaneously. We report the first demonstration of a photoacoustic tomography (PAT) system using optical fiber-based parallel acoustic delay lines (PADLs). By employing PADLs to introduce specific time delays, the PA signals (on the order of a few micro seconds) can be forced to arrive at the ultrasonic transducers at different times. As a result, time-delayed PA signals in multiple channels can be ultimately received and processed in a serial manner with a single-element transducer, followed by single-channel DAQ electronics. Our results show that an optically absorbing target in an optically scattering medium can be photoacoustically imaged using the newly developed PADL-based PAT system. Potentially, this approach could be adopted to significantly reduce the complexity and cost of ultrasonic array receiver systems.",
"doi": "10.1117/1.JBO.17.11.116019",
"pmcid": "PMC3491084",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-11",
"series_number": "11",
"volume": "17",
"issue": "11",
"pages": "Art. No. 116019"
},
{
"id": "authors:c0s1f-9cd48",
"collection": "authors",
"collection_id": "c0s1f-9cd48",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160810-085647024",
"type": "article",
"title": "In vivophotoacoustic microscopy with 7.6-\u00b5m axial resolution using a commercial 125-MHz ultrasonic transducer",
"author": [
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic microscopy has achieved submicron lateral resolution, but its axial resolution is much lower. Here an axial resolution of 7.6 \u03bcm, the highest axial resolution validated by experimental data, has been achieved by using a commercial 125 MHz ultrasonic transducer for signal detection followed by the Wiener deconvolution for signal processing. Limited by the working distance, the high-frequency ultrasonic transducer can penetrate 1.2 mm into biological tissue from the ultrasound detection side. At this depth, the signal-to-noise ratio decreases by 11 dB, and the axial resolution degrades by 36%. The new system was demonstrated in imaging melanoma cells ex vivo and mouse ears in vivo.",
"doi": "10.1117/1.JBO.17.11.116016",
"pmcid": "PMC3487171",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-11",
"series_number": "11",
"volume": "17",
"issue": "11",
"pages": "Art. No. 116016"
},
{
"id": "authors:vp240-v3c67",
"collection": "authors",
"collection_id": "vp240-v3c67",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160809-084840381",
"type": "article",
"title": "A 25-mm diameter probe for photoacoustic and ultrasonic endoscopy",
"author": [
{
"family_name": "Yang",
"given_name": "Joon-Mo",
"clpid": "Yang-Joon-Mo"
},
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "Favazza",
"given_name": "Christopher",
"clpid": "Favazza-C-P"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Li",
"given_name": "Chiye",
"clpid": "Li-Chiye"
},
{
"family_name": "Hu",
"given_name": "Zhilin",
"clpid": "Hu-Zhilin"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have created a 2.5-mm outer diameter integrated photo-acoustic and ultrasonic mini-probe which can be inserted into a standard video endoscope's instrument channel. A small-diameter focused ultrasonic transducer made of PMN-PT provides adequate signal sensitivity, and enables miniaturization of the probe. Additionally, this new endoscopic probe utilizes the same scanning mirror and micromotor-based built-in actuator described in our previous reports; however, the length of the rigid distal section of the new probe has been further reduced to ~35 mm. This paper describes the technical details of the mini-probe and presents experimental results that both quantify the imaging performance and demonstrate its in vivo imaging capability, which suggests that it could work as a mini-probe for certain clinical applications.",
"doi": "10.1364/OE.20.023944",
"pmcid": "PMC3601641",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "2012-10-08",
"series_number": "21",
"volume": "20",
"issue": "21",
"pages": "23944-23953"
},
{
"id": "authors:cn76e-hkz60",
"collection": "authors",
"collection_id": "cn76e-hkz60",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160817-073630833",
"type": "article",
"title": "Video-rate functional photoacoustic microscopy at depths",
"author": [
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Xing",
"given_name": "Wenxin",
"clpid": "Xing-Wenxin"
},
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We report the development of functional photoacoustic microscopy capable of video-rate high-resolution in vivo imaging in deep tissue. A lightweight photoacoustic probe is made of a single-element broadband ultrasound transducer, a compact photoacoustic beam combiner, and a bright-field light delivery system. Focused broadband ultrasound detection provides a 44-\u03bcm lateral resolution and a 28-\u03bcm axial resolution based on the envelope (a 15-\u03bcm axial resolution based on the raw RF signal). Due to the efficient bright-field light delivery, the system can image as deep as 4.8 mm in vivo using low excitation pulse energy (28 \u03bcJ per pulse, 0.35\u2009\u2009mJ/cm^2 on the skin surface). The photoacoustic probe is mounted on a fast-scanning voice-coil scanner to acquire 40 two-dimensional (2-D) B-scan images per second over a 9-mm range. High-resolution anatomical imaging is demonstrated in the mouse ear and brain. Via fast dual-wavelength switching, oxygen dynamics of mouse cardio-vasculature is imaged in realtime as well.",
"doi": "10.1117/1.JBO.17.10.106007",
"pmcid": "PMC3461058",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-10",
"series_number": "10",
"volume": "17",
"issue": "10",
"pages": "Art. No. 1060071"
},
{
"id": "authors:y35ph-hhd22",
"collection": "authors",
"collection_id": "y35ph-hhd22",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180918-111533221",
"type": "article",
"title": "New Open Access Option for JBO",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The Journal of Biomedical Optics (JBO) has a new benefit for authors who support the journal through payment of voluntary page charges. Starting in January 2013, research articles for which such page charges are paid will gain open access immediately at publication. All review and tutorial articles will continue to enjoy unconditional open access. Open access will enable anyone to read your article online at no charge and should lead to more awareness of your research and may result in more citations. In addition, authors will retain copyright for open access articles through a Creative Commons attribution license (CC-BY \"gold open access\"; see http://creativecommons.org/licenses/by/3.0/). This is the type of license that many employers and research-funding agencies prefer or require.",
"doi": "10.1117/1.JBO.17.9.090101",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-09",
"series_number": "9",
"volume": "17",
"issue": "9",
"pages": "Art. No. 090101"
},
{
"id": "authors:q7mqa-3yd12",
"collection": "authors",
"collection_id": "q7mqa-3yd12",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160812-161303650",
"type": "article",
"title": "Rapid Synthesis of Near Infrared Polymeric Micelles for Real-Time Sentinel Lymph Node Imaging",
"author": [
{
"family_name": "Pan",
"given_name": "Dipanjan",
"clpid": "Pan-Dipanjan"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Kim",
"given_name": "Benjamin",
"clpid": "Kim-Benjamin"
},
{
"family_name": "Stacy",
"given_name": "Allen J.",
"clpid": "Stacy-A-J"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Lanza",
"given_name": "Gregory M.",
"clpid": "Lanza-G-M"
}
],
"abstract": "In this manuscript a synthetic methodology for developing sub 20 nm sized polymeric micellar nanoparticles designed for extravascular imaging and therapy is revealed. A simple, one-pot method is followed, which involves a rapid co-self-assembly of an amphiphilic diblock copolymer (PS-b-PAA) and polyoxyethylene (80) sorbitan monooleate in water. Sorbitan monooleate imparts stability to the micelles and helps to drive down the particle size below 20 nm. The particles are incorporated with a water soluble dye ADS832WS, which absorbs in the near infrared range (\u03bb_(ex) = 832 nm) for sensitive detection with optical and photoacoustic imaging techniques. A candidate lipophilic anti-angiogenic therapeutic agent fumagillin was also incorporated with high entrapment (>95%) efficiency. The effectiveness of this theranostic platform for real-time, high-resolution intraoperative photoacoustic imaging for facilitating direct assessment of the sentinel lymph nodes (SLN) in breast cancer staging is demonstrated. The technique offers huge potential providing faster resection of SLN and may minimize complications caused by axillary exploration due to mismarking with dyes or low-resolution imaging techniques. Finally, the biodistribution and organ accumulation of the intravenously and intradermally injected particles are studied in a rodent model by optical imaging. Data suggest that intraveneously injected NIR-polymeric nanoparticles follow a typical bio-distribution clearance path through the reticuloendothelial (RES) system. For the intradermally injected particles, a slower mechanism of clearance is noticed.",
"doi": "10.1002/adhm.201200087",
"pmcid": "PMC5041307",
"issn": "2192-2640",
"publisher": "Wiley",
"publication": "Advanced Healthcare Materials",
"publication_date": "2012-09",
"series_number": "5",
"volume": "1",
"issue": "5",
"pages": "582-589"
},
{
"id": "authors:175mc-hx620",
"collection": "authors",
"collection_id": "175mc-hx620",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160810-073715375",
"type": "article",
"title": "F\u00f6rster resonance energy transfer photoacoustic microscopy",
"author": [
{
"family_name": "Wang",
"given_name": "Yu",
"orcid": "0000-0003-3589-9274",
"clpid": "Wang-Yu"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "F\u00f6rster, or fluorescence, resonance energy transfer (FRET) provides fluorescence signals sensitive to intra- and inter-molecular distances in the 1 to 10 nm range. Widely applied in the fluorescence imaging environment, FRET enables visualization of physicochemical processes in molecular interactions and conformations. In this paper, we report photoacoustic imaging of FRET, based on nonradiative decay that produces heat and subsequent acoustic waves. Estimates of the energy transfer efficiency by photoacoustic microscopy were compared to those obtained by fluorescence confocal microscopy. The experimental results in tissue phantoms show that photoacoustic microscopy is capable of FRET imaging with an enhanced penetration depth. Through its ability to three-dimensionally image tissue with scalable resolution, photoacoustic microscopy could be a beneficial biomedical tool to broaden the in vivo application of FRET.",
"doi": "10.1117/1.JBO.17.8.086007",
"pmcid": "PMC3414237",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-08",
"series_number": "8",
"volume": "17",
"issue": "8",
"pages": "Art. No. 086007"
},
{
"id": "authors:0h5eq-7sa42",
"collection": "authors",
"collection_id": "0h5eq-7sa42",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160817-084003471",
"type": "article",
"title": "Wide-field fast-scanning photoacoustic microscopy based on a water-immersible MEMS scanning mirror",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Huang",
"given_name": "Chih-Hsien",
"clpid": "Huang-Chih-Hsien"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Yang",
"given_name": "Joon-Mo",
"clpid": "Yang-Joon-Mo"
},
{
"family_name": "Gao",
"given_name": "Liang",
"clpid": "Gao-Liang"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Zou",
"given_name": "Jun",
"orcid": "0000-0002-9543-6135",
"clpid": "Zou-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "By offering images with high spatial resolution and unique optical absorption contrast, optical-resolution photoacoustic microscopy (OR-PAM) has gained increasing attention in biomedical research. Recent developments in OR-PAM have improved its imaging speed, but have to sacrifice either the detection sensitivity or field of view or both. We have developed a wide-field fast-scanning OR-PAM by using a water-immersible microelectromechanical systems (MEMS) scanning mirror (MEMS-OR-PAM). In MEMS-OR-PAM, the optical and acoustic beams are confocally configured and simultaneously steered, which ensures the uniform detection sensitivity. A B-scan imaging speed as high as 400 Hz can be achieved over a 3 mm scanning range. Using the system, we imaged the flow dynamics of both red blood cells and carbon particles in a mouse ear in vivo. Presented results show that MEMS-OR-PAM could be a powerful tool for studying highly dynamic and time-sensitive biological phenomena.",
"doi": "10.1117/1.JBO.17.8.080505",
"pmcid": "PMC3418511",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-08",
"series_number": "8",
"volume": "17",
"issue": "8",
"pages": "Art. No. 080505"
},
{
"id": "authors:vvnzk-s2k43",
"collection": "authors",
"collection_id": "vvnzk-s2k43",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160810-103931840",
"type": "article",
"title": "Multi-Scale Molecular Photoacoustic Tomography of Gene Expression",
"author": [
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Li",
"given_name": "Li",
"clpid": "Li-Li"
},
{
"family_name": "Krumholz",
"given_name": "Arie",
"clpid": "Krumholz-A"
},
{
"family_name": "Guo",
"given_name": "Zijian",
"clpid": "Guo-Zijian"
},
{
"family_name": "Erpelding",
"given_name": "Todd N.",
"clpid": "Erpelding-T-N"
},
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Zhang",
"given_name": "Yu",
"orcid": "0000-0001-8938-1927",
"clpid": "Zhang-Yu"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) is a molecular imaging technology. Unlike conventional reporter gene imaging, which is usually based on fluorescence, photoacoustic reporter gene imaging relies only on optical absorption. This work demonstrates several key merits of PAT using lacZ, one of the most widely used reporter genes in biology. We show that the expression of lacZ can be imaged by PAT as deep as 5.0 cm in biological tissue, with resolutions of \u223c1.0 mm and \u223c0.4 mm in the lateral and axial directions, respectively. We further demonstrate non-invasive, simultaneous imaging of a lacZ-expressing tumor and its surrounding microvasculature in vivo by dual-wavelength acoustic-resolution photoacoustic microscopy (AR-PAM), with a lateral resolution of 45 \u00b5m and an axial resolution of 15 \u00b5m. Finally, using optical-resolution photoacoustic microscopy (OR-PAM), we show intra-cellular localization of lacZ expression, with a lateral resolution of a fraction of a micron. These results suggest that PAT is a complementary tool to conventional optical fluorescence imaging of reporter genes for linking biological studies from the microscopic to the macroscopic scales.",
"doi": "10.1371/journal.pone.0043999",
"pmcid": "PMC3428330",
"issn": "1932-6203",
"publisher": "Public Library of Science",
"publication": "PLoS ONE",
"publication_date": "2012-08",
"series_number": "8",
"volume": "7",
"issue": "8",
"pages": "Art. No. e43999"
},
{
"id": "authors:wekfb-nz389",
"collection": "authors",
"collection_id": "wekfb-nz389",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-153332844",
"type": "article",
"title": "In vivo Photoacoustic Tomography of Total Blood Flow and Potential Imaging of Cancer Angiogenesis and Hypermetabolism",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Blood flow is a key parameter in studying cancer angiogenesis and hypermetabolism. Current photoacoustic blood flow estimation methods focus on either the axial or transverse component of the flow vector. However, the Doppler angle (beam-to-flow angle) is needed to calculate the total flow speed, and it cannot always be estimated accurately in practice, especially when the system's axial and lateral resolutions are different. To overcome this problem, we propose a method to compute the total flow speed and Doppler angle by combining the axial and transverse flow measurements. The method has been verified by flowing bovine blood in a plastic tube at various speeds and Doppler angles. The error was experimentally determined to be less than 0.3 mm/s for total flow speed, and less than 15\u00b0 for the Doppler angle. In addition, the method was tested in vivo on a mouse ear. We believe that the proposed method has the potential to be used for cancer angiogenesis and hypermetabolism imaging.",
"doi": "10.7785/tcrt.2012.500278",
"pmcid": "PMC3376701",
"issn": "1533-0346",
"publisher": "SAGE Publications",
"publication": "Technology in Cancer Research and Treatment",
"publication_date": "2012-08",
"series_number": "4",
"volume": "11",
"issue": "4",
"pages": "301-307"
},
{
"id": "authors:nfv17-9j910",
"collection": "authors",
"collection_id": "nfv17-9j910",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160809-154049931",
"type": "article",
"title": "Energy enhancement in time-reversed ultrasonically encoded optical focusing using a photorefractive polymer",
"author": [
{
"family_name": "Suzuki",
"given_name": "Yuta",
"clpid": "Suzuki-Yuta"
},
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Lai",
"given_name": "Puxiang",
"clpid": "Lai-Puxiang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Time-reversed ultrasonically encoded (TRUE) optical focusing achieves light focusing into scattering media beyond one transport mean free path, which is desirable in biomedical optics. However, the focused optical energy needs to be increased for broad applications. Here, we report the use of a photorefractive polymer (PRP) as the phase conjugate mirror in TRUE optical focusing. The PRP boosted the focused optical energy by \u223c40 times in comparison to the previously used photorefractive Bi_(12)SiO_(20) crystal. As a result, we successfully imaged absorbing objects embedded in the middle plane of a tissue-mimicking phantom having an optical thickness of 120 scattering mean free paths.",
"doi": "10.1117/1.JBO.17.8.080507",
"pmcid": "PMC3418504",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-08",
"series_number": "8",
"volume": "17",
"issue": "8",
"pages": "Art. No. 080507"
},
{
"id": "authors:xsq90-33498",
"collection": "authors",
"collection_id": "xsq90-33498",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160809-103335168",
"type": "article",
"title": "Compressed-sensing photoacoustic computed tomography in vivo with partially known support",
"author": [
{
"family_name": "Meng",
"given_name": "Jing",
"orcid": "0000-0002-9069-8988",
"clpid": "Meng-Jing"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Ying",
"given_name": "Leslie",
"clpid": "Ying-Leslie"
},
{
"family_name": "Liang",
"given_name": "Dong",
"clpid": "Liang-Dong"
},
{
"family_name": "Song",
"given_name": "Liang",
"clpid": "Song-Liang"
}
],
"abstract": "Compressed sensing (CS) can recover sparse signals from under-sampled measurements. In this work, we have developed an advanced CS framework for photoacoustic computed tomography (PACT). During the reconstruction, a small part of the nonzero signals' locations in the transformed sparse domain is used as partially known support (PKS). PACT reconstructions have been performed with under-sampled in vivo image data of human hands and a rat. Compared to PACT with basic CS, PACT with CS-PKS can recover signals using fewer ultrasonic transducer elements and can improve convergence speed, which may ultimately enable high-speed, low-cost PACT for various biomedical applications.",
"doi": "10.1364/OE.20.016510",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "2012-07-16",
"series_number": "15",
"volume": "20",
"issue": "15",
"pages": "16510-16523"
},
{
"id": "authors:r8txy-ybn29",
"collection": "authors",
"collection_id": "r8txy-ybn29",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160615-090223510",
"type": "article",
"title": "Simultaneous functional photoacoustic and ultrasonic endoscopy of internal organs in vivo",
"author": [
{
"family_name": "Yang",
"given_name": "Joon-Mo",
"clpid": "Yang-Joon-Mo"
},
{
"family_name": "Favazza",
"given_name": "Christopher",
"clpid": "Favazza-C"
},
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "At present, clinicians routinely apply ultrasound endoscopy in a variety of interventional procedures that provide treatment solutions for diseased organs. Ultrasound endoscopy not only produces high-resolution images, but also is safe for clinical use and broadly applicable. However, for soft tissue imaging, its mechanical wave\u2013based image contrast fundamentally limits its ability to provide physiologically specific functional information. By contrast, photoacoustic endoscopy possesses a unique combination of functional optical contrast and high spatial resolution at clinically relevant depths, ideal for imaging soft tissues. With these attributes, photoacoustic endoscopy can overcome the current limitations of ultrasound endoscopy. Moreover, the benefits of photoacoustic imaging do not come at the expense of existing ultrasound functions; photoacoustic endoscopy systems are inherently compatible with ultrasound imaging, thereby enabling multimodality imaging with complementary contrast. Here we present simultaneous photoacoustic and ultrasonic dual-mode endoscopy and show its ability to image internal organs in vivo, thus illustrating its potential clinical application.",
"doi": "10.1038/nm.2823",
"pmcid": "PMC3885361",
"issn": "1078-8956",
"publisher": "Nature Publishing Group",
"publication": "Nature Medicine",
"publication_date": "2012-07-15",
"series_number": "8",
"volume": "18",
"issue": "8",
"pages": "1297-1302"
},
{
"id": "authors:dtqpf-6ta51",
"collection": "authors",
"collection_id": "dtqpf-6ta51",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160812-145808795",
"type": "article",
"title": "Photoacoustic microscopy of blood pulse wave",
"author": [
{
"family_name": "Yeh",
"given_name": "Chenghung",
"clpid": "Yeh-Chenghung"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Blood pulse wave velocity (PWV) is an important physiological parameter that characterizes vascular stiffness. In this letter, we present electrocardiogram-synchronized, photoacoustic microscopy for noninvasive quantification of the PWV in the peripheral vessels of living mice. Interestingly, blood pulse wave-induced fluctuations in blood flow speed were clearly observed in arteries and arterioles, but not in veins or venules. Simultaneously recorded electrocardiograms served as references to measure the travel time of the pulse wave between two cross sections of a chosen vessel and vessel segmentation analysis enabled accurate quantification of the travel distance. PWVs were quantified in ten vessel segments from two mice. Statistical analysis shows a linear correlation between the PWV and the vessel diameter which agrees with known physiology.",
"doi": "10.1117/1.JBO.17.7.070504",
"pmcid": "PMC3384983",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-07",
"series_number": "7",
"volume": "17",
"issue": "7",
"pages": "Art. No. 0705041"
},
{
"id": "authors:6a83z-zh528",
"collection": "authors",
"collection_id": "6a83z-zh528",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160816-160335773",
"type": "article",
"title": "Tumor glucose metabolism imaged in vivo in small animals with whole-body photoacoustic computed tomography",
"author": [
{
"family_name": "Chatni",
"given_name": "Muhammad Rameez",
"clpid": "Chatni-M-R"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Sohn",
"given_name": "Rebecca",
"clpid": "Sohn-R"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Guo",
"given_name": "Zijian",
"clpid": "Guo-Zijian"
},
{
"family_name": "Zhang",
"given_name": "Yu",
"orcid": "0000-0001-8938-1927",
"clpid": "Zhang-Yu"
},
{
"family_name": "Wang",
"given_name": "Kun",
"clpid": "Wang-Kun"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
},
{
"family_name": "Anastasio",
"given_name": "Mark",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
},
{
"family_name": "Arbeit",
"given_name": "Jeffrey",
"clpid": "Arbeit-J"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "With the increasing use of small animals for human disease studies, small-animal whole-body molecular imaging plays an important role in biomedical research. Currently, none of the existing imaging modalities can provide both anatomical and glucose molecular information, leading to higher costs of building dual-modality systems. Even with image co-registration, the spatial resolution of the molecular imaging modality is not improved. Utilizing a ring-shaped confocal photoacoustic computed tomography system, we demonstrate, for the first time, that both anatomy and glucose uptake can be imaged in a single modality. Anatomy was imaged with the endogenous hemoglobin contrast, and glucose metabolism was imaged with a near-infrared dye-labeled 2-deoxyglucose.",
"doi": "10.1117/1.JBO.17.7.076012",
"pmcid": "PMC3390466",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-07",
"series_number": "7",
"volume": "17",
"issue": "7",
"pages": "Art. No. 076012"
},
{
"id": "authors:0eewm-2g810",
"collection": "authors",
"collection_id": "0eewm-2g810",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160809-160104121",
"type": "article",
"title": "In Vivo Diagnosis of Melanoma and Nonmelanoma Skin Cancer Using Oblique Incidence Diffuse Reflectance Spectrometry",
"author": [
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Zou",
"given_name": "Jun",
"orcid": "0000-0002-9543-6135",
"clpid": "Zou-Jun"
},
{
"family_name": "Duvic",
"given_name": "Madeleine",
"clpid": "Duvic-M"
},
{
"family_name": "Cho-Vega",
"given_name": "Jeong Hee",
"clpid": "Cho-Vega-Jeong-Hee"
},
{
"family_name": "Prieto",
"given_name": "Victor G.",
"clpid": "Prieto-V-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Early detection and treatment of skin cancer can significantly improve patient outcome. However, present standards for diagnosis require biopsy and histopathologic examinations that are relatively invasive, expensive, and difficult for patients with many early-stage lesions. Here, we show an oblique incidence diffuse reflectance spectroscopic (OIDRS) system that can be used for rapid skin cancer detection in vivo. This system was tested under clinical conditions by obtaining spectra from pigmented and nonpigmented skin lesions, including melanomas, differently staged dysplastic nevi, and common nevi that were validated by standard pathohistologic criteria. For diagnosis of pigmented melanoma, the data obtained achieved 90% sensitivity and specificity for a blinded test set. In a second analysis, we showed that this spectroscopy system can also differentiate nonpigmented basal cell or squamous cell carcinomas from noncancerous skin abnormalities, such as actinic keratoses and seborrheic keratoses, achieving 92% sensitivity and specificity. Taken together, our findings establish how OIDRS can be used to more rapidly and easily diagnose skin cancer in an accurate and automated manner in the clinic.",
"doi": "10.1158/0008-5472.CAN-11-4027",
"pmcid": "PMC3367032",
"issn": "0008-5472",
"publisher": "American Association for Cancer Research",
"publication": "Cancer Research",
"publication_date": "2012-06-01",
"series_number": "11",
"volume": "72",
"issue": "11",
"pages": "2738-2745"
},
{
"id": "authors:jqvr6-70q79",
"collection": "authors",
"collection_id": "jqvr6-70q79",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160817-073054013",
"type": "article",
"title": "Ultrasound-modulated optical tomography at new depth",
"author": [
{
"family_name": "Lai",
"given_name": "Puxiang",
"clpid": "Lai-Puxiang"
},
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Ultrasound-modulated optical tomography (UOT) has the potential to reveal optical contrast deep inside soft biological tissues at an ultrasonically determined spatial resolution. The optical imaging depth reported so far has, however, been limited, which prevents this technique from broader applications. Our latest experimental exploration has pushed UOT to an unprecedented imaging depth. We developed and optimized a UOT system employing a photorefractive crystal-based interferometer. A large aperture optical fiber bundle was used to enhance the efficiencies for diffuse light collection and photorefractive two-wave-mixing. Within the safety limits for both laser illumination and ultrasound modulation, the system has attained the ability to image through a tissue-mimicking phantom of 9.4 cm in thickness, which has never been reached previously by UOT.",
"doi": "10.1117/1.JBO.17.6.066006",
"pmcid": "PMC3381033",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-06",
"series_number": "6",
"volume": "17",
"issue": "6",
"pages": "Art. No. 066006"
},
{
"id": "authors:3tnam-63881",
"collection": "authors",
"collection_id": "3tnam-63881",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160812-115240913",
"type": "article",
"title": "Numerical investigation of the effects of shear waves in transcranial photoacoustic tomography with a planar geometry",
"author": [
{
"family_name": "Schoonover",
"given_name": "Robert W.",
"clpid": "Schoonover-R-W"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
}
],
"abstract": "Using a recently developed reconstruction method for photoacoustic tomography (PAT) valid for a planar measurement geometry parallel to a layered medium, we investigate the effects of shear wave propagation in the solid layer upon the ability to estimate Fourier components of the object. We examine this ability as a function of the thickness of the layer supporting shear waves as well as of the incidence angle of the field in the planewave representation. Examples are used to demonstrate the importance of accounting for shear waves in transcranial PAT. Error measures are introduced to quantify the error found when omitting shear waves from the forward model in PAT.",
"doi": "10.1117/1.JBO.17.6.061215",
"pmcid": "PMC3381031",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-06",
"series_number": "6",
"volume": "17",
"issue": "6",
"pages": "Art. No. 061215"
},
{
"id": "authors:ehac2-5b746",
"collection": "authors",
"collection_id": "ehac2-5b746",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160812-143631376",
"type": "article",
"title": "Photoacoustic computed tomography correcting for heterogeneity and attenuation",
"author": [
{
"family_name": "Huang",
"given_name": "Chao",
"clpid": "Huang-Chao"
},
{
"family_name": "Nie",
"given_name": "Liming",
"clpid": "Nie-Liming"
},
{
"family_name": "Schoonover",
"given_name": "Robert W.",
"clpid": "Schoonover-R-W"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
}
],
"abstract": "We report an investigation of image reconstruction in photoacoustic tomography for objects that possess heterogeneous material and acoustic attenuation distributions. When the object contains materials, such as bone and soft-tissue, that are modeled using power law attenuation models with distinct exponents, we demonstrate that the effects of acoustic attenuation due to the most strongly attenuating material can be compensated for if the attenuation of the other less attenuating material(s) are neglected. Experiments with phantom objects are presented to validated our findings.",
"doi": "10.1117/1.JBO.17.6.061211",
"pmcid": "PMC3380947",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-06",
"series_number": "6",
"volume": "17",
"issue": "6",
"pages": "Art. No. 061211"
},
{
"id": "authors:4tm3m-p5966",
"collection": "authors",
"collection_id": "4tm3m-p5966",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160809-101735482",
"type": "article",
"title": "Aberration correction for transcranial photoacoustic tomography of primates employing adjunct image data",
"author": [
{
"family_name": "Huang",
"given_name": "Chao",
"clpid": "Huang-Chao"
},
{
"family_name": "Nie",
"given_name": "Liming",
"clpid": "Nie-Liming"
},
{
"family_name": "Schoonover",
"given_name": "Robert W.",
"clpid": "Schoonover-R-W"
},
{
"family_name": "Guo",
"given_name": "Zijian",
"clpid": "Guo-Zijian"
},
{
"family_name": "Schirra",
"given_name": "Carsten O.",
"clpid": "Schirra-C-O"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A challenge in photoacoustic tomography (PAT) brain imaging is to compensate for aberrations in the measured photoacoustic data due to their propagation through the skull. By use of information regarding the skull morphology and composition obtained from adjunct x-ray computed tomography image data, we developed a subject-specific imaging model that accounts for such aberrations. A time-reversal-based reconstruction algorithm was employed with this model for image reconstruction. The image reconstruction methodology was evaluated in experimental studies involving phantoms and monkey heads. The results establish that our reconstruction methodology can effectively compensate for skull-induced acoustic aberrations and improve image fidelity in transcranial PAT.",
"doi": "10.1117/1.JBO.17.6.066016",
"pmcid": "PMC3381039",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-06",
"series_number": "6",
"volume": "17",
"issue": "6",
"pages": "Art. No. 066016"
},
{
"id": "authors:rmq9a-eqj37",
"collection": "authors",
"collection_id": "rmq9a-eqj37",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-145944485",
"type": "article",
"title": "Immediate alterations in intestinal oxygen saturation and blood flow after massive small bowel resection as measured by photoacoustic microscopy",
"author": [
{
"family_name": "Rowland",
"given_name": "Kathryn J.",
"clpid": "Rowland-K-J"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Erwin",
"given_name": "Christopher R.",
"clpid": "Erwin-C-R"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Warner",
"given_name": "Brad W.",
"clpid": "Warner-B-W"
}
],
"abstract": "Purpose:\nMassive small bowel resection (SBR) results in villus angiogenesis and a critical adaptation response within the remnant bowel. Previous ex vivo studies of intestinal blood flow after SBR are conflicting. We sought to determine the effect of SBR on intestinal hemodynamics using photoacoustic microscopy, a noninvasive, label-free, high-resolution in vivo hybrid imaging modality.\nMethods:\nPhotoacoustic microscopy was used to image the intestine microvascular system and measure blood flow and oxygen saturation (SO_2) of the terminal mesenteric arteriole and accompanying vein in C57BL6 mice (n = 7) before and immediately after a 50% proximal SBR. A P value of less than .05 was considered significant.\nResults:\nBefore SBR, arterial and venous SO_2 were similar. Immediately after SBR, the venous SO_2 decreased with an increase in the oxygen extraction fraction. In addition, the arterial and venous blood flow significantly decreased.\nConclusion:\nMassive SBR results in an immediate reduction in intestinal blood flow and increase in tissue oxygen utilization. These physiologic changes are observed throughout the remnant small intestine. The contribution of these early hemodynamic alterations may contribute to the induction of villus angiogenesis and the pathogenesis of normal intestinal adaptation responses.",
"doi": "10.1016/j.jpedsurg.2012.03.020",
"pmcid": "PMC3377986",
"issn": "0022-3468",
"publisher": "Elsevier",
"publication": "Journal of Pediatric Surgery",
"publication_date": "2012-06",
"series_number": "6",
"volume": "47",
"issue": "6",
"pages": "1143-1149"
},
{
"id": "authors:pnhpp-e8z02",
"collection": "authors",
"collection_id": "pnhpp-e8z02",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160816-152642132",
"type": "article",
"title": "Spectrally encoded photoacoustic microscopy using a digital mirror device",
"author": [
{
"family_name": "Wang",
"given_name": "Yu",
"orcid": "0000-0003-3589-9274",
"clpid": "Wang-Yu"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have developed spectrally encoded photoacoustic microscopy using a digital mirror device for multi-wavelength tomography, which enables fast spectral imaging of optical absorption. The optical illumination wavelengths are multiplexed at a laser pulse repetition rate of \u223c2\u2009\u2009kHz. Liquid samples, whole blood, and blood vessels in mouse ears were imaged. Compared with internal wavelength tuning of a narrow-band laser, external wavelength tuning based on a digital mirror device improves the data acquisition speed of spectral photoacoustic microscopy. Compared with external wavelength scanning of a wide-band laser with the same pulse energy, spectral encoding improves the signal-to-noise ratio.",
"doi": "10.1117/1.JBO.17.6.066020",
"pmcid": "PMC3381037",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-06",
"series_number": "6",
"volume": "17",
"issue": "6",
"pages": "Art. No. 066020"
},
{
"id": "authors:07jp8-wxs11",
"collection": "authors",
"collection_id": "07jp8-wxs11",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160810-090804039",
"type": "article",
"title": "In vivo three-dimensional photoacoustic imaging based on a clinical matrix array ultrasound probe",
"author": [
{
"family_name": "Wang",
"given_name": "Yu",
"orcid": "0000-0003-3589-9274",
"clpid": "Wang-Yu"
},
{
"family_name": "Erpelding",
"given_name": "Todd N.",
"clpid": "Erpelding-T-N"
},
{
"family_name": "Jankovic",
"given_name": "Ladislav",
"clpid": "Jankovic-L"
},
{
"family_name": "Guo",
"given_name": "Zijian",
"clpid": "Guo-Zijian"
},
{
"family_name": "Robert",
"given_name": "Jean-Luc",
"clpid": "Robert-J-L"
},
{
"family_name": "David",
"given_name": "Guillaume",
"clpid": "David-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present an integrated photoacoustic and ultrasonic three-dimensional (3-D) volumetric imaging system based on a two-dimensional (2-D) matrix array ultrasound probe. A wavelength-tunable dye laser pumped by a Q-switched Nd:YAG laser serves as the light source and a modified commercial ultrasound imaging system (iU22, Philips Healthcare) with a 2-D array transducer (X7-2, Philips Healthcare) detects both the pulse-echo ultrasound and photoacoustic signals. A multichannel data acquisition system acquires the RF channel data. The imaging system enables rendering of co-registered 3-D ultrasound and photoacoustic images without mechanical scanning. The resolution along the azimuth, elevation, and axial direction are measured to be 0.69, 0.90 and 0.84 mm for photoacoustic imaging. In vivo 3-D photoacoustic mapping of the sentinel lymph node was demonstrated in a rat model using methylene blue dye. These results highlight the clinical potential of 3-D PA imaging for identification of sentinel lymph nodes for cancer staging in humans.",
"doi": "10.1117/1.JBO.17.6.061208",
"pmcid": "PMC3380932",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-06",
"series_number": "6",
"volume": "17",
"issue": "6",
"pages": "Art. No. 061208"
},
{
"id": "authors:znmjs-qq753",
"collection": "authors",
"collection_id": "znmjs-qq753",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160812-160420969",
"type": "article",
"title": "Quantitative photoacoustic microscopy of optical absorption coefficients from acoustic spectra in the optical diffusive regime",
"author": [
{
"family_name": "Guo",
"given_name": "Zijian",
"clpid": "Guo-Zijian"
},
{
"family_name": "Favazza",
"given_name": "Christopher",
"clpid": "Favazza-C-P"
},
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic (PA) microscopy (PAM) can image optical absorption contrast with ultrasonic spatial resolution in the optical diffusive regime. Conventionally, accurate quantification in PAM requires knowledge of the optical fluence attenuation, acoustic pressure attenuation, and detection bandwidth. We circumvent this requirement by quantifying the optical absorption coefficients from the acoustic spectra of PA signals acquired at multiple optical wavelengths. With the acoustic spectral method, the absorption coefficients of an oxygenated bovine blood phantom at 560, 565, 570, and 575 nm were quantified with errors of <3%. We also quantified the total hemoglobin concentration and hemoglobin oxygen saturation in a live mouse. Compared with the conventional amplitude method, the acoustic spectral method provides greater quantification accuracy in the optical diffusive regime. The limitations of the acoustic spectral method was also discussed.",
"doi": "10.1117/1.JBO.17.6.066011",
"pmcid": "PMC3381032",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-06",
"series_number": "6",
"volume": "17",
"issue": "6",
"pages": "Art. No. 066011"
},
{
"id": "authors:3jdcv-9e716",
"collection": "authors",
"collection_id": "3jdcv-9e716",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160809-155107326",
"type": "article",
"title": "Functional photoacoustic microscopy of diabetic vasculature",
"author": [
{
"family_name": "Krumholz",
"given_name": "Arie",
"clpid": "Krumholz-A"
},
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We used functional photoacoustic microscopy to image diabetes-induced damage to the microvasculature. To produce an animal model for Type 1 diabetes, we used streptozotocin (STZ), which is particularly toxic to the insulin-producing beta cells of the pancreas in mammals. A set number of ND4 Swiss Webster mice received intraperitoneal injections of STZ for five consecutive days at 50\u2009mg/kg. Most mice developed a significant rise in blood glucose level (\u223c400\u2009mg/dL) within three weeks of the first injection. Changes in vasculature and hemodynamics were monitored for six weeks. The mouse ear was imaged with an optical-resolution photoacoustic microscope at a main blood vessel branch from the root of the ear. There are noticeable and measurable changes associated with the disease, including decreased vessel diameter and possible occlusion due to vessel damage and polyurea. We also observed an increase in the blood flow speed in the vein and a decrease in the artery, which could be due to compensation for the dehydration and vessel diameter changes. Functional and metabolic parameters such as hemoglobin oxygen saturation, oxygen extraction fraction, and oxygen consumption rate were also measured, but showed no significant change.",
"doi": "10.1117/1.JBO.17.6.060502",
"pmcid": "PMC3381042",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-06",
"series_number": "6",
"volume": "17",
"issue": "6",
"pages": "Art. No. 060502"
},
{
"id": "authors:k5ss4-5ts63",
"collection": "authors",
"collection_id": "k5ss4-5ts63",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160810-092345815",
"type": "article",
"title": "Label-free photoacoustic microscopy of myocardial sheet architecture",
"author": [
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Cheng",
"given_name": "Ya-Jian",
"clpid": "Cheng-Ya-Jian"
},
{
"family_name": "Chen",
"given_name": "Junjie",
"clpid": "Chen-Junjie"
},
{
"family_name": "Wickline",
"given_name": "Samuel",
"clpid": "Wickline-S-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Cardiac myofibers are organized into sheet architectures, which contribute to up to 40% of the heart wall thickening for ejection of blood for circulation. It is important to delineate the sheet architecture for a better understanding of cardiac mechanisms. However, current sheet imaging technologies are limited by fixation-induced dehydration/deformation and low spatial resolution. Here we implemented high-resolution label-free photoacoustic microscopy (PAM) of the myocardial sheet architecture. With high endogenous optical-absorption contrast originating mainly from cytochrome, myoglobin, and melanin, PAM can image the unfixed, unstained and unsliced heart without introducing deformation artifacts. A fresh blood-free mouse heart was imaged by PAM ex vivo. The three-dimensional branching sheets were clearly identified within 150 \u00b5m depth. Various morphological parameters were derived from the PAM image. The sheet thickness (80\u00b110\u2009\u2009\u03bcm) and the cleavage height (11\u00b11\u2009\u2009\u03bcm) were derived from an undehydrated heart for the first time. Therefore, PAM has the potential for the functional imaging of sheet architecture in ex vivo perfused and viable hearts.",
"doi": "10.1117/1.JBO.17.6.060506",
"pmcid": "PMC3379726",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-06",
"series_number": "6",
"volume": "17",
"issue": "6",
"pages": "Art. No. 060506"
},
{
"id": "authors:7jfap-80z02",
"collection": "authors",
"collection_id": "7jfap-80z02",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160812-120142249",
"type": "article",
"title": "Optimal ultraviolet wavelength for in vivo photoacoustic imaging of cell nuclei",
"author": [
{
"family_name": "Yao",
"given_name": "Da-Kang",
"clpid": "Yao-Da-Kang"
},
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In order to image noninvasively cell nuclei in vivo without staining, we have developed ultraviolet photoacoustic microscopy (UV-PAM), in which ultraviolet light excites nucleic acids in cell nuclei to produce photoacoustic waves. Equipped with a tunable laser system, the UV-PAM was applied to in vivo imaging of cell nuclei in small animals. We found that 250 nm was the optimal wavelength for in vivo photoacoustic imaging of cell nuclei. The optimal wavelength enables UV-PAM to image cell nuclei using as little as 2 nJ laser pulse energy. Besides the optimal wavelength, application of a wavelength between 245 and 275 nm can produce in vivo images of cell nuclei with specific, positive, and high optical contrast.",
"doi": "10.1117/1.JBO.17.5.056004",
"pmcid": "PMC3602808",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-05",
"series_number": "5",
"volume": "17",
"issue": "5",
"pages": "Art. No. 056004"
},
{
"id": "authors:gwbz7-reb41",
"collection": "authors",
"collection_id": "gwbz7-reb41",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160817-081407589",
"type": "article",
"title": "Whole-body ring-shaped confocal photoacoustic computed tomography of small animals in vivo",
"author": [
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Chatni",
"given_name": "Muhammad R.",
"clpid": "Chatni-M-R"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Guo",
"given_name": "Zijian",
"clpid": "Guo-Zijian"
},
{
"family_name": "Wang",
"given_name": "Kun",
"clpid": "Wang-Kun"
},
{
"family_name": "Anastasio",
"given_name": "Mark",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We report a novel small-animal whole-body imaging system called ring-shaped confocal photoacoustic computed tomography (RC-PACT). RC-PACT is based on a confocal design of free-space ring-shaped light illumination and 512-element full-ring ultrasonic array signal detection. The free-space light illumination maximizes the light delivery efficiency, and the full-ring signal detection ensures a full two-dimensional view aperture for accurate image reconstruction. Using cylindrically focused array elements, RC-PACT can image a thin cross section with 0.10 to 0.25 mm in-plane resolutions and 1.6\u2009s/frame acquisition time. By translating the mouse along the elevational direction, RC-PACT provides a series of cross-sectional images of the brain, liver, kidneys, and bladder.",
"doi": "10.1117/1.JBO.17.5.050506",
"pmcid": "PMC3382342",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-05",
"series_number": "5",
"volume": "17",
"issue": "5",
"pages": "Art. no. 050506"
},
{
"id": "authors:z05ep-05m92",
"collection": "authors",
"collection_id": "z05ep-05m92",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160812-142854532",
"type": "article",
"title": "Performance characterization of an integrated ultrasound, photoacoustic, and thermoacoustic imaging system",
"author": [
{
"family_name": "Ke",
"given_name": "Haixin",
"clpid": "Ke-Haixin"
},
{
"family_name": "Erpelding",
"given_name": "Todd N.",
"clpid": "Erpelding-T-N"
},
{
"family_name": "Jankovic",
"given_name": "Ladislav",
"clpid": "Jankovic-L"
},
{
"family_name": "Liu",
"given_name": "Changjun",
"orcid": "0000-0003-0079-6793",
"clpid": "Liu-Changjun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We developed a novel trimodality system for human breast imaging by integrating photoacoustic (PA) and thermoacoustic (TA) imaging techniques into a modified commercial ultrasound scanner. Because light was delivered with an optical assembly placed within the microwave antenna, no mechanical switching between the microwave and laser sources was needed. Laser and microwave excitation pulses were interleaved to enable PA and TA data acquisition in parallel at a rate of 10 frames per second. A tube (7 mm inner diameter) filled with oxygenated bovine blood or 30 mM methylene blue dye was successfully detected in PA images in chicken breast tissue at depths of 6.6 and 8.4 cm, respectively, for the first time. The SNRs at these depths reached \u223c24 and \u223c15\u2009\u2009dB, respectively, by averaging 200 signal acquisitions. Similarly, a tube (13 mm inner diameter) filled with saline solution (0.9%) at a depth of 4.4 cm in porcine fat tissue was successfully detected in TA images. The PA axial, lateral, and elevational resolutions were 640 \u03bcm, 720 \u03bcm, and 3.5 mm, respectively, suitable for breast cancer imaging. A PA noise-equivalent sensitivity to methylene blue solution of 260 nM was achieved in chicken tissue at a depth of 3.4 cm.",
"doi": "10.1117/1.JBO.17.5.056010",
"pmcid": "PMC3381021",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-05",
"series_number": "5",
"volume": "17",
"issue": "5",
"pages": "Art. No. 056010"
},
{
"id": "authors:e2jn6-6n823",
"collection": "authors",
"collection_id": "e2jn6-6n823",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160809-104529194",
"type": "article",
"title": "Dependence of photoacoustic speckles on boundary roughness",
"author": [
{
"family_name": "Guo",
"given_name": "Zijian",
"clpid": "Guo-Zijian"
},
{
"family_name": "Xu",
"given_name": "Zhun",
"clpid": "Xu-Zhun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Speckles have been considered ubiquitous in all scattering-based coherent imaging technologies. However, as an optical-absorption-based coherent imaging technology, photoacoustic (PA) tomography (PAT) suppresses speckles by building up prominent boundary signals. We theoretically study the dependence of PAT speckles on the boundary roughness, which is quantified by the root-mean-squared value and the correlation length of the boundary height. Both the speckle visibility and the correlation coefficient between the reconstructed and actual boundaries are quantified. If the root-mean-squared height fluctuation is much greater than, and the height correlation length is much smaller than the imaging resolution, the reconstructed boundaries become fully developed speckles. In other words, speckle formation requires large uncorrelated height fluctuations within the resolution cell. The first- and second-order statistics of PAT speckles are also studied experimentally. While the amplitude of the speckles follows a Gaussian distribution, the autocorrelation of the speckle patterns tracks that of the system point spread function.",
"doi": "10.1117/1.JBO.17.4.046009",
"pmcid": "PMC3380940",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-04",
"series_number": "4",
"volume": "17",
"issue": "4",
"pages": "Art. No. 046009"
},
{
"id": "authors:mwhtz-f9s96",
"collection": "authors",
"collection_id": "mwhtz-f9s96",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160809-110658192",
"type": "article",
"title": "Detection, Mapping, and Quantification of Single Walled Carbon Nanotubes in Histological Specimens with Photoacoustic Microscopy",
"author": [
{
"family_name": "Avti",
"given_name": "Pramod K.",
"clpid": "Avti-P-K"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Favazza",
"given_name": "Christopher",
"clpid": "Favazza-C-P"
},
{
"family_name": "Mikos",
"given_name": "Antonios G.",
"clpid": "Mikos-A-G"
},
{
"family_name": "Jansen",
"given_name": "John A.",
"clpid": "Jansen-J-A"
},
{
"family_name": "Shroyer",
"given_name": "Kenneth R.",
"clpid": "Shroyer-K-R"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Sitharaman",
"given_name": "Balaji",
"clpid": "Sitharaman-B"
}
],
"abstract": "Aims: In the present study, the efficacy of multi-scale photoacoustic microscopy (PAM) was investigated to detect, map, and quantify trace amounts [nanograms (ng) to micrograms (\u00b5g)] of SWCNTs in a variety of histological tissue specimens consisting of cancer and benign tissue biopsies (histological specimens from implanted tissue engineering scaffolds). \n\nMaterials and Methods: Optical-resolution (OR) and acoustic-resolution (AR) - Photoacoustic microscopy (PAM) was employed to detect, map and quantify the SWCNTs in a variety of tissue histological specimens and compared with other optical techniques (bright-field optical microscopy, Raman microscopy, near infrared (NIR) fluorescence microscopy). \n\nResults: Both optical-resolution and acoustic-resolution PAM, allow the detection and quantification of SWCNTs in histological specimens with scalable spatial resolution and depth penetration. The noise-equivalent detection sensitivity to SWCNTs in the specimens was calculated to be as low as \u223c7 pg. Image processing analysis further allowed the mapping, distribution, and quantification of the SWCNTs in the histological sections. \n\nConclusions: The results demonstrate the potential of PAM as a promising imaging technique to detect, map, and quantify SWCNTs in histological specimens, and could complement the capabilities of current optical and electron microscopy techniques in the analysis of histological specimens containing SWCNTs.",
"doi": "10.1371/journal.pone.0035064",
"pmcid": "PMC3322151",
"issn": "1932-6203",
"publisher": "Public Library of Science",
"publication": "PLoS ONE",
"publication_date": "2012-04",
"series_number": "4",
"volume": "7",
"issue": "4",
"pages": "Art. No. e35064"
},
{
"id": "authors:nnr02-prn17",
"collection": "authors",
"collection_id": "nnr02-prn17",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160816-103408103",
"type": "article",
"title": "Seeing it through: translational validation of new medical imaging modalities",
"author": [
{
"family_name": "Aldrich",
"given_name": "Melissa B.",
"clpid": "Aldrich-M-B"
},
{
"family_name": "Marshall",
"given_name": "Milton V.",
"clpid": "Marshall-M-V"
},
{
"family_name": "Sevick-Muraca",
"given_name": "Eva M.",
"clpid": "Sevick-Muraca-E-M"
},
{
"family_name": "Lanza",
"given_name": "Greg",
"clpid": "Lanza-G-M"
},
{
"family_name": "Kotyk",
"given_name": "John",
"clpid": "Kotyk-J"
},
{
"family_name": "Culver",
"given_name": "Joseph",
"clpid": "Culver-J-P"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Uddin",
"given_name": "Jashim",
"clpid": "Uddin-J"
},
{
"family_name": "Crews",
"given_name": "Brenda C.",
"clpid": "Crews-B-C"
},
{
"family_name": "Marnett",
"given_name": "Lawrence J.",
"clpid": "Marnett-L-J"
},
{
"family_name": "Liao",
"given_name": "Joseph C.",
"clpid": "Liao-Joseph-C"
},
{
"family_name": "Contag",
"given_name": "Chris",
"clpid": "Contag-C"
},
{
"family_name": "Crawford",
"given_name": "James M.",
"clpid": "Crawford-J-M"
},
{
"family_name": "Wang",
"given_name": "Ken",
"clpid": "Wang-Ken"
},
{
"family_name": "Reisdorph",
"given_name": "Bill",
"clpid": "Reisdorph-B"
},
{
"family_name": "Appelman",
"given_name": "Henry",
"clpid": "Appelman-H"
},
{
"family_name": "Turgeon",
"given_name": "D. Kim",
"clpid": "Turgeon-D-K"
},
{
"family_name": "Meyer",
"given_name": "Charles",
"clpid": "Meyer-C"
},
{
"family_name": "Wang",
"given_name": "Tom",
"clpid": "Wang-Tom"
}
],
"abstract": "Medical imaging is an invaluable tool for diagnosis, surgical guidance, and assessment of treatment efficacy. The Network for Translational Research (NTR) for Optical Imaging consists of four research groups working to \"bridge the gap\" between lab discovery and clinical use of fluorescence- and photoacoustic-based imaging devices used with imaging biomarkers. While the groups are using different modalities, all the groups face similar challenges when attempting to validate these systems for FDA approval and, ultimately, clinical use. Validation steps taken, as well as future needs, are described here. The group hopes to provide translational validation guidance for itself, as well as other researchers.",
"doi": "10.1364/BOE.3.000764",
"pmcid": "PMC3345805",
"issn": "2156-7085",
"publisher": "Optical Society of America",
"publication": "Biomedical Optics Express",
"publication_date": "2012-04",
"series_number": "4",
"volume": "3",
"issue": "4",
"pages": "764-776"
},
{
"id": "authors:r62hg-ak817",
"collection": "authors",
"collection_id": "r62hg-ak817",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160624-155701804",
"type": "article",
"title": "Multiscale Photoacoustic Microscopy of Single-Walled Carbon Nanotube-Incorporated Tissue Engineering Scaffolds",
"author": [
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Paratala",
"given_name": "Bhavna S.",
"clpid": "Paratala-B-S"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Sitharaman",
"given_name": "Balaji",
"clpid": "Sitharaman-B"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Three-dimensional polymeric scaffolds provide structural support and function as substrates for cells and bioactive molecules necessary for tissue regeneration. Noninvasive real-time imaging of scaffolds and/or the process of tissue formation within the scaffold remains a challenge. Microcomputed tomography, the widely used technique to characterize polymeric scaffolds, shows poor contrast for scaffolds immersed in biological fluids, thereby limiting its utilities under physiological conditions. In this article, multiscale photoacoustic microscopy (PAM), consisting of both acoustic-resolution PAM (AR-PAM) and optical-resolution PAM (OR-PAM), was employed to image and characterize single-walled carbon-nanotube (SWNT)\u2013incorporated poly(lactic-co-glycolic acid) polymer scaffolds immersed in biological buffer. SWNTs were incorporated to reinforce the mechanical properties of the scaffolds, and to enhance the photoacoustic signal from the scaffolds. By choosing excitation wavelengths of 570 and 638\u2009nm, multiscale PAM could spectroscopically differentiate the photoacoustic signals generated from blood and from carbon-nanotube-incorporated scaffolds. OR-PAM, providing a fine lateral resolution of 2.6\u2009\u03bcm with an adequate tissue penetration of 660\u2009\u03bcm, successfully quantified the average porosity and pore size of the scaffolds to be 86.5%\u00b11.2% and 153\u00b115\u2009\u03bcm in diameter, respectively. AR-PAM further extended the tissue penetration to 2\u2009mm at the expense of lateral resolution (45\u2009\u03bcm). Our results suggest that PAM is a promising tool for noninvasive real-time imaging and monitoring of tissue engineering scaffolds in vitro, and in vivo under physiological conditions.",
"doi": "10.1089/ten.tec.2011.0519",
"pmcid": "PMC3311878",
"issn": "1937-3384",
"publisher": "Mary Ann Liebert, Inc.",
"publication": "Tissue Engineering Part C: Methods",
"publication_date": "2012-03-26",
"series_number": "4",
"volume": "18",
"issue": "4",
"pages": "310-317"
},
{
"id": "authors:19whb-zay26",
"collection": "authors",
"collection_id": "19whb-zay26",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160630-102054201",
"type": "article",
"title": "Slow light for deep tissue imaging with ultrasound modulation",
"author": [
{
"family_name": "Zhang",
"given_name": "Huiliang",
"clpid": "Zhang-Huiliang"
},
{
"family_name": "Sabooni",
"given_name": "Mahmood",
"clpid": "Sabooni-M"
},
{
"family_name": "Rippe",
"given_name": "Lars",
"clpid": "Rippe-L"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Kr\u00f6ll",
"given_name": "Stefan",
"clpid": "Kr\u00f6ll-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Hemmer",
"given_name": "Philip R.",
"clpid": "Hemmer-P-R"
}
],
"abstract": "Slow light has been extensively studied for applications ranging from optical delay lines to single photon quantum storage. Here, we show that the time delay of slow-light significantly improves the performance of the narrowband spectral filters needed to optically detect ultrasound from deep inside highly scatteringtissue. We demonstrate this capability with a 9\u2009cm thick tissue phantom, having 10\u2009cm^(\u22121) reduced scattering coefficient, and achieve an unprecedented background-free signal. Based on the data, we project real time imaging at video rates in even thicker phantoms and possibly deep enough into real tissue for clinical applications like early cancer detection.",
"doi": "10.1063/1.3696307",
"pmcid": "PMC3326061",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2012-03-26",
"series_number": "13",
"volume": "100",
"issue": "13",
"pages": "Art. No. 131102"
},
{
"id": "authors:s7sqd-s4890",
"collection": "authors",
"collection_id": "s7sqd-s4890",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160608-155648428",
"type": "article",
"title": "Photoacoustic Tomography: In Vivo Imaging from Organelles to Organs",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
}
],
"abstract": "Photoacoustic tomography (PAT) can create multiscale multicontrast images of living biological structures ranging from organelles to organs. This emerging technology overcomes the high degree of scattering of optical photons in biological tissue by making use of the photoacoustic effect. Light absorption by molecules creates a thermally induced pressure jump that launches ultrasonic waves, which are received by acoustic detectors to form images. Different implementations of PAT allow the spatial resolution to be scaled with the desired imaging depth in tissue while a high depth-to-resolution ratio is maintained. As a rule of thumb, the achievable spatial resolution is on the order of 1/200 of the desired imaging depth, which can reach up to 7 centimeters. PAT provides anatomical, functional, metabolic, molecular, and genetic contrasts of vasculature, hemodynamics, oxygen metabolism, biomarkers, and gene expression. We review the state of the art of PAT for both biological and clinical studies and discuss future prospects.",
"doi": "10.1126/science.1216210",
"pmcid": "PMC3322413",
"issn": "0036-8075",
"publisher": "American Association for the Advancement of Science",
"publication": "Science",
"publication_date": "2012-03-23",
"series_number": "6075",
"volume": "335",
"issue": "6075",
"pages": "1458-1462"
},
{
"id": "authors:2ppcr-98949",
"collection": "authors",
"collection_id": "2ppcr-98949",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160816-155345267",
"type": "article",
"title": "Time-reversed ultrasonically encoded optical focusing in biological tissue",
"author": [
{
"family_name": "Lai",
"given_name": "Puxiang",
"clpid": "Lai-Puxiang"
},
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Liu",
"given_name": "Honglin",
"orcid": "0000-0003-2473-9056",
"clpid": "Liu-Honglin"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We report an experimental investigation of time-reversed ultrasonically encoded optical focusing in biological tissue. This technology combines the concepts of optical phase conjugation and ultrasound modulation of diffused coherent light. The ultrasonically encoded (or tagged) diffused light from a tissue sample is collected in reflection mode and interferes with a reference light in a photorefractive crystal (used as a phase conjugation mirror) to form a hologram. Then a time-reversed copy of the tagged light is generated and traces back the original trajectories to the ultrasonic focus inside the tissue sample. With our current setup, we can achieve a maximum penetration depth of 5 mm in a chicken breast sample and image optical contrasts within a tissue sample with a spatial resolution approximately equaling 1/\u221a2 of the ultrasound focal diameter.",
"doi": "10.1117/1.JBO.17.3.030506",
"pmcid": "PMC3380942",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-03",
"series_number": "3",
"volume": "17",
"issue": "3",
"pages": "Art. No. 030506"
},
{
"id": "authors:5699d-nyv11",
"collection": "authors",
"collection_id": "5699d-nyv11",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-154526422",
"type": "article",
"title": "Multimodal sentinel lymph node mapping with single-photon emission computed tomography (SPECT)/computed tomography (CT) and photoacoustic tomography",
"author": [
{
"family_name": "Akers",
"given_name": "Walter J.",
"clpid": "Akers-W-J"
},
{
"family_name": "Edwards",
"given_name": "W. Barry",
"clpid": "Edwards-W-B"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Xu",
"given_name": "Baogang",
"clpid": "Xu-Baogang"
},
{
"family_name": "Erpelding",
"given_name": "Todd N.",
"clpid": "Erpelding-T-N"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Achilefu",
"given_name": "Samuel",
"clpid": "Achilefu-S"
}
],
"abstract": "The identification of cancer cells in the lymph nodes surrounding a tumor is important in establishing a prognosis. Optical detection techniques such as fluorescence and photoacoustic tomography (PAT) have been reported in preclinical studies for noninvasive sentinel lymph node (SLN) mapping. A method for validation of these techniques is needed for clinical trials. We report the use of a multimodal optical-radionuclear contrast agent as a validation tool for PAT in a preclinical model. Methylene blue (MB) was radiolabeled with ^(125)I for multimodal SLN mapping and used in conjunction with MB to assess the feasibility of multimodal SLN mapping in a rat model by PAT and single-photon emission computed tomography (SPECT). MB provided sufficient contrast for identifying SLNs noninvasively with a PAT system adapted from a clinical ultrasound imaging system. The signal location was corroborated by SPECT using ^(125)I labeled MB. The translation of PAT into the clinic can be facilitated by a direct comparison with established imaging methods using a clinically relevant dual SPECT and photoacoustic imaging agent. The new high-resolution PAT is a promising technology for the sensitive and accurate SLN detection in cancer patients.",
"doi": "10.1016/j.trsl.2011.09.006",
"pmcid": "PMC3286037",
"issn": "1931-5244",
"publisher": "Elsevier",
"publication": "Translational Research",
"publication_date": "2012-03",
"series_number": "3",
"volume": "159",
"issue": "3",
"pages": "175-181"
},
{
"id": "authors:qdntq-ayp75",
"collection": "authors",
"collection_id": "qdntq-ayp75",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160812-151338825",
"type": "article",
"title": "Photoacoustic Sentinel Lymph Node Imaging with Self-Assembled Copper Neodecanoate Nanoparticles",
"author": [
{
"family_name": "Pan",
"given_name": "Dipanjan",
"clpid": "Pan-Dipanjan"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Yalaz",
"given_name": "Ceren",
"clpid": "Yalaz-C"
},
{
"family_name": "Senpan",
"given_name": "Angana",
"clpid": "Senpan-A"
},
{
"family_name": "Omanakuttan",
"given_name": "Karthik",
"clpid": "Omanakuttan-K"
},
{
"family_name": "Wickline",
"given_name": "Samuel A.",
"clpid": "Wickline-S-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Lanza",
"given_name": "Gregory M.",
"clpid": "Lanza-G-M"
}
],
"abstract": "Photoacoustic tomography (PAT) is emerging as a novel, hybrid, and non-ionizing imaging modality because of its satisfactory spatial resolution and high soft tissue contrast. PAT combines the advantages of both optical and ultrasonic imaging methods. It opens up the possibilities for noninvasive staging of breast cancer and may replace sentinel lymph node (SLN) biopsy in clinic in the near future. In this work, we demonstrate for the first time that copper can be used as a contrast metal for near-infrared detection of SLN using PAT. A unique strategy is adopted to encapsulate multiple copies of Cu as organically soluble small molecule complexes within a phospholipid-entrapped nanoparticle. The nanoparticles assumed a size of 80\u201390 nm, which is the optimum hydrodynamic diameter for its distribution throughout the lymphatic systems. These particles provided at least 6-fold higher signal sensitivity in comparison to blood, which is a natural absorber of light. We also demonstrated that high SLN detection sensitivity with PAT can be achieved in a rodent model. This work clearly demonstrates for the first time the potential use of copper as an optical contrast agent.",
"doi": "10.1021/nn203895n",
"pmcid": "PMC3289744",
"issn": "1936-0851",
"publisher": "American Chemical Society",
"publication": "ACS Nano",
"publication_date": "2012-02-28",
"series_number": "2",
"volume": "6",
"issue": "2",
"pages": "1260-1267"
},
{
"id": "authors:km580-h9154",
"collection": "authors",
"collection_id": "km580-h9154",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160706-143610682",
"type": "article",
"title": "A Facile and General Method for the Encapsulation of Different Types of Imaging Contrast Agents Within Micrometer-Sized Polymer Beads",
"author": [
{
"family_name": "Bai",
"given_name": "Meng-Yi",
"clpid": "Bai-Meng-Yi"
},
{
"family_name": "Moran",
"given_name": "Christine H.",
"clpid": "Moran-C-H"
},
{
"family_name": "Zhang",
"given_name": "Lei",
"orcid": "0000-0001-9031-4318",
"clpid": "Zhang-Lei"
},
{
"family_name": "Liu",
"given_name": "Changjun",
"orcid": "0000-0003-0079-6793",
"clpid": "Liu-Changjun"
},
{
"family_name": "Zhang",
"given_name": "Yu",
"orcid": "0000-0001-8938-1927",
"clpid": "Zhang-Yu"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "Polystyrene (PS) hollow beads with holes on the surfaces are employed as containers for quick loading and encapsulation of a variety of contrast enhancement agents: saline solutions for thermoacoustic tomography, iodinated organic compounds for micro-computed tomography, and perfluorooctane for magnetic resonance. Because of the hole on the surface of the PS hollow bead, the contrast agent to be encapsulated could quickly enter the hollow interior via direct flow rather than slow diffusion through the wall. After loading, the hole on the surface is conveniently sealed by annealing the sample at a temperature (e.g., 95 \u00b0C) slightly above the glass-transition temperature of PS. In vitro methods are also used to investigate the effectiveness of encapsulation by quantifying the contrast enhancement enabled by the contrast agents.",
"doi": "10.1002/adfm.201102582",
"pmcid": "PMC6924621",
"issn": "1616-301X",
"publisher": "Wiley",
"publication": "Advanced Functional Materials",
"publication_date": "2012-02-22",
"series_number": "4",
"volume": "22",
"issue": "4",
"pages": "764-770"
},
{
"id": "authors:m25fe-4b342",
"collection": "authors",
"collection_id": "m25fe-4b342",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160809-151801199",
"type": "article",
"title": "Double-illumination photoacoustic microscopy",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Puckett",
"given_name": "Ernest R.",
"clpid": "Puckett-E-R"
},
{
"family_name": "Rowland",
"given_name": "Kathryn J.",
"clpid": "Rowland-K-J"
},
{
"family_name": "Warner",
"given_name": "Brad W.",
"clpid": "Warner-B-W"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Recent developments of optical-resolution photoacoustic microscopy (OR-PAM) have improved its spatial resolution and imaging speed. However, the penetration depth of OR-PAM is still limited to \u223c1\u2009\u2009mm in tissue, owing to the strong tissue scattering. Here, we have developed double-illumination PAM (DI-PAM), which illuminates the sample from both top and bottom sides simultaneously. Through phantom and in vivo experiments, we have demonstrated for thin targets that DI-PAM has a penetration depth of \u223c2\u2009\u2009mm in tissue at 532 nm and a focal zone of 260 \u03bcm, both significant improvements over traditional reflection or transmission-mode OR-PAM.",
"doi": "10.1364/OL.37.000659",
"pmcid": "PMC3306616",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2012-02-15",
"series_number": "4",
"volume": "37",
"issue": "4",
"pages": "659-661"
},
{
"id": "authors:kw3j8-qmk39",
"collection": "authors",
"collection_id": "kw3j8-qmk39",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160706-150023634",
"type": "article",
"title": "Deep-Tissue Photoacoustic Tomography of a Genetically Encoded Near-Infrared Fluorescent Probe",
"author": [
{
"family_name": "Filonov",
"given_name": "Grigory S.",
"clpid": "Filonov-G-S"
},
{
"family_name": "Krumholz",
"given_name": "Arie",
"clpid": "Krumholz-A"
},
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Verkhusha",
"given_name": "Vladislav V.",
"orcid": "0000-0002-2083-8121",
"clpid": "Verkhusha-V-V"
}
],
"abstract": "Skin-deep: The combination of a near-infrared fluorescent protein (iRFP) and deep-tissue photoacoustic tomography clearly demonstrates the superiority of iRFP over other genetically encoded probes. Impressive resolution (280\u2005\u03bcm lateral and 75\u2005\u03bcm axial) was obtained at a depth of 4\u2005mm in a live animal, and volumetric images of a tumor were produced (see image), thus allowing the spatially resolved monitoring of its development.",
"doi": "10.1002/anie.201107026",
"pmcid": "PMC3293502",
"issn": "1433-7851",
"publisher": "Wiley",
"publication": "Angewandte Chemie International Edition",
"publication_date": "2012-02-06",
"series_number": "6",
"volume": "51",
"issue": "6",
"pages": "1448-1451"
},
{
"id": "authors:bscam-11155",
"collection": "authors",
"collection_id": "bscam-11155",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160816-094651280",
"type": "article",
"title": "Reflection-mode submicron-resolution in vivo photoacoustic microscopy",
"author": [
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Submicron-resolution photoacoustic microscopy (PAM) currently exists only in transmission mode, due to the technical difficulties of combining high numerical-aperture (NA) optical illumination with high NA acoustic detection. The lateral resolution of reflection-mode PAM has not reached <2\u2009\u2009\u03bcm in the visible light range. Here we develop the first reflection-mode submicron-resolution PAM system with a new compact design. By using a parabolic mirror to focus and reflect the photoacoustic waves, sufficient signals were collected for good sensitivity without distorting the optical focusing. By imaging nanospheres and a resolution test chart, the lateral resolution was measured to be \u223c0.5\u2009\u2009\u03bcm with an optical wavelength of 532 nm, an optical NA of 0.63. The axial resolution was measured at 15 \u03bcm. Here the axial resolution was measured by a different experiment with the lateral resolution measurement. But we didn't describe the details of axial resolution measurement due to space limit. The maximum penetration was measured at \u223c0.42\u2009\u2009mm in optical-scattering soft tissue. As a comparison, both the submicron-resolution PAM and a 2.4 \u03bcm-resolution PAM were used to image a mouse ear in vivo with the same optical wavelength and similar pulse energy. Capillaries were resolved better by the submicron-resolution PAM. Therefore, the submicron-resolution PAM is suitable for in vivo high-resolution imaging, or even subcellular imaging, of optical absorption.",
"doi": "10.1117/1.JBO.17.2.020501",
"pmcid": "PMC3380933",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-02",
"series_number": "2",
"volume": "17",
"issue": "2",
"pages": "Art. No. 020501"
},
{
"id": "authors:xvzb4-s0h14",
"collection": "authors",
"collection_id": "xvzb4-s0h14",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160614-101749401",
"type": "article",
"title": "JBO Setting New Records",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "2011 was another record year for JBO. The number of manuscript submissions reached nearly 750. The impact factor leaped to 3.188, with the 5-year combined impact factor at 3.659. The publication frequency changed to monthly starting in January. The manuscript review cycles have been shortened considerably without sacrificing quality of review. JBO is deeply indebted to the authors, reviewers, and editorial board members for their contributions to such marvelous achievements.",
"doi": "10.1117/1.JBO.17.2.020101",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2012-02",
"series_number": "2",
"volume": "17",
"issue": "2",
"pages": "Art. No. 020101"
},
{
"id": "authors:7472r-pe886",
"collection": "authors",
"collection_id": "7472r-pe886",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160810-075148864",
"type": "article",
"title": "In vivo imaging of epileptic activity using 2-NBDG, a fluorescent deoxyglucose analog",
"author": [
{
"family_name": "Tsytsarev",
"given_name": "Vassiliy",
"clpid": "Tsytsarev-V"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Parameswar",
"given_name": "Archana R.",
"clpid": "Parameswar-A-R"
},
{
"family_name": "Demchenko",
"given_name": "Alexei V.",
"clpid": "Demchenko-A-V"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Accurately locating epileptic foci has great importance in advancing the treatment of epilepsy. In this study, epileptic seizures were first induced by intracortical injection of 4-aminopyridine in rats. A fluorescent deoxyglucose substitute, 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (2-NBDG), was then continuously injected via the tail vein. Brain glucose metabolism was subsequently monitored by fluorescence imaging of 2-NBDG. The initial uptake rate of 2-NBDG at the injection site of 4-aminopyridine significantly exceeded that of the control injection site, which indicated local hypermetabolism induced by seizures. Our results show that 2-NBDG can be used for localizing epileptic foci.",
"doi": "10.1016/j.jneumeth.2011.09.005",
"pmcid": "PMC3221836",
"issn": "0165-0270",
"publisher": "Elsevier",
"publication": "Journal of Neuroscience Methods",
"publication_date": "2012-01-15",
"series_number": "1",
"volume": "203",
"issue": "1",
"pages": "136-140"
},
{
"id": "authors:xvqk5-yfn39",
"collection": "authors",
"collection_id": "xvqk5-yfn39",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190304-125703527",
"type": "article",
"title": "In Vivo Quantitative Evaluation of the Transport Kinetics of Gold Nanocages in a Lymphatic System by Noninvasive Photoacoustic Tomography",
"author": [
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Li",
"given_name": "Weiyang",
"clpid": "Li-Weiyang"
},
{
"family_name": "Kim",
"given_name": "Chul-Hong",
"clpid": "Kim-Chul-Hong"
},
{
"family_name": "Yuan",
"given_name": "Yuchen",
"clpid": "Yuan-Yuchen"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "Sentinel lymph node (SLN) biopsy has emerged as a preferred method for axillary lymph node staging of breast cancer, and imaging the SLN in three-dimensional space is a prerequisite for the biopsy. Conventional SLN mapping techniques based on the injection of an organic dye or a suspension of radioactive colloids suffer from invasive surgical operation for visual detection of the dye or hazardous radioactive components and low spatial resolution of Geiger counters in detecting the radioactive colloids. This work systematically investigates the use of gold nanocages (AuNCs) as a novel class of optical tracers for noninvasive SLN imaging by photoacoustic (PA) tomography in a rat model. The transport of AuNCs in a lymphatic system and uptake by the sentinel lymph node were evaluated by PA tomography on the axillary region of a rat. Quantification of AuNCs accumulated in the lymph node was achieved by correlating the data from PA imaging with the results from inductively-coupled plasma mass spectrometry. Several parameters were systematically evaluated and optimized, including the concentration, size, and surface charge of the AuNCs. These results are critical to the further development of this AuNC-based PA tomography system for noninvasive SLN imaging, providing valuable information for metastatic cancer staging.",
"doi": "10.1021/nn203124x",
"pmcid": "PMC3246549",
"issn": "1936-0851",
"publisher": "American Chemical Society",
"publication": "ACS Nano",
"publication_date": "2011-12-27",
"series_number": "12",
"volume": "5",
"issue": "12",
"pages": "9658-9667"
},
{
"id": "authors:wt5g1-f5281",
"collection": "authors",
"collection_id": "wt5g1-f5281",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160708-091728581",
"type": "article",
"title": "Performance benchmarks of an array-based hand-held photoacoustic probe adapted from a clinical ultrasound system for non-invasive sentinel lymph node imaging",
"author": [
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Erpelding",
"given_name": "Todd N.",
"clpid": "Erpelding-T-N"
},
{
"family_name": "Jankovic",
"given_name": "Ladislav",
"clpid": "Jankovic-L"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Clinical translation of photoacoustic (PA) imaging can be facilitated by integration with commercial ultrasound (US) scanners to enable dual-modality imaging. An array-based US scanner was modified for hand-held PA imaging. The performance was benchmarked in terms of signal-to-noise ratio (SNR), axial spatial resolution and sensitivity. PA images of a tube, filled with methylene blue (MB; approx. 30\u2009mM) and placed at various depths in chicken tissue, were acquired. A 5\u2009cm penetration depth was achieved with an 18.6\u2009dB SNR using a laser fluence of 3\u2009mJ\u2009cm^(\u22122), only one-seventh of the safety limit (20\u2009mJ\u2009cm^(\u22122)). An axial resolution of approximately 400\u2009\u03bcm was maintained at all imaging depths. The PA sensitivity to MB placed 2.3\u2009cm deep in chicken tissue was less than 100\u2009\u03bcM. Further, after intradermal injection of MB (approx. 30\u2009mM), a rat sentinel lymph node was clearly identified in vivo, beneath a 3.8\u2009cm thick layer of chicken breast. The accumulated concentration of MB in the node was estimated to be approximately 7\u2009mM. The noise-equivalent sensitivities (approx. 2\u2009cm depth) were 17 and 85\u2009\u03bcM, ex vivo and in vivo, respectively. These results support the use of this PA system for non-invasive mapping and image-guided needle biopsy of sentinel nodes in breast cancer patients.",
"doi": "10.1098/rsta.2010.0353",
"pmcid": "PMC3263783",
"issn": "1364-503X",
"publisher": "Royal Society of London",
"publication": "Philosophical Transactions A: Mathematical, Physical and Engineering Sciences",
"publication_date": "2011-11-28",
"series_number": "1955",
"volume": "369",
"issue": "1955",
"pages": "4644-4650"
},
{
"id": "authors:wmj0j-gqz79",
"collection": "authors",
"collection_id": "wmj0j-gqz79",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160708-083655411",
"type": "article",
"title": "Effects of Photoacoustic Imaging and Photothermal Ablation Therapy Mediated by Targeted Hollow Gold Nanospheres in an Orthotopic Mouse Xenograft Model of Glioma",
"author": [
{
"family_name": "Lu",
"given_name": "Wei",
"clpid": "Lu-Wei"
},
{
"family_name": "Melancon",
"given_name": "Marites P.",
"clpid": "Melancon-M-P"
},
{
"family_name": "Xiong",
"given_name": "Chiyi",
"clpid": "Xiong-Chiyi"
},
{
"family_name": "Huang",
"given_name": "Qian",
"clpid": "Huang-Qian"
},
{
"family_name": "Elliott",
"given_name": "Andrew",
"clpid": "Elliott-A"
},
{
"family_name": "Song",
"given_name": "Shaoli",
"clpid": "Song-Shaoli"
},
{
"family_name": "Zhang",
"given_name": "Rui",
"clpid": "Zhang-Rui"
},
{
"family_name": "Flores",
"given_name": "Leo G., II",
"clpid": "Flores-L-G-II"
},
{
"family_name": "Gelovani",
"given_name": "Juri G.",
"clpid": "Gelovani-J-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Stafford",
"given_name": "R. Jason",
"clpid": "Stafford-R-J"
},
{
"family_name": "Li",
"given_name": "Chun",
"clpid": "Li-Chun"
}
],
"abstract": "Advancements in nanotechnology have made it possible to create multifunctional nanostructures that can be used simultaneously to image and treat cancers. For example, hollow gold nanospheres (HAuNS) have been shown to generate intense photoacoustic signals and induce efficient photothermal ablation (PTA) therapy. In this study, we used photoacoustic tomography, a hybrid imaging modality, to assess the intravenous delivery of HAuNS targeted to integrins that are overexpressed in both glioma and angiogenic blood vessels in a mouse model of glioma. Mice were then treated with near-infrared laser, which elevated tumor temperature by 20.7\u00b0C. We found that PTA treatment significantly prolonged the survival of tumor-bearing mice. Taken together, these results show the feasibility of using a single nanostructure for image-guided local tumor PTA therapy with photoacoustic molecular imaging.",
"doi": "10.1158/0008-5472.CAN-10-4557",
"pmcid": "PMC3185126",
"issn": "0008-5472",
"publisher": "American Association for Cancer Research",
"publication": "Cancer Research",
"publication_date": "2011-10-01",
"series_number": "19",
"volume": "71",
"issue": "19",
"pages": "6116-6121"
},
{
"id": "authors:8zkv1-dk805",
"collection": "authors",
"collection_id": "8zkv1-dk805",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180918-140711597",
"type": "article",
"title": "Functional photoacoustic microscopy of pH",
"author": [
{
"family_name": "Chatni",
"given_name": "Muhammad Rameez",
"clpid": "Chatni-M-R"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Danielli",
"given_name": "Amos",
"clpid": "Danielli-A"
},
{
"family_name": "Favazza",
"given_name": "Christopher P.",
"clpid": "Favazza-C-P"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "pH is a tightly regulated indicator of metabolic activity. In mammalian systems, an imbalance of pH regulation may result from or result in serious illness. In this paper, we report photoacoustic microscopy (PAM) of a commercially available pH-sensitive fluorescent dye (SNARF-5F carboxylic acid) in tissue phantoms. We demonstrated that PAM is capable of pH imaging in absolute values at tissue depths of up to 2.0 mm, greater than possible with other forms of optical microscopy.",
"doi": "10.1117/1.3644495",
"pmcid": "PMC3210191",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2011-10",
"series_number": "10",
"volume": "16",
"issue": "10",
"pages": "Art. No. 100503"
},
{
"id": "authors:avy3y-gg611",
"collection": "authors",
"collection_id": "avy3y-gg611",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160711-152933233",
"type": "article",
"title": "Nonionizing photoacoustic cystography in vivo",
"author": [
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Jeon",
"given_name": "Mansik",
"clpid": "Jeon-Mansik"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We demonstrate the feasibility of a novel and nonionizing process for bladder imaging in vivo, called photoacoustic cystography (PAC). Using a photoacoustic imaging system, we have successfully imaged a rat bladder filled with clinically used Methylene Blue (MB) dye. An image contrast of ~8 was achieved. Further, spectroscopic PAC confirmed the accumulation of MB in the bladder. Using a laser pulse energy of less than 1\u2009mJ/cm^2 (1/20 of the ANSI safety limit), a deeply (1.2\u2009cm) positioned bladder in biological tissues was clearly visible in the PA image. Our results suggest that PAC can potentially provide a nonionizing, relatively cheap, and portable tool for bladder mapping. Among our clinical interests, nonionizing PAC with an injection of MB can potentially monitor vesicoureteral reflux in children.",
"doi": "10.1364/OL.36.003599",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2011-09-15",
"series_number": "18",
"volume": "36",
"issue": "18",
"pages": "3599-3601"
},
{
"id": "authors:xee5d-5bm88",
"collection": "authors",
"collection_id": "xee5d-5bm88",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191212-105211172",
"type": "article",
"title": "Gold nanocages as contrast agents for photoacoustic imaging",
"author": [
{
"family_name": "Li",
"given_name": "Weiyang",
"clpid": "Li-Weiyang"
},
{
"family_name": "Brown",
"given_name": "Paige K.",
"clpid": "Brown-P-K"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "Gold nanoparticles with tunable absorption and scattering properties have been developed as contrast agents for various optical imaging techniques. As a hybrid modality that combines the merits of both optical and ultrasonic imaging, photoacoustic (PA) imaging also benefits from the use of these nanoparticles to greatly enhance the contrast for visualization of structures and biomarkers in biological tissues. Gold nanocages characterized by hollow interiors, ultrathin and porous walls are of particular interest for in vivo PA imaging because of their compact sizes, bio\u2010inertness and well\u2010defined surface chemistry, as well as their strong and highly wavelength\u2010tunable optical absorption in the near\u2010infrared (NIR) optical window of soft tissues. This review discusses the application of gold nanocages as a new class of contrast agents for PA imaging in the context of cancer diagnosis.",
"doi": "10.1002/cmmi.439",
"pmcid": "PMC6942690",
"issn": "1555-4309",
"publisher": "Wiley",
"publication": "Contrast Media & Molecular Imaging",
"publication_date": "2011-09",
"series_number": "5",
"volume": "6",
"issue": "5",
"pages": "370-377"
},
{
"id": "authors:cwqep-kxj58",
"collection": "authors",
"collection_id": "cwqep-kxj58",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180925-090943065",
"type": "article",
"title": "Three-dimensional photoacoustic tomography based on the focal-line concept",
"author": [
{
"family_name": "Xia",
"given_name": "Jun",
"clpid": "Xia-Jun"
},
{
"family_name": "Guo",
"given_name": "Zijian",
"clpid": "Guo-Zijian"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Aguirre",
"given_name": "Andres",
"clpid": "Aguirre-A"
},
{
"family_name": "Zhu",
"given_name": "Quing",
"clpid": "Zhu-Quing"
},
{
"family_name": "Percival",
"given_name": "Christopher",
"clpid": "Percival-C"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A full ring ultrasonic array-based photoacoustic tomography system was recently developed for small animal brain imaging. The 512-element array is cylindrically focused in the elevational direction, and can acquire a two-dimensional (2D) image in 1.6 s. In this letter, we demonstrate the three-dimensional (3D) imaging capability of this system. A novel 3D reconstruction algorithm was developed based on the focal-line concept. Compared to 3D images acquired simply by stacking a series of 2D images, the 3D focal-line reconstruction method renders images with much less artifacts, and improves the elevational resolution by 30% and the signal-to-noise ratio by two times. The effectiveness of the proposed algorithm was first validated by numerical simulations and then demonstrated with a hair phantom experiment and an ex vivo mouse embryo experiment.",
"doi": "10.1117/1.3625576",
"pmcid": "PMC3188639",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2011-09",
"series_number": "9",
"volume": "16",
"issue": "9",
"pages": "Art. No. 090505"
},
{
"id": "authors:f5vax-p6w41",
"collection": "authors",
"collection_id": "f5vax-p6w41",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190304-125703626",
"type": "article",
"title": "Photoacoustic tomography: fundamentals, advances and prospects",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical microscopy has been contributing to the development of life science for more than three centuries. However, due to strong optical scattering in tissue, its in vivo imaging ability has been restricted to studies at superficial depths. Advances in photoacoustic tomography (PAT) now allow multiscale imaging at depths from sub-millimeter to several centimeters, with spatial resolutions from sub-micrometer to sub-millimeter. Because of this high scalability and its unique optical absorption contrast, PAT is capable of performing anatomical, functional, molecular and fluid-dynamic imaging at various system levels, and is playing an increasingly important role in fundamental biological research and clinical practice. This Review discusses recent technical progress in PAT and presents corresponding applications. It ends with a discussion of several prospects and their technical challenges.",
"doi": "10.1002/cmmi.443",
"pmcid": "PMC3205414",
"issn": "1555-4309",
"publisher": "Wiley",
"publication": "Contrast Media & Molecular Imaging",
"publication_date": "2011-09",
"series_number": "5",
"volume": "6",
"issue": "5",
"pages": "332-345"
},
{
"id": "authors:fqk7b-f8162",
"collection": "authors",
"collection_id": "fqk7b-f8162",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180921-105125387",
"type": "article",
"title": "Quantitative photoacoustic imaging: correcting for heterogeneous light fluence distributions using diffuse optical tomography",
"author": [
{
"family_name": "Bauer",
"given_name": "Adam Q.",
"clpid": "Bauer-A-Q"
},
{
"family_name": "Nothdurft",
"given_name": "Ralph E.",
"clpid": "Nothdurft-R-E"
},
{
"family_name": "Erpelding",
"given_name": "Todd N.",
"clpid": "Erpelding-T-N"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Culver",
"given_name": "Joseph P.",
"clpid": "Culver-J-P"
}
],
"abstract": "The specificity of molecular and functional photoacoustic (PA) images depends on the accuracy of the photoacoustic absorption spectroscopy. The PA signal is proportional to the product of the optical absorption coefficient and local light fluence; quantitative PA measurements of the optical absorption coefficient therefore require an accurate estimation of optical fluence. Light-modeling aided by diffuse optical tomography (DOT) can be used to map the required fluence and to reduce errors in traditional PA spectroscopic analysis. As a proof-of-concept, we designed a tissue-mimicking phantom to demonstrate how fluence-related artifacts in PA images can lead to misrepresentations of tissue properties. To correct for these inaccuracies, the internal fluence in the tissue phantom was estimated by using DOT to reconstruct spatial distributions of the absorption and reduced scattering coefficients of multiple targets within the phantom. The derived fluence map, which only consisted of low spatial frequency components, was used to correct PA images of the phantom. Once calibrated to a known absorber, this method reduced errors in estimated absorption coefficients from 33% to 6%. These results experimentally demonstrate that combining DOT with PA imaging can significantly reduce fluence-related errors in PA images, while producing quantitatively accurate, high-resolution images of the optical absorption coefficient.",
"doi": "10.1117/1.3626212",
"pmcid": "PMC3188642",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2011-09",
"series_number": "9",
"volume": "16",
"issue": "9",
"pages": "Art. No. 096016"
},
{
"id": "authors:qe7mv-mw309",
"collection": "authors",
"collection_id": "qe7mv-mw309",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191212-105211269",
"type": "article",
"title": "Recent advances in colloidal gold nanobeacons for molecular photoacoustic imaging",
"author": [
{
"family_name": "Pan",
"given_name": "Dipanjan",
"clpid": "Pan-Dipanjan"
},
{
"family_name": "Pramanik",
"given_name": "Manojit",
"clpid": "Pramanik-M"
},
{
"family_name": "Wickline",
"given_name": "Samuel A.",
"clpid": "Wickline-S-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Lanza",
"given_name": "Gregory M.",
"clpid": "Lanza-G-M"
}
],
"abstract": "Photoacoustic imaging (PAI) represents a hybrid, nonionizing modality, which has been of particular interest because of its satisfactory spatial resolution and high soft tissue contrast. PAI has the potential to provide both functional and molecular imaging in vivo since optical absorption is sensitive to physiological parameters. In this review we summarize our effort to advance molecular PAI with colloidal gold nanobeacons (GNB). GNB represents a robust nanoparticle platform that entraps multiple copies of tiny gold nanoparticles (2\u20134\u2009nm) within a larger colloidal particle encapsulated by biocompatible synthetic or natural amphilines. The utilization of numerous small gold particles greatly amplifies the signal without exceeding the renal elimination threshold size. With fibrin\u2010targeted GNB, the robust detection of microthrombus formed over a ruptured atherosclerotic plaque has been achieved, which offers an important opportunity to recognize patients with moderate lumen stenosis but high risk of stroke. With the use of second\u2010generation smaller GNBs, the potential to improve sentinel lymph node assessment and biopsy was advanced with respect to rapidity and sensitivity of detection in mice. Finally, for angiogenesis, an essential microanatomical biomarker of tumor and cardiovascular disease progression, integrin\u2010targeted GNBs allowed visualization of numerous angiogenic sprouts and bridges that were otherwise undetectable from inherent blood signal alone, offering sensitive and specific discrimination and quantification of angiogenesis in vivo.",
"doi": "10.1002/cmmi.449",
"issn": "1555-4309",
"publisher": "Wiley",
"publication": "Contrast Media & Molecular Imaging",
"publication_date": "2011-09",
"series_number": "5",
"volume": "6",
"issue": "5",
"pages": "378-388"
},
{
"id": "authors:w043x-ndw55",
"collection": "authors",
"collection_id": "w043x-ndw55",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170314-135208107",
"type": "article",
"title": "Photoacoustic Microscopy Unlocks Secrets of Optical Absorption",
"author": [
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In vivo, label-free subwavelength-resolution photoacoustic microscopy enables more precise measurement of optical absorption \u2013 and, therefore, offers more information.",
"issn": "1081-8693",
"publisher": "Laurin Publishing Co Inc.",
"publication": "Biophotonics",
"publication_date": "2011-09"
},
{
"id": "authors:5s8pb-shc76",
"collection": "authors",
"collection_id": "5s8pb-shc76",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160830-081358386",
"type": "article",
"title": "VEGF is essential for hypoxia-inducible factor-mediated neovascularization but dispensable for endothelial sprouting",
"author": [
{
"family_name": "Oladipupo",
"given_name": "Sunday",
"orcid": "0000-0001-6555-0693",
"clpid": "Oladipupo-Sunday-S"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Kovalski",
"given_name": "Joanna",
"clpid": "Kovalski-Joanna-R"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Santeford",
"given_name": "Andrea",
"clpid": "Santeford-Andrea-C"
},
{
"family_name": "Sohn",
"given_name": "Rebecca E.",
"clpid": "Sohn-Rebecca-E"
},
{
"family_name": "Shohet",
"given_name": "Ralph",
"clpid": "Shohet-Ralph-V"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-Konstantin-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Arbeit",
"given_name": "Jeffrey M.",
"clpid": "Arbeit-Jeffrey-M"
}
],
"abstract": "Although our understanding of the molecular regulation of adult neovascularization has advanced tremendously, vascular-targeted therapies for tissue ischemia remain suboptimal. The master regulatory transcription factors of the hypoxia-inducible factor (HIF) family are attractive therapeutic targets because they coordinately up-regulate multiple genes controlling neovascularization. Here, we used an inducible model of epithelial HIF-1 activation, the TetON-HIF-1 mouse, to test the requirement for VEGF in HIF-1 mediated neovascularization. TetON-HIF-1, K14-Cre, and VEGF^(flox/flox) alleles were combined to create TetON-HIF-1:VEGF\u0394 mice to activate HIF-1 and its target genes in adult basal keratinocytes in the absence of concomitant VEGF. HIF-1 induction failed to produce neovascularization in TetON-HIF-1:VEGF\u0394 mice despite robust up-regulation of multiple proangiogenic HIF targets, including PlGF, adrenomedullin, angiogenin, and PAI-1. In contrast, endothelial sprouting was preserved, enhanced, and more persistent, consistent with marked reduction in Dll4-Notch-1 signaling. Optical-resolution photoacoustic microscopy, which provides noninvasive, label-free, high resolution, and wide-field vascular imaging, revealed the absence of both capillary expansion and arteriovenous remodeling in serially imaged individual TetON-HIF-1:VEGF\u0394 mice. Impaired TetON-HIF-1:VEGF\u0394 neovascularization could be partially rescued by 12-O-tetradecanoylphorbol-13-acetate skin treatment. These data suggest that therapeutic angiogenesis for ischemic cardiovascular disease may require treatment with both HIF-1 and VEGF.",
"doi": "10.1073/pnas.1101321108",
"pmcid": "PMC3156154",
"issn": "0027-8424",
"publisher": "National Academy of Sciences",
"publication": "Proceedings of the National Academy of Sciences of the United States of America",
"publication_date": "2011-08-09",
"series_number": "32",
"volume": "108",
"issue": "32",
"pages": "13264-13269"
},
{
"id": "authors:ny5f1-19z08",
"collection": "authors",
"collection_id": "ny5f1-19z08",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160701-124434057",
"type": "article",
"title": "Noninvasive Photoacoustic Microscopy of Living Cells in Two and Three Dimensions through Enhancement by a Metabolite Dye",
"author": [
{
"family_name": "Zhang",
"given_name": "Yu",
"orcid": "0000-0001-8938-1927",
"clpid": "Zhang-Yu"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Wang",
"given_name": "Yu",
"orcid": "0000-0003-3589-9274",
"clpid": "Wang-Yu"
},
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Li",
"given_name": "Li",
"clpid": "Li-Li"
},
{
"family_name": "Choi",
"given_name": "Sung-Wook",
"clpid": "Choi-Sung-Wook"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "A new type of contrast agent, 1-(4,5-dimethyl-2-thiazolyl)-3,5-diphenylformazan (MTT formazan), is reported for nondestructive and nontoxic imaging of living cells by photoacoustic microscopy (see picture). The contrast mechanism is general and can be applied to essentially all types of metabolically active cells, including stem cells and tumor cells.",
"doi": "10.1002/anie.201101659",
"pmcid": "PMC3149874",
"issn": "1433-7851",
"publisher": "Wiley",
"publication": "Angewandte Chemie International Edition",
"publication_date": "2011-08-01",
"series_number": "32",
"volume": "50",
"issue": "32",
"pages": "7359-7363"
},
{
"id": "authors:g6021-hkw44",
"collection": "authors",
"collection_id": "g6021-hkw44",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160829-130220950",
"type": "article",
"title": "Photoacoustic microscopy of tyrosinase reporter gene in vivo",
"author": [
{
"family_name": "Krumholz",
"given_name": "Arie",
"clpid": "Krumholz-A"
},
{
"family_name": "VanVickle-Chavez",
"given_name": "Sarah J.",
"clpid": "VanVickle-Chavez-S-J"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Fleming",
"given_name": "Timothy P.",
"clpid": "Fleming-T-P"
},
{
"family_name": "Gillanders",
"given_name": "William E.",
"clpid": "Gillanders-W-E"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography is a hybrid modality based on optical absorption excitation and ultrasonic detection. It is sensitive to melanin, one of the primary absorbers in skin. For cells that do not naturally contain melanin, melanin production can be induced by introducing the gene for tyrosinase, the primary enzyme responsible for expression of melanin in melanogenic cells. Optical resolution photoacoustic microscopy was used in the ex vivo study reported here, where the signal from transfected cells increased by more than 10 times over wild-type cells. A subsequent in vivo experiment was conducted to demonstrate the capability of photoacoustic microscopy to spectrally differentiate between tyrosinase-catalyzed melanin and various other absorbers in tissue.",
"doi": "10.1117/1.3606568",
"pmcid": "PMC3162617",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2011-08",
"series_number": "8",
"volume": "16",
"issue": "8",
"pages": "Art. No. 080503"
},
{
"id": "authors:4p3yv-dnx17",
"collection": "authors",
"collection_id": "4p3yv-dnx17",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160830-075253136",
"type": "article",
"title": "Time-reversed ultrasonically encoded optical focusing into tissue-mimicking media with thickness up to 70 mean free paths",
"author": [
{
"family_name": "Liu",
"given_name": "Honglin",
"orcid": "0000-0003-2473-9056",
"clpid": "Liu-Honglin"
},
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Lai",
"given_name": "Puxiang",
"clpid": "Lai-Puxiang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In turbid media such as biological tissue, multiple scattering hinders direct light focusing at depths beyond one transport mean free path. As a solution to this problem, time-reversed ultrasonically encoded (TRUE) optical focusing is proposed based on ultrasonic encoding of diffused laser light and optical time reversal. In TRUE focusing, a laser beam of long coherence length illuminates a turbid medium, where the incident light undergoes multiple scattering and part of it gets ultrasonically encoded within the ultrasonic focal zone. A conjugated wavefront of the ultrasonically encoded light is then generated by a phase conjugate mirror outside the medium, which traces back the trajectories of the ultrasonically encoded diffused light and converges light to the ultrasonic focal zone. Here, we report the latest experimental improvement in TRUE optical focusing that increases its penetration in tissue-mimicking media from a thickness of 3.75 to 7.00 mm. We also demonstrate that the TRUE focus depends on the focal diameter of the ultrasonic transducer.",
"doi": "10.1117/1.3609004",
"pmcid": "PMC3162620",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2011-08",
"series_number": "8",
"volume": "16",
"issue": "8",
"pages": "Art. No. 086009"
},
{
"id": "authors:ss4q6-trt33",
"collection": "authors",
"collection_id": "ss4q6-trt33",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160829-144259641",
"type": "article",
"title": "Reflection-mode time-reversed ultrasonically encoded optical focusing into turbid media",
"author": [
{
"family_name": "Lai",
"given_name": "Puxiang",
"clpid": "Lai-Puxiang"
},
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Liu",
"given_name": "Honglin",
"orcid": "0000-0003-2473-9056",
"clpid": "Liu-Honglin"
},
{
"family_name": "Suzuki",
"given_name": "Yuta",
"clpid": "Suzuki-Yuta"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Time-reversed ultrasonically encoded (TRUE) optical focusing was recently proposed to deliver light dynamically to a tight region inside a scattering medium. In this letter, we report the first development of a reflection-mode TRUE optical focusing system. A high numerical aperture light guide is used to transmit the diffusely reflected light from a turbid medium to a phase-conjugate mirror (PCM), which is sensitive only to the ultrasound-tagged light. From the PCM, a phase conjugated wavefront of the tagged light is generated and conveyed by the same light guide back to the turbid medium, subsequently converging to the ultrasonic focal zone. We present experimental results from this system, which has the ability to focus light in a highly scattering medium with a round-trip optical penetration thickness (extinction coefficient multiplied by round-trip depth) as large as 160.",
"doi": "10.1117/1.3609001",
"pmcid": "PMC3166339",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2011-08",
"series_number": "8",
"volume": "16",
"issue": "8",
"pages": "Art. No. 080505"
},
{
"id": "authors:368ry-3by80",
"collection": "authors",
"collection_id": "368ry-3by80",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160819-133957547",
"type": "article",
"title": "Label-free oxygen-metabolic photoacoustic microscopy in vivo",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Zhang",
"given_name": "Yu",
"orcid": "0000-0001-8938-1927",
"clpid": "Zhang-Yu"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Almost all diseases, especially cancer and diabetes, manifest abnormal oxygen metabolism. Accurately measuring the metabolic rate of oxygen (MRO_2) can be helpful for fundamental pathophysiological studies, and even early diagnosis and treatment of disease. Current techniques either lack high resolution or rely on exogenous contrast. Here, we propose label-free metabolic photoacoustic microscopy (mPAM) with small vessel resolution to noninvasively quantify MRO_2 in vivo in absolute units. mPAM is the unique modality for simultaneously imaging all five anatomical, chemical, and fluid-dynamic parameters required for such quantification: tissue volume, vessel cross-section, concentration of hemoglobin, oxygen saturation of hemoglobin, and blood flow speed. Hyperthermia, cryotherapy, melanoma, and glioblastoma were longitudinally imaged in vivo. Counterintuitively, increased MRO_2 does not necessarily cause hypoxia or increase oxygen extraction. In fact, early-stage cancer was found to be hyperoxic despite hypermetabolism.",
"doi": "10.1117/1.3594786",
"pmcid": "PMC3144973",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2011-07",
"series_number": "7",
"volume": "16",
"issue": "7",
"pages": "Art. No. 076003"
},
{
"id": "authors:rbftp-g0z60",
"collection": "authors",
"collection_id": "rbftp-g0z60",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160829-125526262",
"type": "article",
"title": "Photoacoustic microscopy of microvascular responses to cortical electrical stimulation",
"author": [
{
"family_name": "Tsytsarev",
"given_name": "Vassiliy",
"clpid": "Tsytsarev-V"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Barbour",
"given_name": "Dennis L.",
"clpid": "Barbour-D-L"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Advances in the functional imaging of cortical hemodynamics have greatly facilitated the understanding of neurovascular coupling. In this study, label-free optical-resolution photoacoustic microscopy (OR-PAM) was used to monitor microvascular responses to direct electrical stimulations of the mouse somatosensory cortex through a cranial opening. The responses appeared in two forms: vasoconstriction and vasodilatation. The transition between these two forms of response was observed in single vessels by varying the stimulation intensity. Marked correlation was found between the current-dependent responses of two daughter vessels bifurcating from the same parent vessel. Statistical analysis of twenty-seven vessels from three different animals further characterized the spatial-temporal features and the current dependence of the microvascular response. Our results demonstrate that OR-PAM is a valuable tool to study neurovascular coupling at the microscopic level.",
"doi": "10.1117/1.3594785",
"pmcid": "PMC3144972",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2011-07",
"series_number": "7",
"volume": "16",
"issue": "7",
"pages": "Art. No. 076002"
},
{
"id": "authors:r02rb-9rg67",
"collection": "authors",
"collection_id": "r02rb-9rg67",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160829-132036952",
"type": "article",
"title": "Photoacoustic tomography of monkey brain using virtual point ultrasonic transducers",
"author": [
{
"family_name": "Nie",
"given_name": "Liming",
"clpid": "Nie-Liming"
},
{
"family_name": "Guo",
"given_name": "Zijian",
"clpid": "Guo-Zijian"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A photoacoustic tomography system (PAT) using virtual point ultrasonic transducers was developed and applied to image a monkey brain. The custom-built transducers provide a 10-fold greater field-of-view (FOV) than finite-aperture unfocused transducers as well as an improved signal-to-noise ratio (SNR) and reduced artifacts rather than negative-lens transducers. Their tangential resolution, radial resolution, and (SNR) improvements were quantified using tissue phantoms. Our PAT system can achieve high uniformity in both resolution (<1 mm) and SNR (>8) within a large FOV of 6 cm in diameter, even when the imaging objects are enclosed by a monkey skull. The cerebral cortex of a monkey brain was accurately mapped transcranially, through a skull ranging from 2 to 4 mm in thickness. This study demonstrates that PAT can overcome the optical and ultrasound attenuation of a relatively thick skull and can potentially be applied to human neonatal brain imaging.",
"doi": "10.1117/1.3595842",
"pmcid": "PMC3144974",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2011-07",
"series_number": "7",
"volume": "16",
"issue": "7",
"pages": "Art. No. 076005"
},
{
"id": "authors:x4pq3-dke59",
"collection": "authors",
"collection_id": "x4pq3-dke59",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160818-105215538",
"type": "article",
"title": "Label-Free Bond-Selective Imaging by Listening to Vibrationally Excited Molecules",
"author": [
{
"family_name": "Wang",
"given_name": "Han-Wei",
"clpid": "Wang-Han-Wei"
},
{
"family_name": "Chai",
"given_name": "Ning",
"clpid": "Chai-Ning"
},
{
"family_name": "Wang",
"given_name": "Pu",
"clpid": "Wang-Pu"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Dou",
"given_name": "Wei",
"clpid": "Dou-Wei"
},
{
"family_name": "Umulis",
"given_name": "David",
"clpid": "Umulis-D"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Sturek",
"given_name": "Michael",
"clpid": "Sturek-M"
},
{
"family_name": "Lucht",
"given_name": "Robert",
"clpid": "Lucht-R"
},
{
"family_name": "Cheng",
"given_name": "Ji-Xin",
"clpid": "Cheng-Ji-Xin"
}
],
"abstract": "We report the realization of vibrational photoacoustic (VPA) microscopy using optical excitation of molecular overtone vibration and acoustic detection of the resultant pressure transients. Our approach eliminates the tissue scattering problem encountered in near-infrared spectroscopy and enables depth-resolved signal collection. The 2nd overtone of the CH bond stretch around 8300\u2009\u2009cm^(\u22121), where blood interference is minimal, is excited. We demonstrate 3D VPA imaging of lipid-rich atherosclerotic plaques by excitation from the artery lumen, and lipid storage in live Drosophila larvae, with millimeter-scale penetration depth.",
"doi": "10.1103/PhysRevLett.106.238106",
"pmcid": "PMC3398792",
"issn": "0031-9007",
"publisher": "American Physical Society",
"publication": "Physical Review Letters",
"publication_date": "2011-06-10",
"series_number": "23",
"volume": "106",
"issue": "23",
"pages": "Art. No. 238106"
},
{
"id": "authors:rc3at-3z198",
"collection": "authors",
"collection_id": "rc3at-3z198",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160817-140443955",
"type": "article",
"title": "In vivo photoacoustic tomography of mouse cerebral edema induced by cold injury",
"author": [
{
"family_name": "Xu",
"given_name": "Zhun",
"clpid": "Xu-Zhun"
},
{
"family_name": "Zhu",
"given_name": "Quing",
"clpid": "Zhu-Quing"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "For the first time, we have implemented photoacoustic tomography (PAT) to image the water content of an edema in vivo. We produced and imaged a cold-induced cerebral edema transcranially, then obtained blood vessel and water accumulation images at 610 and 975 nm, respectively. We tracked the changes at 12, 24, and 36 h after the cold injury. The blood volume decreased after the cold injury, and the maximum area of edema was observed 24 h after the cold injury. We validated PAT of the water content of the edema through magnetic Resonance Imaging and the water spectrum from the spectrophotometric measurement.",
"doi": "10.1117/1.3584847",
"pmcid": "PMC3124533",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2011-06",
"series_number": "6",
"volume": "16",
"issue": "6",
"pages": "Art. No. 066020"
},
{
"id": "authors:hm1pw-wnd97",
"collection": "authors",
"collection_id": "hm1pw-wnd97",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160614-102345366",
"type": "article",
"title": "Three-dimensional Optical-resolution Photoacoustic Microscopy",
"author": [
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical microscopy, providing valuable insights at the cellular and organelle levels, has been widely recognized as an enabling biomedical technology. As the mainstays of in vivo three-dimensional (3-D) optical microscopy, single-/multi-photon fluorescence microscopy and optical coherence tomography (OCT) have demonstrated their extraordinary sensitivities to fluorescence and optical scattering contrasts, respectively. However, the optical absorption contrast of biological tissues, which encodes essential physiological/pathological information, has not yet been assessable. \nThe emergence of biomedical photoacoustics has led to a new branch of optical microscopy optical-resolution photoacoustic microscopy (OR-PAM), where the optical irradiation is focused to the diffraction limit to achieve cellular1 or even subcellular level lateral resolution. As a valuable complement to existing optical microscopy technologies, OR-PAM brings in at least two novelties. First and most importantly, OR-PAM detects optical absorption contrasts with extraordinary sensitivity (i.e., 100%). Combining OR-PAM with fluorescence microscopy or with optical-scattering-based OCT (or with both) provides comprehensive optical properties of biological tissues. Second, OR-PAM encodes optical absorption into acoustic waves, in contrast to the pure optical processes in fluorescence microscopy and OCT, and provides background-free detection. The acoustic detection in OR-PAM mitigates the impacts of optical scattering on signal degradation and naturally eliminates possible interferences (i.e., crosstalks) between excitation and detection, which is a common problem in fluorescence microscopy due to the overlap between the excitation and fluorescence spectra. \nUnique for optical absorption imaging, OR-PAM has demonstrated broad biomedical applications since its invention, including, but not limited to, neurology, ophthalmology, vascular biology, and dermatology. In this video, we teach the system configuration and alignment of OR-PAM as well as the experimental procedures for in vivo functional microvascular imaging.",
"doi": "10.3791/2729",
"pmcid": "PMC3197122",
"issn": "1940-087X",
"publisher": "JoVE",
"publication": "Journal of Visualized Experiments",
"publication_date": "2011-05-03",
"volume": "51",
"pages": "Art. No. e2729"
},
{
"id": "authors:djcd0-x8f56",
"collection": "authors",
"collection_id": "djcd0-x8f56",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160817-090507356",
"type": "article",
"title": "Conditional HIF-1 induction produces multistage neovascularization with stage-specific sensitivity to VEGFR inhibitors and myeloid cell independence",
"author": [
{
"family_name": "Oladipupo",
"given_name": "Sunday S.",
"orcid": "0000-0001-6555-0693",
"clpid": "Oladipupo-Sunday-S"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Santeford",
"given_name": "Andrea C.",
"clpid": "Santeford-Andrea-C"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Kovalski",
"given_name": "Joanna R.",
"clpid": "Kovalski-Janna-R"
},
{
"family_name": "Shohet",
"given_name": "Ralph V.",
"clpid": "Shohet-Ralph-V"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-Konstantin-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Arbeit",
"given_name": "Jeffrey M.",
"clpid": "Arbeit-J-M"
}
],
"abstract": "Neovascularization is a crucial component of tumor growth and ischemia. Although prior work primarily used disease models, delineation of neovascularization in the absence of disease can reveal intrinsic mechanisms of microvessel regulation amenable to manipulation in illness. We created a conditional model of epithelial HIF-1 induction in adult mice (TetON-HIF-1 mice). Longitudinal photoacoustic microscopy (L-PAM) was coincidentally developed for noninvasive, label-free serial imaging of red blood cell-perfused vasculature in the same mouse for weeks to months. TetON-HIF-1 mice evidenced 3 stages of neovascularization: development, maintenance, and transgene-dependent regression. Regression occurred despite extensive and tight pericyte coverage. L-PAM mapped microvascular architecture and quantified volumetric changes in neocapillary morphogenesis, arteriovenous remodeling, and microvessel regression. Developmental stage endothelial proliferation down-regulation was associated with a DNA damage checkpoint consisting of p53, p21, and endothelial \u03b3-H2AX induction. The neovasculature was temporally responsive to VEGFR2 immuno-blockade, with the developmental stage sensitive, and the maintenance stage resistant, to DC101 treatment. L-PAM analysis also pinpointed microvessels ablated or resistant to VEGFR2 immuno-blockade. HIF-1\u2013recruited myeloid cells did not mediate VEGFR2 inhibitor resistance. Thus, HIF-1 neovascularization in the absence of disease is self-regulated via cell autonomous endothelial checkpoints, and resistant to angiogenesis inhibitors independent of myeloid cells.",
"doi": "10.1182/blood-2010-09-307538",
"pmcid": "PMC3087536",
"issn": "0006-4971",
"publisher": "American Society of Hematology",
"publication": "Blood",
"publication_date": "2011-04-14",
"series_number": "15",
"volume": "117",
"issue": "15",
"pages": "4142-4153"
},
{
"id": "authors:mb7ct-40z61",
"collection": "authors",
"collection_id": "mb7ct-40z61",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160817-085636784",
"type": "article",
"title": "A New Theranostic System Based on Gold Nanocages and Phase-Change Materials with Unique Features for Photoacoustic Imaging and Controlled Release",
"author": [
{
"family_name": "Moon",
"given_name": "Geon Dae",
"clpid": "Moon-Geon-Dae"
},
{
"family_name": "Choi",
"given_name": "Sung-Wook",
"clpid": "Choi-Sung-Wook"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Li",
"given_name": "Weiyang",
"clpid": "Li-Weiyang"
},
{
"family_name": "Cho",
"given_name": "Eun Chul",
"clpid": "Cho-Eun-Chul"
},
{
"family_name": "Jeong",
"given_name": "Unyong",
"clpid": "Jeong-Unyong"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "This communication reports a new theranostic system with a combination of capabilities to both enhance the contrast of photoacoustic (PA) imaging and control the release of a chemical or biological effector by high-intensity focused ultrasound (HIFU). The fabrication of this system simply involves filling the hollow interiors of gold nanocages with a phase-change material (PCM) such as 1-tetradecanol that has a melting point of 38\u221239 \u00b0C. The PCM can be premixed and thus loaded with a dye, as well as other chemical or biological effectors. When exposed to direct heating or HIFU, the PCM will melt and escape from the interiors of nanocages through small pores on the surface, concurrently releasing the encapsulated molecules into the surrounding medium. We can control the release profile by varying the power of HIFU, the duration of exposure to HIFU, or both.",
"doi": "10.1021/ja200894u",
"pmcid": "PMC3073071",
"issn": "0002-7863",
"publisher": "American Chemical Society",
"publication": "Journal of the American Chemical Society",
"publication_date": "2011-04-06",
"series_number": "13",
"volume": "133",
"issue": "13",
"pages": "4762-4765"
},
{
"id": "authors:vne4n-smg52",
"collection": "authors",
"collection_id": "vne4n-smg52",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160829-133426861",
"type": "article",
"title": "Real-time four-dimensional optical-resolution photoacoustic microscopy with Au nanoparticle-assisted subdiffraction-limit resolution",
"author": [
{
"family_name": "Rao",
"given_name": "Bin",
"orcid": "0000-0001-6494-3110",
"clpid": "Rao-Bin"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Danielli",
"given_name": "Amos",
"clpid": "Danielli-A"
},
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic microscopy (PAM) offers label-free, optical absorption contrast. A high-speed, high-resolution PAM system in an inverted microscope configuration with a laser pulse repetition rate of 100,000\u2009Hz and a stationary ultrasonic transducer was built. Four-dimensional in vivo imaging of microcirculation in mouse skin was achieved at 18 three-dimensional volumes per second with repeated two-dimensional (2D) raster scans of 100 by 50 points. The corresponding 2D B-scan (50 A-lines) frame rate was 1800\u2009Hz, and the one-dimensional A-scan rate was 90,000\u2009Hz. The lateral resolution is 0.23\u00b10.03\u2009\u03bcm for Au nanowire imaging, which is 2.0 times below the diffraction limit.",
"doi": "10.1364/OL.36.001137",
"pmcid": "PMC3129741",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2011-04-01",
"series_number": "7",
"volume": "36",
"issue": "7",
"pages": "1137-1139"
},
{
"id": "authors:gygaz-hh777",
"collection": "authors",
"collection_id": "gygaz-hh777",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160822-144415947",
"type": "article",
"title": "Multifocal optical-resolution photoacoustic microscopy in vivo",
"author": [
{
"family_name": "Song",
"given_name": "Liang",
"clpid": "Song-Liang"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Although ultrasound arrays have been exploited in photoacoustic imaging to improve imaging speed, ultrasound-array-based optical-resolution photoacoustic microscopy (OR-PAM) has never been achieved previously to our knowledge. Here we present our development of multifocal OR-PAM using a microlens array for optical illumination and an ultrasound array for photoacoustic detection. Our system is capable of imaging hemoglobin concentration and oxygenation in individual microvessels in vivo at high speed. Compared with a single focus, multiple foci reduce the scanning load and increase the imaging speed significantly. The current multifocal system can acquire 1000\u00d7500\u00d7200 voxels at \u223c10\u2009\u03bcm lateral resolution within 4\u2009min.",
"doi": "10.1364/OL.36.001236",
"pmcid": "PMC3093968",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2011-04-01",
"series_number": "7",
"volume": "36",
"issue": "7",
"pages": "1236-1238"
},
{
"id": "authors:kv15k-6kp12",
"collection": "authors",
"collection_id": "kv15k-6kp12",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160829-145234761",
"type": "article",
"title": "Second-generation optical-resolution photoacoustic microscopy with improved sensitivity and speed",
"author": [
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We developed second-generation (G2) optical-resolution photoacoustic microscopy (OR-PAM). Incorporation of a novel acoustic detection scheme improved upon the sensitivity of our first-generation (G1) system by 18.4\u2009dB, deepening the in vivo tissue penetration to 1.2\u2009mm at 570\u2009nm. Moreover, translating the imaging head instead of the living object accelerated the scanning speed by a factor of 5, widening the field of view within the same acquisition time. Mouse ears, as well as mouse brains with intact craniums, were imaged in vivo in both total concentration and oxygen saturation of hemoglobin.",
"doi": "10.1364/OL.36.001134",
"pmcid": "PMC3076123",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2011-04-01",
"series_number": "7",
"volume": "36",
"issue": "7",
"pages": "1134-1136"
},
{
"id": "authors:2wbpq-8g904",
"collection": "authors",
"collection_id": "2wbpq-8g904",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160817-131445520",
"type": "article",
"title": "In vivo integrated photoacoustic and confocal microscopy of hemoglobin oxygen saturation and oxygen partial pressure",
"author": [
{
"family_name": "Wang",
"given_name": "Yu",
"orcid": "0000-0003-3589-9274",
"clpid": "Wang-Yu"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Zhang",
"given_name": "Yu",
"orcid": "0000-0001-8938-1927",
"clpid": "Zhang-Yu"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We developed dual-modality microscope integrating photoacoustic microscopy (PAM) and fluorescence confocal microscopy (FCM) to noninvasively image hemoglobin oxygen saturation (sO_2) and oxygen partial pressure (pO_2) in vivo in single blood vessels with high spatial resolution. While PAM measures sO_2 by imaging hemoglobin optical absorption at two wavelengths, FCM quantifies pO_2 using phosphorescence quenching. The variations of sO_2 and pO_2 values in multiple orders of vessel branches under hyperoxic (100% oxygen) and normoxic (21% oxygen) conditions correlate well with the oxygen\u2013hemoglobin dissociation curve. In addition, the total concentration of hemoglobin is imaged by PAM at an isosbestic wavelength.",
"doi": "10.1364/OL.36.001029",
"pmcid": "PMC3076119",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2011-04-01",
"series_number": "7",
"volume": "36",
"issue": "7",
"pages": "1029-1031"
},
{
"id": "authors:sy967-vgp61",
"collection": "authors",
"collection_id": "sy967-vgp61",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160615-092457300",
"type": "article",
"title": "Porphysome nanovesicles generated by porphyrin bilayers for use as multimodal biophotonic contrast agents",
"author": [
{
"family_name": "Lovell",
"given_name": "Jonathan F.",
"clpid": "Lovell-J-F"
},
{
"family_name": "Jin",
"given_name": "Cheng S.",
"clpid": "Jin-Cheng-S"
},
{
"family_name": "Huynh",
"given_name": "Elizabeth",
"clpid": "Huynh-Elizabeth"
},
{
"family_name": "Jin",
"given_name": "Honglin",
"clpid": "Jin-Honglin"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Rubinstein",
"given_name": "John L.",
"orcid": "0000-0003-1274-6785",
"clpid": "Rubinstein-J-L"
},
{
"family_name": "Chan",
"given_name": "Warren C. W.",
"clpid": "Chan-Warren-C-W"
},
{
"family_name": "Cao",
"given_name": "Weiguo",
"clpid": "Cao-Weiguo"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Zheng",
"given_name": "Gang",
"clpid": "Zheng-Gang"
}
],
"abstract": "Optically active nanomaterials promise to advance a range of biophotonic techniques through nanoscale optical effects and integration of multiple imaging and therapeutic modalities. Here, we report the development of porphysomes; nanovesicles formed from self-assembled porphyrin bilayers that generated large, tunable extinction coefficients, structure-dependent fluorescence self-quenching and unique photothermal and photoacoustic properties. Porphysomes enabled the sensitive visualization of lymphatic systems using photoacoustic tomography. Near-infrared fluorescence generation could be restored on dissociation, creating opportunities for low-background fluorescence imaging. As a result of their organic nature, porphysomes were enzymatically biodegradable and induced minimal acute toxicity in mice with intravenous doses of 1,000\u2009mg\u2009kg^(\u22121). In a similar manner to liposomes, the large aqueous core of porphysomes could be passively or actively loaded. Following systemic administration, porphysomes accumulated in tumours of xenograft-bearing mice and laser irradiation induced photothermal tumour ablation. The optical properties and biocompatibility of porphysomes demonstrate the multimodal potential of organic nanoparticles for biophotonic imaging and therapy.",
"doi": "10.1038/NMAT2986",
"issn": "1476-1122",
"publisher": "Nature Publishing Group",
"publication": "Nature Materials",
"publication_date": "2011-04",
"series_number": "4",
"volume": "10",
"issue": "4",
"pages": "324-332"
},
{
"id": "authors:4qbhk-2zk38",
"collection": "authors",
"collection_id": "4qbhk-2zk38",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160817-104828903",
"type": "article",
"title": "High-Transmission-Efficiency and Side-Viewing Micro OIDRS Probe for Fast and Minimally Invasive Tumor Margin Detection",
"author": [
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Chang",
"given_name": "Cheng-Chung",
"clpid": "Chang-Cheng-Chung"
},
{
"family_name": "Yapici",
"given_name": "Murat Kaya",
"clpid": "Yapici-M-K"
},
{
"family_name": "Zou",
"given_name": "Jun",
"orcid": "0000-0002-9543-6135",
"clpid": "Zou-Jun"
},
{
"family_name": "Banerjee",
"given_name": "Bhaskar",
"clpid": "Banerjee-B"
},
{
"family_name": "Kuczynski",
"given_name": "John",
"clpid": "Kuczynski-J"
},
{
"family_name": "Ong",
"given_name": "Evan S.",
"clpid": "Ong-Evan-S"
},
{
"family_name": "Marner",
"given_name": "Erin S.",
"clpid": "Marner-E-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The determination of a cancer free margin I organ is a difficult and time consuming process, with an unmet need for rapid determination of tumor margin at surgery. In this paper, we report the design, fabrication, and testing of a novel miniaturized optical sensor probe with \"side-viewing\" capability. Its unprecedented small size, unique \"side-viewing\" capability, and high optical transmission efficiency enable the agile maneuvering and efficient data collection even in the narrow cavities inside the human body. The sensor probe consists of four micromachined substrates with optical fibers for oblique light incidence and collection of spatially resolved diffuse reflectance from the contacted tissues. The optical sensor probe has been used to conduct the oblique incidence diffuse reflectance spectroscopy (OIDRS) on a human pancreatic specimen. Based on the measurement results, the margin of the malignant tumor has been successfully determined optically, which matches well with the histological results.",
"doi": "10.1109/JSEN.2010.2076279",
"pmcid": "PMC3072170",
"issn": "1530-437X",
"publisher": "IEEE",
"publication": "IEEE Sensors Journal",
"publication_date": "2011-04",
"series_number": "4",
"volume": "11",
"issue": "4",
"pages": "891-896"
},
{
"id": "authors:eyked-y4185",
"collection": "authors",
"collection_id": "eyked-y4185",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160829-131342093",
"type": "article",
"title": "Photoacoustic tomography of foreign bodies in soft biological tissue",
"author": [
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Pramanik",
"given_name": "Manojit",
"clpid": "Pramanik-M"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In detecting small foreign bodies in soft biological tissue, ultrasound imaging suffers from poor sensitivity (52.6%) and specificity (47.2%). Hence, alternative imaging methods are needed. Photoacoustic (PA) imaging takes advantage of strong optical absorption contrast and high ultrasonic resolution. A PA imaging system is employed to detect foreign bodies in biological tissues. To achieve deep penetration, we use near-infrared light ranging from 750 to 800 nm and a 5-MHz spherically focused ultrasonic transducer. PA images were obtained from various targets including glass, wood, cloth, plastic, and metal embedded more than 1 cm deep in chicken tissue. The locations and sizes of the targets from the PA images agreed well with those of the actual samples. Spectroscopic PA imaging was also performed on the objects. These results suggest that PA imaging can potentially be a useful intraoperative imaging tool to identify foreign bodies.",
"doi": "10.1117/1.3569613",
"pmcid": "PMC3094467",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2011-04",
"series_number": "4",
"volume": "16",
"issue": "4",
"pages": "Art. No. 046017"
},
{
"id": "authors:9cmnk-8gk93",
"collection": "authors",
"collection_id": "9cmnk-8gk93",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160817-103755317",
"type": "article",
"title": "Gold nanocages covered with thermally-responsive polymers for controlled release by high-intensity focused ultrasound",
"author": [
{
"family_name": "Li",
"given_name": "Weiyang",
"clpid": "Li-Weiyang"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Sun",
"given_name": "Guorong",
"clpid": "Sun-Guorong"
},
{
"family_name": "Zhang",
"given_name": "Yu",
"orcid": "0000-0001-8938-1927",
"clpid": "Zhang-Yu"
},
{
"family_name": "Deng",
"given_name": "Rui",
"clpid": "Deng-Rui"
},
{
"family_name": "Yang",
"given_name": "Miaoxin",
"clpid": "Yang-Miaoxin"
},
{
"family_name": "Chen",
"given_name": "Jingyi",
"clpid": "Chen-Jingyi"
},
{
"family_name": "Achilefu",
"given_name": "Samuel",
"clpid": "Achilefu-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "This paper describes the use of Au nanocages covered with smart, thermally-responsive polymers for controlled release with high-intensity focused ultrasound (HIFU). HIFU is a highly precise medical procedure that uses focused ultrasound to heat and destroy pathogenic tissue rapidly and locally in a non-invasive or minimally invasive manner. The released dosage could be remotely controlled by manipulating the power of HIFU and/or the duration of exposure. We demonstrated localized release within the focal volume of HIFU by using gelatin phantom samples containing dye-loaded Au nanocages. By placing chicken breast tissues on top of the phantoms, we further demonstrated the feasibility of this system for controlled release at depths up to 30 mm. Because it can penetrate more deeply into soft tissues than near-infrared light, HIFU is a potentially more effective external stimulus for rapid, on-demand drug release.",
"doi": "10.1039/c0nr00932f",
"pmcid": "PMC3079502",
"issn": "2040-3364",
"publisher": "Royal Society of Chemistry",
"publication": "Nanoscale",
"publication_date": "2011-04",
"series_number": "4",
"volume": "3",
"issue": "4",
"pages": "1724-1730"
},
{
"id": "authors:49b09-13411",
"collection": "authors",
"collection_id": "49b09-13411",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160706-154834170",
"type": "article",
"title": "In vivo photoacoustic mapping of lymphatic systems with plasmon-resonant nanostars",
"author": [
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Song",
"given_name": "Hyon-Min",
"clpid": "Song-Hyon-Min"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wei",
"given_name": "Alexander",
"clpid": "Wei-Alexander"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Plasmon-resonant nanostars (NSTs) provide excellent contrast enhancement for photoacoustic tomography. The high photoacoustic sensitivity of NSTs at near-infrared wavelengths enables their in vivo detection in rat sentinel lymph nodes and vessels, with direct application toward lymphangiography.",
"doi": "10.1039/c0jm04194g",
"pmcid": "PMC3110006",
"issn": "0959-9428",
"publisher": "Royal Society of Chemistry",
"publication": "Journal of Materials Chemistry",
"publication_date": "2011-03-07",
"series_number": "9",
"volume": "21",
"issue": "9",
"pages": "2841-2844"
},
{
"id": "authors:y287a-tz178",
"collection": "authors",
"collection_id": "y287a-tz178",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160830-074437385",
"type": "article",
"title": "Single-wavelength functional photoacoustic microscopy in biological tissue",
"author": [
{
"family_name": "Danielli",
"given_name": "Amos",
"clpid": "Danielli-A"
},
{
"family_name": "Favazza",
"given_name": "Christopher P.",
"clpid": "Favazza-C-P"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Recently, we developed a reflection-mode relaxation photoacoustic microscope, based on saturation intensity, to measure picosecond relaxation times using a nanosecond laser. Here, using the different relaxation times of oxygenated and deoxygenated hemoglobin molecules, both possessing extremely low fluorescence quantum yields, the oxygen saturation was quantified in vivo with single-wavelength photoacoustic microscopy. All previous functional photoacoustic microscopy measurements required imaging with multiple-laser-wavelength measurements to quantify oxygen saturation. Eliminating the need for multiwavelength measurements removes the influence of spectral properties on oxygenation calculations and improves the portability and cost-effectiveness of functional or molecular photoacoustic microscopy.",
"doi": "10.1364/OL.36.000769",
"pmcid": "PMC3074491",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2011-03-01",
"series_number": "5",
"volume": "36",
"issue": "5",
"pages": "769-771"
},
{
"id": "authors:b9cf2-7t021",
"collection": "authors",
"collection_id": "b9cf2-7t021",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160819-135228667",
"type": "article",
"title": "Molecular photoacoustic imaging of angiogenesis with integrin-targeted gold nanobeacons",
"author": [
{
"family_name": "Pan",
"given_name": "Dipanjan",
"clpid": "Pan-Dipanjan"
},
{
"family_name": "Pramanik",
"given_name": "Manojit",
"clpid": "Pramanik-M"
},
{
"family_name": "Senpan",
"given_name": "Angana",
"clpid": "Senpan-A"
},
{
"family_name": "Allen",
"given_name": "John S.",
"clpid": "Allen-J-S"
},
{
"family_name": "Zhang",
"given_name": "Huiying",
"clpid": "Zhang-Huiying"
},
{
"family_name": "Wickline",
"given_name": "Samuel A.",
"clpid": "Wickline-S-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Lanza",
"given_name": "Gregory M.",
"clpid": "Lanza-G-M"
}
],
"abstract": "Photoacoustic tomography (PAT) combines optical and acoustic imaging to generate high-resolution images of microvasculature. Inherent sensitivity to hemoglobin permits PAT to image blood vessels but precludes discriminating neovascular from maturing microvasculature. \u0391_v\u03b2_3-Gold nanobeacons (\u03b1_v\u03b2_3-GNBs) for neovascular molecular PAT were developed, characterized, and demonstrated in vivo using a mouse Matrigel-plug model of angiogenesis. PAT results were microscopically corroborated with fluorescent \u03b1_v\u03b2_3-GNB localization and supporting immunohistology in Rag1^(tm1Mom) Tg(Tie-2-lacZ)182-Sato mice. \u0391_v\u03b2_3-GNBs (154 nm) had 10-fold greater contrast than blood on an equivolume basis when imaged at 740 nm to 810 nm in blood. The lowest detectable concentration in buffer was 290 nM at 780 nm. Noninvasive PAT of angiogenesis using a 10-MHz ultrasound receiver with \u03b1_v\u03b2_3-GNBs produced a 600% increase in signal in a Matrigel-plug mouse model relative to the inherent hemoglobin contrast pretreatment. In addition to increasing the contrast of neovessels detected at baseline, \u03b1_v\u03b2_3-GNBs allowed visualization of numerous angiogenic sprouts and bridges that were undetectable before contrast injection. Competitive inhibition of \u03b1_v\u03b2_3-GNBs with \u03b1_v\u03b2_3-NBs (no gold particles) almost completely blocked contrast enhancement to pretreatment levels, similar to the signal from animals receiving saline only. Consistent with other studies, nontargeted GNBs passively accumulated in the tortuous neovascular but provided less than half of the contrast enhancement of the targeted agent. Microscopic studies revealed that the vascular constrained, rhodamine-labeled \u03b1_v\u03b2_3-GNBs homed specifically to immature neovasculature (PECAM+, Tie-2\u2212) along the immediate tumor periphery, but not to nearby mature microvasculature (PECAM+, Tie-2+). The combination of PAT and \u03b1_v\u03b2_3-GNBs offered sensitive and specific discrimination and quantification of angiogenesis in vivo, which may be clinically applicable to a variety of highly prevalent diseases, including cancer and cardiovascular disease.\u2014Pan, D., Pramanik, M., Senpan, A., Allen, J. S., Zhang, H., Wickline, S. A., Wang, L. V., Lanza, G. M. Molecular photoacoustic imaging of angiogenesis with integrin-targeted gold nanobeacons.",
"doi": "10.1096/fj.10-171728",
"pmcid": "PMC3042842",
"issn": "0892-6638",
"publisher": "Federation of American Societies for Experimental Biology",
"publication": "FASEB Journal",
"publication_date": "2011-03",
"series_number": "3",
"volume": "25",
"issue": "3",
"pages": "875-882"
},
{
"id": "authors:r9mxj-sdp55",
"collection": "authors",
"collection_id": "r9mxj-sdp55",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-074743692",
"type": "article",
"title": "Time-reversed ultrasonically encoded optical focusing into scattering media",
"author": [
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Liu",
"given_name": "Honglin",
"orcid": "0000-0003-2473-9056",
"clpid": "Liu-Honglin"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Light focusing plays a central role in biomedical imaging, manipulation and therapy. In scattering media, direct light focusing becomes infeasible beyond one transport mean free path. All previous methods used to overcome this diffusion limit lack a practical internal 'guide star'. Here, we propose and experimentally validate a novel concept called time-reversed ultrasonically encoded (TRUE) optical focusing to deliver light into any dynamically defined location inside a scattering medium. First, diffused coherent light is encoded by a focused ultrasonic wave to provide a virtual internal guide star. Only the encoded light is time-reversed and transmitted back to the ultrasonic focus. The time-reversed ultrasonically encoded optical focus\u2014defined by the ultrasonic wave\u2014is unaffected by multiple scattering of light. Such focusing is particularly desirable in biological tissue, where ultrasonic scattering is ~1,000 times weaker than optical scattering. Various fields, including biomedical and colloidal optics, can benefit from TRUE optical focusing.",
"doi": "10.1038/NPHOTON.2010.306",
"pmcid": "PMC3083021",
"issn": "1749-4885",
"publisher": "Nature Publishing Group",
"publication": "Nature Photonics",
"publication_date": "2011-03",
"series_number": "3",
"volume": "5",
"issue": "3",
"pages": "154-157"
},
{
"id": "authors:883pq-9te27",
"collection": "authors",
"collection_id": "883pq-9te27",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160819-123246119",
"type": "article",
"title": "In-vivo characterization of optical properties of pigmented skin lesions including melanoma using oblique incidence diffuse reflectance spectrometry",
"author": [
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Smith",
"given_name": "Elizabeth B.",
"clpid": "Smith-E-B"
},
{
"family_name": "Zou",
"given_name": "Jun",
"orcid": "0000-0002-9543-6135",
"clpid": "Zou-Jun"
},
{
"family_name": "Duvic",
"given_name": "Madeleine",
"clpid": "Duvic-M"
},
{
"family_name": "Prieto",
"given_name": "Victor",
"clpid": "Prieto-V-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In this letter, we report the first use of oblique incidence diffuse reflectance spectrometry to conduct in-vivo measurements of optical properties of three different types of pigmented skin lesions, including melanoma, dysplastic, and common nevi. Both absorption and reduced scattering coefficient spectra were estimated from the spatially resolved diffuse reflectance within the wavelength range of 455\u2013765 nm for 144 pigmented skin lesions including 16 melanomas. The absorption and reduced scattering spectra were found to change with the malignancy of the skin lesions, which were generally higher for the malignant cases than the benign ones. Based on the measurement results, the physiological origin leading to the change of the absorption and scattering properties is also discussed.",
"doi": "10.1117/1.3536509",
"pmcid": "PMC3061328",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2011-02",
"series_number": "2",
"volume": "16",
"issue": "2",
"pages": "Art. No. 020501"
},
{
"id": "authors:84an3-07j54",
"collection": "authors",
"collection_id": "84an3-07j54",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160817-130233256",
"type": "article",
"title": "In vivo functional photoacoustic microscopy of cutaneous microvasculature in human skin",
"author": [
{
"family_name": "Favazza",
"given_name": "Christopher P.",
"clpid": "Favazza-C-P"
},
{
"family_name": "Cornelius",
"given_name": "Lynn A.",
"clpid": "Cornelius-L-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Microcirculation is an important component of the cardiovascular system and can be used to assess systemic cardiovascular health. Numerous studies have investigated cutaneous microcirculation as an indicator of cardiovascular related diseases. Such research has shown promising results; however, there are many limitations regarding the employed measurement techniques, such as poor depth and spatial resolution and measurement versatility. Here we show the results of functional cutaneous microvascular experiments measured with photoacoustic microscopy, which provides high spatial resolution and multiparameter measurements. In a set of experiments, microvascular networks located in the palms of volunteers were perturbed by periodic ischemic events, and the subsequent hemodynamic response to the stimulus was recorded. Results indicate that during periods of arterial occlusion, the relative oxygen saturation of the capillary vessels decreased below resting levels, and temporarily increased above resting levels immediately following the occlusion. Furthermore, a hyperemic reaction to the occlusions was measured, and the observation agreed well with similar measurements using more conventional imaging techniques. Due to its exceptional capability to functionally image vascular networks with high spatial resolution, photoacoustic microscopy could be a beneficial biomedical tool to assess microvascular functioning and applied to patients with diseases that affect cardiovascular health.",
"doi": "10.1117/1.3536522",
"pmcid": "PMC3056315",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2011-02",
"series_number": "2",
"volume": "16",
"issue": "2",
"pages": "Art. No. 026004"
},
{
"id": "authors:5e7fh-gpq32",
"collection": "authors",
"collection_id": "5e7fh-gpq32",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160822-160844254",
"type": "article",
"title": "Noninvasive Photoacoustic and Fluorescence Sentinel Lymph Node Identification using Dye-Loaded Perfluorocarbon Nanoparticles",
"author": [
{
"family_name": "Akers",
"given_name": "Walter J.",
"clpid": "Akers-W-J"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Berezin",
"given_name": "Mikhail",
"clpid": "Berezin-M"
},
{
"family_name": "Guo",
"given_name": "Kevin",
"clpid": "Guo-Kevin"
},
{
"family_name": "Fuhrhop",
"given_name": "Ralph",
"clpid": "Fuhrhop-R"
},
{
"family_name": "Lanza",
"given_name": "Gregory M.",
"clpid": "Lanza-G-M"
},
{
"family_name": "Fischer",
"given_name": "Georg M.",
"clpid": "Fischer-G-M"
},
{
"family_name": "Daltrozzo",
"given_name": "Ewald",
"clpid": "Daltrozzo-E"
},
{
"family_name": "Zumbusch",
"given_name": "Andreas",
"clpid": "Zumbusch-A"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Achilefu",
"given_name": "Samuel",
"clpid": "Achilefu-S"
}
],
"abstract": "The contrast mechanisms used for photoacoustic tomography (PAT) and fluorescence imaging differ in subtle, but significant, ways. The design of contrast agents for each or both modalities requires an understanding of the spectral characteristics as well as intra- and intermolecular interactions that occur during formulation. We found that fluorescence quenching that occurs in the formulation of near-infrared (NIR) fluorescent dyes in nanoparticles results in enhanced contrast for PAT. The ability of the new PAT method to utilize strongly absorbing chromophores for signal generation allowed us to convert a highly fluorescent dye into an exceptionally high PA contrast material. Spectroscopic characterization of the developed NIR dye-loaded perfluorocarbon-based nanoparticles for combined fluorescence and PA imaging revealed distinct dye-dependent photophysical behavior. We demonstrate that the enhanced contrast allows detection of regional lymph nodes of rats in vivo with time-domain optical and photoacoustic imaging methods. The results further show that the use of fluorescence lifetime imaging, which is less dependent on fluorescence intensity, provides a strategic approach to bridge the disparate contrast reporting mechanisms of fluorescence and PA imaging methods.",
"doi": "10.1021/nn102274q",
"pmcid": "PMC3026895",
"issn": "1936-0851",
"publisher": "American Chemical Society",
"publication": "ACS Nano",
"publication_date": "2011-01-25",
"series_number": "1",
"volume": "5",
"issue": "1",
"pages": "173-182"
},
{
"id": "authors:j2w0c-49768",
"collection": "authors",
"collection_id": "j2w0c-49768",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160817-093425724",
"type": "article",
"title": "Fast voice-coil scanning optical-resolution photoacoustic microscopy",
"author": [
{
"family_name": "Wang",
"given_name": "Lidai",
"clpid": "Wang-Lidai"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Rao",
"given_name": "Bin",
"orcid": "0000-0001-6494-3110",
"clpid": "Rao-Bin"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We developed a photoacoustic imaging system that has real-time imaging capability with optical resolution. The imaging system is capable of scanning at 20\u2009Hz over a 9\u2009mm range and up to 40\u2009Hz over a 1\u2009mm scanning range. A focused laser beam provides a lateral resolution of 3.4\u2009\u03bcm as measured in an optically nonscattering medium. Flows of micrometer-sized carbon particles or whole blood in a silicone tube and individual red blood cells (RBCs) in mouse ear capillaries were also imaged in real time, demonstrating the capability to image highly dynamic processes in vivo at a micrometer-scale resolution.",
"doi": "10.1364/OL.36.000139",
"pmcid": "PMC3086411",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2011-01-15",
"series_number": "2",
"volume": "36",
"issue": "2",
"pages": "139-141"
},
{
"id": "authors:bmdpc-wzz33",
"collection": "authors",
"collection_id": "bmdpc-wzz33",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160817-104516558",
"type": "article",
"title": "Gold nanostructures: a class of multifunctional materials for biomedical applications",
"author": [
{
"family_name": "Cobley",
"given_name": "Claire M.",
"clpid": "Cobley-C-M"
},
{
"family_name": "Chen",
"given_name": "Jingyi",
"clpid": "Chen-Jingyi"
},
{
"family_name": "Cho",
"given_name": "Eun Chul",
"clpid": "Cho-Eun-Chul"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "Gold nanostructures have proven to be a versatile platform for a broad range of biomedical applications, with potential use in numerous areas including: diagnostics and sensing, in vitro and in vivo imaging, and therapeutic techniques. These applications are possible because of the highly favorable properties of gold nanostructures, many of which can be tailored for specific applications. In the first part of this tutorial review, we will discuss the most critical properties of gold nanostructures for biomedical applications: surface chemistry, localized surface plasmon resonance (LSPR), and morphology. In the second part of the review, we will discuss how these properties can be harnessed for a selection of biomedical applications, aiming to give the reader an overview of general strategies as well as highlight some recent advances in this field.",
"doi": "10.1039/b821763g",
"issn": "0306-0012",
"publisher": "Royal Society of Chemistry",
"publication": "Chemical Society Reviews",
"publication_date": "2011-01-01",
"series_number": "1",
"volume": "40",
"issue": "1",
"pages": "44-56"
},
{
"id": "authors:w8b64-sww81",
"collection": "authors",
"collection_id": "w8b64-sww81",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160817-095425102",
"type": "article",
"title": "Fiber-laser-based photoacoustic microscopy and melanoma cell detection",
"author": [
{
"family_name": "Wang",
"given_name": "Yu",
"orcid": "0000-0003-3589-9274",
"clpid": "Wang-Yu"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Zhang",
"given_name": "Yu",
"orcid": "0000-0001-8938-1927",
"clpid": "Zhang-Yu"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Yang",
"given_name": "Lihmei",
"clpid": "Yang-Lihmei"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
},
{
"family_name": "Liu",
"given_name": "Jian",
"orcid": "0000-0001-8552-1400",
"clpid": "Liu-Jian"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "For broad applications in biomedical research involving functional dynamics and clinical studies, a photoacoustic microscopy system should be compact, stable, and fast. In this work, we use a fiber laser as the photoacoustic irradiation source to meet these goals. The laser system measures 45\u00d756\u00d713 cm^3. The stability of the laser is attributed to the intrinsic optical fiber-based light amplification and output coupling. Its 50-kHz pulse repetition rate enables fast scanning or extensive signal averaging. At the laser wavelength of 1064 nm, the photoacoustic microscope still has enough sensitivity to image small blood vessels while providing high optical absorption contrast between melanin and hemoglobin. Label-free melanoma cells in flowing bovine blood are imaged in vitro, yielding measurements of both cell size and flow speed.",
"doi": "10.1117/1.3525643",
"pmcid": "PMC3033874",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2011-01",
"series_number": "1",
"volume": "16",
"issue": "1",
"pages": "Art. No. 011014"
},
{
"id": "authors:6hyj5-4cb10",
"collection": "authors",
"collection_id": "6hyj5-4cb10",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160817-135251277",
"type": "article",
"title": "In vivo photoacoustic microscopy of human cutaneous microvasculature and a nevus",
"author": [
{
"family_name": "Favazza",
"given_name": "Christopher P.",
"clpid": "Favazza-C-P"
},
{
"family_name": "Jassim",
"given_name": "Omar",
"clpid": "Jassim-O"
},
{
"family_name": "Cornelius",
"given_name": "Lynn A.",
"clpid": "Cornelius-L-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In several human volunteers, photoacoustic microscopy (PAM) has been utilized for noninvasive cutaneous imaging of the skin microvasculature and a melanocytic nevus. Microvascular networks in both acral and nonacral skin were imaged, and multiple features within the skin have been identified, including the stratum corneum, epidermal-dermal junction, and subpapillary vascular plexus. Several vascular and structural differences between acral and nonacral skin were also observed in the photoacoustic images. In addition, a nevus was photoacoustically imaged, excised, and histologically analyzed. The photoacoustic images allowed for in vivo measurement of tumor thickness, depth, and microvasculature-values confirmed by histologic examination. The presented images demonstrate the potential of PAM to aid in the study and evaluation of cutaneous microcirculation and analysis of pigmented lesions. Through its ability to three-dimensionally image the structure and function of the microvasculature and pigmented lesions, PAM can have a clinical impact in diagnosis and assessment of systemic diseases that affect the microvasculature such as diabetes and cardiovascular disease, cutaneous malignancies such as melanoma, and potentially other skin disorders.",
"doi": "10.1117/1.3528661",
"pmcid": "PMC3055592",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2011-01",
"series_number": "1",
"volume": "16",
"issue": "1",
"pages": "Art. No. 016015"
},
{
"id": "authors:crtdd-cg791",
"collection": "authors",
"collection_id": "crtdd-cg791",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160830-092531683",
"type": "article",
"title": "In vivo label-free photoacoustic microscopy of cell nuclei by excitation of DNA and RNA",
"author": [
{
"family_name": "Yao",
"given_name": "Da-Kang",
"clpid": "Yao-Da-Kang"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Shung",
"given_name": "Kirk K.",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Imaging of cell nuclei plays a critical role in cancer diagnosis and prognosis. To image noninvasively cell nuclei in vivo without staining, we developed UV photoacoustic microscopy (UV-PAM), in which 266nm wavelength UV light excites unlabeled DNA and RNA in cell nuclei to produce photoacoustic waves. We applied UV-PAM to ex vivo imaging of cell nuclei in a mouse lip and a mouse small intestine and to in vivo imaging of the cell nuclei in the mouse skin. The UV-PAM images of unstained cell nuclei match the optical micrographs of the histologically stained cell nuclei. Given intrinsic optical contrast and high spatial resolution, in vivo label-free UV-PAM has potential for unique biological and clinical application.",
"doi": "10.1364/OL.35.004139",
"pmcid": "PMC3048585",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2010-12-15",
"series_number": "24",
"volume": "35",
"issue": "24",
"pages": "4139-4141"
},
{
"id": "authors:8hxpw-fea45",
"collection": "authors",
"collection_id": "8hxpw-fea45",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160701-130302347",
"type": "article",
"title": "A Facile Synthesis of Novel Self-Assembled Gold Nanorods Designed for Near-Infrared Imaging",
"author": [
{
"family_name": "Pan",
"given_name": "Dipanjan",
"clpid": "Pan-Dipanjan"
},
{
"family_name": "Pramanik",
"given_name": "Manojit",
"clpid": "Pramanik-M"
},
{
"family_name": "Senpan",
"given_name": "Angana",
"clpid": "Senpan-A"
},
{
"family_name": "Wickline",
"given_name": "Samuel A.",
"clpid": "Wickline-S-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Lanza",
"given_name": "Gregory M.",
"clpid": "Lanza-G-M"
}
],
"abstract": "Molecular imaging techniques now allow recognition of early biochemical, physiological, and anatomical changes before manifestation of gross pathological changes. Photoacoustic imaging represents a novel non-ionizing detection technique that combines the advantages of optical and ultrasound imaging. Noninvasive photoacoustic tomography (PAT) imaging in combination with nanoparticle-based contrast agents show promise in improved detection and diagnosis of cardiovascular and cancer related diseases. In this report, a novel strategy is introduced to achieve self-assembled colloidal gold nanorods, which are constrained to the vasculature. Gold nanorods (2\u20134 nm) were incorporated into the core of self-assembled lipid-encapsulated nanoparticles (sGNR) (\u223c130 nm), providing more than hundreds of gold atoms per nanoparticle of 20% colloid suspension. The physico-chemical characterization in solution and anhydrous state with analytical techniques demonstrated that the particles were spherical and highly mono dispersed. In addition to the synthesis and characterization, sensitive near-infrared photoacoustic detection was impressively demonstrated in vitro.",
"doi": "10.1166/jnn.2010.3034",
"pmcid": "PMC3096062",
"issn": "1533-4880",
"publisher": "American Scientific Publishers",
"publication": "Journal of Nanoscience and Nanotechnology",
"publication_date": "2010-12",
"series_number": "12",
"volume": "10",
"issue": "12",
"pages": "8118-8123"
},
{
"id": "authors:asdmk-0nn13",
"collection": "authors",
"collection_id": "asdmk-0nn13",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160708-095400051",
"type": "article",
"title": "Gold Nanocages: A Novel Class of Multifunctional Nanomaterials for Theranostic Applications",
"author": [
{
"family_name": "Chen",
"given_name": "Jingyi",
"clpid": "Chen-Jingyi"
},
{
"family_name": "Yang",
"given_name": "Miaoxin",
"clpid": "Yang-Miaoxin"
},
{
"family_name": "Zhang",
"given_name": "Qiang",
"orcid": "0000-0002-8376-131X",
"clpid": "Zhang-Qiang"
},
{
"family_name": "Cho",
"given_name": "Eun Chul",
"clpid": "Cho-Eun-Chul"
},
{
"family_name": "Cobley",
"given_name": "Claire M.",
"clpid": "Cobley-C-M"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Glaus",
"given_name": "Charles",
"clpid": "Glaus-C"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Welch",
"given_name": "Michael J.",
"clpid": "Welch-M-J"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "Gold nanocages represent a novel class of nanostructures, well-suited for biomedical applications. They can be readily prepared via the galvanic replacement reaction between silver nanocubes and chloroauric acid. Their optical resonance peaks can be easily and precisely tuned to the near-infrared region from 650\u2013900 nm, the transparent window for blood and soft tissue. Furthermore, their surface can be conveniently conjugated with various ligands for targeting cancer. In this feature article, we highlight recent advances in the large-scale synthesis of gold nanocages and their applications in cancer diagnosis and treatment. Specifically, we have scaled up the production of gold nanocages for in vivo studies and evaluated their tumor targeting capabilities. We have also demonstrated their use as contrast agents for photoacoustic tumor imaging and the mapping of sentinel lymph node, as photothermal transducers for cancer treatment, and as smart carriers for controlled release with a near-infrared laser.",
"doi": "10.1002/adfm.201001329",
"issn": "1616-301X",
"publisher": "Wiley",
"publication": "Advanced Functional Materials",
"publication_date": "2010-11-09",
"series_number": "21",
"volume": "20",
"issue": "21",
"pages": "3684-3694"
},
{
"id": "authors:0rk8f-88b91",
"collection": "authors",
"collection_id": "0rk8f-88b91",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160706-133413856",
"type": "article",
"title": "Chronic label-free volumetric photoacoustic microscopy of melanoma cells in three-dimensional porous scaffolds",
"author": [
{
"family_name": "Zhang",
"given_name": "Yu",
"orcid": "0000-0001-8938-1927",
"clpid": "Zhang-Yu"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Choi",
"given_name": "Sung-Wook",
"clpid": "Choi-Sung-Wook"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "Visualizing cells in three-dimensional (3D) scaffolds has been one of the major challenges in tissue engineering. Most current imaging modalities either suffer from poor penetration depth or require exogenous contrast agents. Here, we demonstrate photoacoustic microscopy (PAM) of the spatial distribution and temporal proliferation of cells inside three-dimensional porous scaffolds with thicknesses over 1 mm. Specifically, we evaluated the effects of seeding and culture methods on the spatial distribution of melanoma cells. Spatial distribution of the cells in the scaffold was well-resolved in PAM images. Moreover, the number of cells in the scaffold was quantitatively measured from the as-obtained volumetric information. The cell proliferation profile obtained from PAM correlated well with what was obtained using the traditional 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.",
"doi": "10.1016/j.biomaterials.2010.07.089",
"pmcid": "PMC2949455",
"issn": "0142-9612",
"publisher": "Elsevier",
"publication": "Biomaterials",
"publication_date": "2010-11",
"series_number": "33",
"volume": "31",
"issue": "33",
"pages": "8651-8658"
},
{
"id": "authors:k7ve6-2vt85",
"collection": "authors",
"collection_id": "k7ve6-2vt85",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160920-084957348",
"type": "article",
"title": "Spectral hole burning for ultrasound-modulated optical tomography of thick tissue",
"author": [
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Kothapalli",
"given_name": "Sri-Rajasekhar",
"clpid": "Kothapalli-S-R"
},
{
"family_name": "Liu",
"given_name": "Honglin",
"orcid": "0000-0003-2473-9056",
"clpid": "Liu-Honglin"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We apply spectral hole burning (SHB)-aided detection in ultrasound-modulated optical tomography (UOT) to image optical heterogeneities in thick tissue-mimicking phantom samples and chicken breast tissue. The efficiency of SHB is improved by using a Tm^(3+):YAG crystal of higher doping concentration (2.0-atomic%) and a double-pass pumping configuration, in which the pump beam is transmitted through the crystal twice to burn a deeper spectral hole with the available optical intensity. With the improved SHB-UOT system, we image absorbing, scattering, and phase objects that are embedded in the middle plane of a 30-mm-thick phantom sample. The imaging resolution was 0.5 mm in the lateral direction, as defined by the focal width of the ultrasonic transducer, and 1.5 mm in the axial direction, as determined by the ultrasonic burst length. We also image two absorbing objects embedded in a 32-mm-thick chicken breast sample. The results suggest that the improved SHB-UOT system is one step closer to the practical optical imaging application in biological and clinical studies.",
"doi": "10.1117/1.3505486",
"pmcid": "PMC3017574",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2010-11",
"series_number": "6",
"volume": "15",
"issue": "6",
"pages": "Art. No. 066018"
},
{
"id": "authors:1tr6j-v6017",
"collection": "authors",
"collection_id": "1tr6j-v6017",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160706-124901577",
"type": "article",
"title": "Picosecond absorption relaxation measured with nanosecond laser photoacoustics",
"author": [
{
"family_name": "Danielli",
"given_name": "Amos",
"clpid": "Danielli-A"
},
{
"family_name": "Favazza",
"given_name": "Christopher P.",
"clpid": "Favazza-C-P"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Picosecond absorption relaxation\u2014central to many disciplines\u2014is typically measured by ultrafast (femtosecond or picosecond) pump-probe techniques, which however are restricted to optically thin and weakly scattering materials or require artificial sample preparation. Here, we developed a reflection-mode relaxation photoacoustic microscope based on a nanosecond laser and measured picosecond absorptionrelaxation times. The relaxation times of oxygenated and deoxygenated hemoglobin molecules, both possessing extremely low fluorescence quantum yields, were measured at 576 nm. The added advantages in dispersion susceptibility, laser-wavelength availability, reflection sensing, and expense foster the study of natural\u2014including strongly scattering and nonfluorescent\u2014materials.",
"doi": "10.1063/1.3500820",
"pmcid": "PMC2980551",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2010-10-18",
"series_number": "16",
"volume": "97",
"issue": "16",
"pages": "Art. No. 163701"
},
{
"id": "authors:vwsf2-d9x95",
"collection": "authors",
"collection_id": "vwsf2-d9x95",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160920-090918048",
"type": "article",
"title": "Subwavelength-resolution label-free photoacoustic microscopy of optical absorption in vivo",
"author": [
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical absorption provides essential biological functional information but cannot be sensed by mainstream optical microscopy technologies directly, which detect fluorescence or scattering and may require undesirable labeling. Here we developed in vivo subwavelength-resolution photoacoustic microscopy (SW-PAM) that provides exquisitely high optical-absorption contrast due to nonfluorescent, or fluorescent, endogenous pigments. Having approached the ultimate diffraction-limited optical resolution, SW-PAM can resolve subcellular organelles. Vasculature and early-stage melanoma were imaged with 12:1 and 17:1 contrasts, respectively, without labeling. SW-PAM along with the scaled-up macroscopy, as the only technology that measures the same contrast origin over such a wide length scale, can potentially accelerate translation from microscopic research to clinical practice.",
"doi": "10.1364/OL.35.003195",
"pmcid": "PMC2952183",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2010-10-01",
"series_number": "19",
"volume": "35",
"issue": "19",
"pages": "3195-3197"
},
{
"id": "authors:7bffn-h7j12",
"collection": "authors",
"collection_id": "7bffn-h7j12",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160920-084351340",
"type": "article",
"title": "Guest Editorial to the Special Letters Issue on Emerging Technologies in Multiparameter Biomedical Optical Imaging and Image Analysis",
"author": [
{
"family_name": "Gurcan",
"given_name": "Metin N.",
"clpid": "Gurcan-M-N"
},
{
"family_name": "Roysam",
"given_name": "Badrinath",
"clpid": "Roysam-B"
},
{
"family_name": "Dhawan",
"given_name": "Atam P.",
"clpid": "Dhawan-A-P"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The past two decades have witnessed revolutionary advances\nin biomedical imaging modalities capable of providing\nbiological and physiological information from the cellular\nscale to the organ level. Recent advances have also been\nfocused on cost-effective, noninvasive, portable, and molecularimaging\ntechnologies for imaging at microscopic, mesoscopic,\nand macroscopic levels. These technologies have significant\npotential to advance biomedical research and clinical practice.\nThey can also provide a better understanding and monitoring\nof physiological and functional disorders, which could lead to\nmainstream diagnostic technologies of the future.",
"doi": "10.1109/TBME.2010.2072750",
"issn": "0018-9294",
"publisher": "IEEE",
"publication": "IEEE Transactions on Biomedical Engineering",
"publication_date": "2010-10",
"series_number": "10",
"volume": "57",
"issue": "10",
"pages": "2551-2554"
},
{
"id": "authors:1qs0z-pn306",
"collection": "authors",
"collection_id": "1qs0z-pn306",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160830-104712331",
"type": "article",
"title": "Integrated Photoacoustic and Fluorescence Confocal Microscopy",
"author": [
{
"family_name": "Wang",
"given_name": "Yu",
"orcid": "0000-0003-3589-9274",
"clpid": "Wang-Yu"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have developed a dual-modality imaging system by integrating optical-resolution photoacoustic microscopy and fluorescence confocal microscopy to provide optical absorption and fluorescence contrasts simultaneously. By sharing the same laser source and objective lens, intrinsically registered photoacoustic and fluorescence images are acquired in a single scan. The micrometer resolution allows imaging of both blood and lymphatic vessels down to the capillary level. Simultaneous photoacoustic angiography and fluorescence lymphangiography were demonstrated, presenting more information to study tumor angiogenesis, vasculature, and microenvironments in vivo.",
"doi": "10.1109/TBME.2010.2059026",
"pmcid": "PMC2970769",
"issn": "0018-9294",
"publisher": "IEEE",
"publication": "IEEE Transactions on Biomedical Engineering",
"publication_date": "2010-10",
"series_number": "10",
"volume": "57",
"issue": "10",
"pages": "2576-2578"
},
{
"id": "authors:4xazg-y8w64",
"collection": "authors",
"collection_id": "4xazg-y8w64",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200226-092530694",
"type": "article",
"title": "Photoacoustic generation of focused quasi-unipolar pressure pulses",
"author": [
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Zhang",
"given_name": "Hao F.",
"clpid": "Zhang-Hao-F"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The photoacoustic effect was employed to generate short-duration quasi-unipolar acoustic pressure pulses in both planar and spherically focused geometries. In the focal region, the temporal profile of a pressure pulse can be approximated by the first derivative of the temporal profile near the front transducer surface, with a time-averaged value equal to zero. This approximation agreed with experimental results acquired from photoacoustic transducers with both rigid and free boundaries. For a free boundary, the acoustic pressure in the focal region is equal to the sum of a positive pressure that follows the spatial profile of the optical energy deposition in the medium and a negative pressure that follows the temporal profile of the laser pulse.",
"doi": "10.1142/s1793545810001118",
"pmcid": "PMC2997707",
"issn": "1793-5458",
"publisher": "World Scientific Publishing",
"publication": "Journal of Innovative Optical Health Sciences",
"publication_date": "2010-10",
"series_number": "4",
"volume": "3",
"issue": "4",
"pages": "247-253"
},
{
"id": "authors:72dnp-n9y58",
"collection": "authors",
"collection_id": "72dnp-n9y58",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180925-094116035",
"type": "article",
"title": "JBO Is Going Monthly",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A phone book in the mailbox? Recent issues of our Journal of Biomedical Optics have been as thick as an inch (2.5 cm). Having experienced continuous rapid growth, JBO has been publishing >300 papers each year since 2008 (Fig. 1 ). While celebrating the expansion, we recognize that the bimonthly printed issues are unwieldy as well as untimely. Although papers are posted online as soon as they are typeset and approved, we would like to get the printed issues into the hands of our subscribers more frequently and in a more manageable size. Believe it or not, some of us still like to read hard copies or carry them on flights. One of the ten initiatives I made earlier this year was to publish JBO monthly, and this has now been officially approved by SPIE. Starting January 2011, we will see more timely and frequent monthly issues.",
"doi": "10.1117/1.3505724",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2010-09",
"series_number": "5",
"volume": "15",
"issue": "5",
"pages": "Art. No. 050101"
},
{
"id": "authors:c3aqv-m9107",
"collection": "authors",
"collection_id": "c3aqv-m9107",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180918-133821552",
"type": "article",
"title": "Photoacoustic Imaging and Spectroscopy [Book Review]",
"author": [
{
"family_name": "Masters",
"given_name": "Barry R.",
"clpid": "Masters-B-R"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic Imaging and Spectroscopy is a multiauthored reference book that presents an advanced series of disparate chapters on the mathematical foundations, instrumentation, and applications of photoacoustic and thermoacoustic imaging. Lihong Wang, an eminent author, educator, scientist, and leader in the field of photoacoustic imaging and spectroscopy, is the editor of this book. Clearly this field is extremely active as evidenced by the diversity, the scope, and the quality of the field's published literature. Nevertheless, I was surprised to read the back cover, which I think is overreaching with the claim that photoacoustics may make as dynamic a contribution to modern medicine as the discovery of the x ray once did. While this may be a \"typical\" overstatement by the publisher's marketing team, it should be noted that within one year of the discovery of x rays there were more than one thousand publications related to the topic.",
"doi": "10.1117/1.3490399",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2010-09",
"series_number": "5",
"volume": "15",
"issue": "5",
"pages": "Art. No. 059901"
},
{
"id": "authors:encac-tv462",
"collection": "authors",
"collection_id": "encac-tv462",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160830-095334150",
"type": "article",
"title": "In Vivo Molecular Photoacoustic Tomography of Melanomas Targeted by Bioconjugated Gold Nanocages",
"author": [
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Cho",
"given_name": "Eun Chul",
"clpid": "Cho-Eun-Chul"
},
{
"family_name": "Chen",
"given_name": "Jingyi",
"clpid": "Chen-Jingyi"
},
{
"family_name": "Song",
"given_name": "Kwang Hyun",
"clpid": "Song-Kwang-Hyun"
},
{
"family_name": "Au",
"given_name": "Leslie",
"clpid": "Au-Leslie"
},
{
"family_name": "Favazza",
"given_name": "Christopher",
"clpid": "Favazza-C-P"
},
{
"family_name": "Zhang",
"given_name": "Qiang",
"orcid": "0000-0002-8376-131X",
"clpid": "Zhang-Qiang"
},
{
"family_name": "Cobley",
"given_name": "Claire M.",
"clpid": "Cobley-C-M"
},
{
"family_name": "Gao",
"given_name": "Feng",
"clpid": "Gao-Feng"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Early diagnosis, accurate staging, and image-guided resection of melanomas remain crucial clinical objectives for improving patient survival and treatment outcomes. Conventional techniques cannot meet this demand because of the low sensitivity, low specificity, poor spatial resolution, shallow penetration, and/or ionizing radiation. Here we overcome such limitations by combining high-resolution photoacoustic tomography (PAT) with extraordinarily optical absorbing gold nanocages (AuNCs). When bioconjugated with [Nle^4,D-Phe^7]-\u03b1-melanocyte-stimulating hormone, the AuNCs can serve as a novel contrast agent for in vivo molecular PAT of melanomas with both exquisite sensitivity and high specificity. The bioconjugated AuNCs enhanced contrast \u223c300% more than the control, PEGylated AuNCs. The in vivo PAT quantification of the amount of AuNCs accumulated in melanomas was further validated with inductively coupled plasma mass spectrometry (ICP-MS).",
"doi": "10.1021/nn100736c",
"pmcid": "PMC3065066",
"issn": "1936-0851",
"publisher": "American Chemical Society",
"publication": "ACS Nano",
"publication_date": "2010-08-24",
"series_number": "8",
"volume": "4",
"issue": "8",
"pages": "4559-4564"
},
{
"id": "authors:1c72p-6mt77",
"collection": "authors",
"collection_id": "1c72p-6mt77",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190304-153747357",
"type": "article",
"title": "Deeply penetrating in vivo photoacoustic imaging using a clinical ultrasound array system",
"author": [
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Erpelding",
"given_name": "Todd N.",
"clpid": "Erpelding-T-N"
},
{
"family_name": "Jankovic",
"given_name": "Ladislav",
"clpid": "Jankovic-L"
},
{
"family_name": "Pashley",
"given_name": "Michael D.",
"clpid": "Pashley-M-D"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Using a hand-held photoacoustic probe integrated with a clinical ultrasound array system, we successfully imaged objects deeply positioned in biological tissues. The optical contrasts were enhanced by methylene blue with a concentration of ~30 mM. The penetration depth reached ~5.2 cm in chicken breast tissue by using 650-nm wavelength, which is ~4.7 times the 1/e optical penetration depth. This imaging depth was achieved using a laser fluence on the tissue surface of only 3 mJ/cm2, which is 1/7 of the American National Standards Institute (ANSI) safety limit (20 mJ/cm2). The noise equivalent sensitivity at this depth was ~11 mM. Further, after intradermal injection of methylene blue in a rat, a sentinel lymph node was easily detected in vivo, beneath a 2-cm thick layer of chicken breast. Also, blood located 3.5 cm deep in the rat was clearly imaged with intrinsic contrast. We have photoacoustically guided insertion of a needle into a rat sentinel lymph node with accumulated methylene blue. These results highlight the clinical potential of photoacoustic image-guided identification and needle biopsy of sentinel lymph nodes for axillary staging in breast cancer patients.",
"doi": "10.1364/boe.1.000278",
"pmcid": "PMC3005157",
"issn": "2156-7085",
"publisher": "Optical Society of America",
"publication": "Biomedical Optics Express",
"publication_date": "2010-08-02",
"series_number": "1",
"volume": "1",
"issue": "1",
"pages": "278-284"
},
{
"id": "authors:cdaqm-dpf35",
"collection": "authors",
"collection_id": "cdaqm-dpf35",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160908-153729231",
"type": "article",
"title": "Sentinel Lymph Nodes in the Rat: Noninvasive Photoacoustic and US Imaging with a Clinical US System",
"author": [
{
"family_name": "Erpelding",
"given_name": "Todd N.",
"clpid": "Erpelding-T-N"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Pramanik",
"given_name": "Manojit",
"clpid": "Pramanik-M"
},
{
"family_name": "Jankovic",
"given_name": "Ladislav",
"clpid": "Jankovic-L"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Guo",
"given_name": "Zijian",
"clpid": "Guo-Zijian"
},
{
"family_name": "Margenthaler",
"given_name": "Julie A.",
"clpid": "Margenthaler-J-A"
},
{
"family_name": "Pashley",
"given_name": "Michael D.",
"clpid": "Pashley-M-D"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Purpose:\n\nTo evaluate in vivo sentinel lymph node (SLN) mapping by using photoacoustic and ultrasonographic (US) imaging with a modified clinical US imaging system. \n\nMaterials and Methods:\n\nAnimal protocols were approved by the Animal Studies Committee. Methylene blue dye accumulation in axillary lymph nodes of seven healthy Sprague-Dawley rats was imaged by using a photoacoustic imaging system adapted from a clinical US imaging system. To investigate clinical translation, the imaging depth was extended up to 2.5 cm by adding chicken or turkey breast on top of the rat skin surface. Three-dimensional photoacoustic images were acquired by mechanically scanning the US transducer and light delivery fiber bundle along the elevational direction.\n\nResults:\n\nPhotoacoustic images of rat SLNs clearly help visualization of methylene blue accumulation, whereas coregistered photoacoustic/US images depict lymph node positions relative to surrounding anatomy. Twenty minutes following methylene blue injection, photoacoustic signals from SLN regions increased nearly 33-fold from baseline signals in preinjection images, and mean contrast between SLNs and background tissue was 76.0 \u00b1 23.7 (standard deviation). Methylene blue accumulation in SLNs was confirmed photoacoustically by using the optical absorption spectrum of the dye. Three-dimensional photoacoustic images demonstrate dynamic accumulation of methylene blue in SLNs after traveling through lymph vessels.\n\nConclusion:\n\nIn vivo photoacoustic and US mapping of SLNs was successfully demonstrated with a modified clinical US scanner. These results raise confidence that photoacoustic and US imaging can be used clinically for accurate, noninvasive imaging of SLNs for axillary lymph node staging in breast cancer patients.",
"doi": "10.1148/radiol.10091772",
"pmcid": "PMC2897692",
"issn": "0033-8419",
"publisher": "Radiological Society of North America",
"publication": "Radiology",
"publication_date": "2010-07",
"series_number": "1",
"volume": "256",
"issue": "1",
"pages": "102-110"
},
{
"id": "authors:6bd66-qhv76",
"collection": "authors",
"collection_id": "6bd66-qhv76",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160830-091304188",
"type": "article",
"title": "Handheld array-based photoacoustic probe for guiding needle biopsy of sentinel lymph nodes",
"author": [
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Erpelding",
"given_name": "Todd N.",
"clpid": "Erpelding-T-N"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Jankovic",
"given_name": "Ladislav",
"clpid": "Jankovic-L"
},
{
"family_name": "Akers",
"given_name": "Walter J.",
"clpid": "Akers-W-J"
},
{
"family_name": "Song",
"given_name": "Liang",
"clpid": "Song-Liang"
},
{
"family_name": "Achilefu",
"given_name": "Samuel",
"clpid": "Achilefu-S"
},
{
"family_name": "Margenthaler",
"given_name": "Julie A.",
"clpid": "Margenthaler-J-A"
},
{
"family_name": "Pashley",
"given_name": "Michael D.",
"clpid": "Pashley-M-D"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "By modifying a clinical ultrasound array system, we develop a novel handheld photoacoustic probe for image-guided needle biopsy. The integration of optical fiber bundles for pulsed laser light delivery enables photoacoustic image-guided insertion of a needle into rat axillary lymph nodes with accumulated indocyanine green (ICG). Strong photoacoustic contrast of the needle is achieved. After subcutaneous injection of the dye in the left forepaw, sentinel lymph nodes are easily detected, in vivo and in real time, beneath 2-cm \n2-cm-thick chicken breast overlaying the axillary region. ICG uptake in axillary lymph nodes is confirmed with fluorescence imaging both in vivo and ex vivo. These results demonstrate the clinical potential of this handheld photoacoustic system for facile identification and needle biopsy of sentinel lymph nodes for cancer staging and metastasis detection in humans.",
"doi": "10.1117/1.3469829",
"pmcid": "PMC2937045",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2010-07",
"series_number": "4",
"volume": "15",
"issue": "4",
"pages": "Art. No. 046010"
},
{
"id": "authors:x890a-0ht20",
"collection": "authors",
"collection_id": "x890a-0ht20",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160907-145450764",
"type": "article",
"title": "Introduction to the Special Issue on Biophotonics\u2014Part 2",
"author": [
{
"family_name": "Ilev",
"given_name": "Ilko K.",
"clpid": "Ilev-I-K"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Boppart",
"given_name": "Stephen A.",
"clpid": "Boppart-S-A"
},
{
"family_name": "Andersson-Engels",
"given_name": "Stefan",
"clpid": "Andersson-Engels-S"
},
{
"family_name": "Kim",
"given_name": "Beop-Min",
"clpid": "Kim-Beop-Min"
}
],
"abstract": "This Part 2 of the special issue on biophotonics contains 27 papers, including 18 invited and 19 contributed papers.",
"doi": "10.1109/JSTQE.2010.2052483",
"issn": "1077-260X",
"publisher": "IEEE",
"publication": "IEEE Journal of Selected Topics in Quantum Electronics",
"publication_date": "2010-07",
"series_number": "4",
"volume": "16",
"issue": "4",
"pages": "703-705"
},
{
"id": "authors:a61kj-x5d06",
"collection": "authors",
"collection_id": "a61kj-x5d06",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200226-091849493",
"type": "article",
"title": "Neurovascular photoacoustic tomography",
"author": [
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Neurovascular coupling refers to the relationship between neuronal activities and downstream hemodynamic responses. Photoacoustic tomography (PAT), enabling comprehensive label-free imaging of hemodynamic activities with highly scalable penetration and spatial resolution, has great potential in the study of neurovascular coupling. In this review, we first introduce the technical basis of hemodynamic PAT \u2013 including label-free quantification of total hemoglobin concentration, blood oxygenation, and blood flow \u2013 as well as its applications in hemodynamic monitoring. Then, we demonstrate the potential application of PAT in neurovascular imaging by highlighting representative studies on cerebral vascular responses to whisker stimulation and Alzheimer's disease. Finally, potential research directions and associated technical challenges are discussed.",
"doi": "10.3389/fnene.2010.00010",
"pmcid": "PMC2899522",
"issn": "1662-6427",
"publisher": "Frontiers Media SA",
"publication": "Frontiers in Neuroenergetics",
"publication_date": "2010-06-17",
"volume": "2",
"pages": "Art. No. 10"
},
{
"id": "authors:x30jj-eck63",
"collection": "authors",
"collection_id": "x30jj-eck63",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160830-083014111",
"type": "article",
"title": "Calibration-free absolute quantification of optical absorption coefficients using acoustic spectra in 3D photoacoustic microscopy of biological tissue",
"author": [
{
"family_name": "Guo",
"given_name": "Zijian",
"clpid": "Guo-Zijian"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical absorption is closely associated with many physiological important parameters, such as the concentration and oxygen saturation of hemoglobin, and it can be used to quantify the concentrations of nonfluorescent molecules. We propose a method to use acoustic spectra of photoacoustic signals to quantify the absolute optical absorption. This method is self-calibrating and thus insensitive to variations in the optical fluence. Factors such as system bandwidth and acoustic attenuation can affect the quantification but can be canceled by dividing the acoustic spectra measured at two optical wavelengths. Using optical-resolution photoacoustic microscopy, we quantified the absolute optical absorption of black ink samples with various concentrations. We also quantified both the concentration and oxygen saturation of hemoglobin in a live mouse in absolute units.",
"doi": "10.1364/OL.35.002067",
"pmcid": "PMC3071532",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2010-06-15",
"series_number": "12",
"volume": "35",
"issue": "12",
"pages": "2067-2069"
},
{
"id": "authors:rvxz4-3s886",
"collection": "authors",
"collection_id": "rvxz4-3s886",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190306-084226548",
"type": "article",
"title": "High-resolution photoacoustic microscope for rat brain imaging in vivo",
"author": [
{
"family_name": "Yang",
"given_name": "Xiaoquan",
"clpid": "Yang-Xiaoquan"
},
{
"family_name": "Cai",
"given_name": "Xin",
"clpid": "Cai-Xin"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Luo",
"given_name": "Qingming",
"clpid": "Luo-Qingming"
}
],
"abstract": "A reflection-mode photoacoustic microscope (PAM) for rat brain imaging in vivo is constructed. A pulsed laser is used as an excitation source, and a focused ultrasound transducer is adopted to collect the photoacoustic signal. Raster scanning is applied to acquire three-dimensional (3D) data. The obtained measurements of the lateral and axial resolutions of the microscope are 45 and 15 \\mu m, respectively. The imaging depth in the chicken breast tissue is 3.1 mm at a signal-to-noise ratio (SNR) of 20 dB without any signal averaging. The imaging speed is 30 A-line/s. Experimental results in vivo demonstrate the capability of 3D imaging of the brain vessels of the rat after removing the skull.",
"issn": "1671-7694",
"publisher": "Optical Society of America",
"publication": "Chinese Optics Letters",
"publication_date": "2010-06",
"series_number": "6",
"volume": "8",
"issue": "6",
"pages": "609-611"
},
{
"id": "authors:k5f8c-s0q03",
"collection": "authors",
"collection_id": "k5f8c-s0q03",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190305-153255524",
"type": "article",
"title": "Hybrid-scanning optical-resolution photoacoustic microscopy for in vivo vasculature imaging",
"author": [
{
"family_name": "Rao",
"given_name": "Bin",
"orcid": "0000-0001-6494-3110",
"clpid": "Rao-Bin"
},
{
"family_name": "Li",
"given_name": "Li",
"clpid": "Li-Li"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Recently developed optical-resolution photoacoustic microscopy (OR-PAM), which is based on the detection of optical absorption contrast, is complementary to other optical microscopy modalities such as optical confocal microscopy, optical coherence tomography, and multiphoton microscopy. A hybrid optical\u2013mechanical scanning configuration increases the imaging speed of OR-PAM significantly, facilitating many demanding biomedical applications. With a high-pulse-repetition-rate laser, the hybrid-scanning OR-PAM can acquire one-dimensional depth-resolved images (A-lines) at 5\u2009kHz and two-dimensional B-scan images containing 800 A-lines at 6.25\u2009Hz. We demonstrated in vivo in a mouse three-dimensional imaging of the iris vasculature in 128\u2009s for an 800\u00d7800\u00d7200 data set and of the ear vasculature in 256\u2009s for an 800\u00d71600\u00d7200 data set.",
"doi": "10.1364/ol.35.001521",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2010-05-15",
"series_number": "10",
"volume": "35",
"issue": "10",
"pages": "1521-1523"
},
{
"id": "authors:916nm-rkw88",
"collection": "authors",
"collection_id": "916nm-rkw88",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160908-105859565",
"type": "article",
"title": "Section-illumination photoacoustic microscopy for dynamic 3D imaging of microcirculation in vivo",
"author": [
{
"family_name": "Song",
"given_name": "Liang",
"clpid": "Song-Liang"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We developed section-illumination photoacoustic microscopy capable of dynamic in vivo imaging of microvessels as small as 30\u2009\u03bcm in diameter. The section illumination improved the elevational resolution while an ultrasound array provided the in-plane axial and lateral resolutions. Using the imaging system, we monitored the wash-in dynamics of Evans Blue in the microcirculation of mouse ears at 249\u2009Hz 2D and 0.5\u2009Hz 3D image acquisition rates. Such observation allowed us to differentiate the arterioles from the venules. In the future, the technology may be used to study angiogenesis, diabetes-induced vascular complications, and pharmacokinetics.",
"doi": "10.1364/OL.35.001482",
"pmcid": "PMC2941522",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2010-05-01",
"series_number": "9",
"volume": "35",
"issue": "9",
"pages": "1482-1484"
},
{
"id": "authors:6kz4e-ajc72",
"collection": "authors",
"collection_id": "6kz4e-ajc72",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160830-102505514",
"type": "article",
"title": "In vivo photoacoustic imaging of transverse blood flow by using Doppler broadening of bandwidth",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Maslov",
"given_name": "Konstantin I.",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Shi",
"given_name": "Yunfei",
"clpid": "Shi-Yunfei"
},
{
"family_name": "Taber",
"given_name": "Larry A.",
"clpid": "Taber-L-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A method is proposed to measure transverse blood flow by using photoacoustic Doppler broadening of bandwidth. By measuring bovine blood flowing through a plastic tube, the linear dependence of the broadening on the flow speed was validated. The blood flow of the microvasculature in a mouse ear and a chicken embryo (stage 16) was also studied.",
"doi": "10.1364/OL.35.001419",
"pmcid": "PMC2916025",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2010-05-01",
"series_number": "9",
"volume": "35",
"issue": "9",
"pages": "1419-1421"
},
{
"id": "authors:r1y9t-qvn03",
"collection": "authors",
"collection_id": "r1y9t-qvn03",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160706-142126990",
"type": "article",
"title": "Photoacoustic tomography of water in phantoms and tissue",
"author": [
{
"family_name": "Xu",
"given_name": "Zhun",
"clpid": "Xu-Zhun"
},
{
"family_name": "Li",
"given_name": "Changhui",
"clpid": "Li-Changhui"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) has been widely used to image optically absorptive objects in both human and animal tissues. For the first time, we present imaging of water with laser-based PAT. We photoacoustically measure the absorption spectra of water-ethanol mixtures at various water concentrations, and then image water-ethanol and pure-water inclusions in gel and a water inclusion in fat tissue. The significant difference in photoacoustic signals between water and fat tissue indicates that the laser-based PAT has the potential to detect water content in tissue.",
"doi": "10.1117/1.3443793",
"pmcid": "PMC2904025",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2010-05",
"series_number": "3",
"volume": "15",
"issue": "3",
"pages": "Art. No. 036019"
},
{
"id": "authors:6g88x-58a29",
"collection": "authors",
"collection_id": "6g88x-58a29",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160830-103451115",
"type": "article",
"title": "In Vivo Photoacoustic Tomography of Chemicals: High-Resolution Functional and Molecular Optical Imaging at New Depths",
"author": [
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Favazza",
"given_name": "Christopher",
"clpid": "Favazza-C-P"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "High-resolution volumetric optical imaging modalities,\nsuch as confocal microscopy, two-photon microscopy, and\noptical coherence tomography, have become increasingly\nimportant in the biomedical imaging field. However, due to\nstrong light scattering, the penetration depths of these\nimaging modalities are limited to the optical transport mean\nfree path in biological tissues, for example, \u223c1 mm in the\nskin. Photoacoustic tomography (PAT), an emerging hybrid\nimaging modality that can provide strong endogenous and\nexogenous optical absorption contrasts with high ultrasonic\nspatial resolution using the photoacoustic (PA) effect, has\novercome the fundamental depth limitation. The image\nresolution is scalable with the ultrasonic frequency. The\nimaging depth is limited to the reach of photons and up to\na few centimeters deep in biological tissues. This Review\nwill focus on the following aspects of PAT described in\nworks published from 2003 to 2009: (1) multiscale PAT\nsystems, (2) morphological and functional PAT using\nintrinsic contrasts (hemoglobin or melanin), and (3) functional\nand molecular PAT using exogenous contrast agents\n(organic dyes, nanoparticles, reporter genes, or fluorescence\nproteins).",
"doi": "10.1021/cr900266s",
"pmcid": "PMC2872199",
"issn": "0009-2665",
"publisher": "American Chemical Society",
"publication": "Chemical Reviews",
"publication_date": "2010-05",
"series_number": "5",
"volume": "110",
"issue": "5",
"pages": "2756-2782"
},
{
"id": "authors:8vszr-6s831",
"collection": "authors",
"collection_id": "8vszr-6s831",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160908-152935477",
"type": "article",
"title": "Sentinel Lymph Nodes and Lymphatic Vessels: Noninvasive Dual-Modality in Vivo Mapping by Using Indocyanine Green in Rats\u2014Volumetric Spectroscopic Photoacoustic Imaging and Planar Fluorescence Imaging",
"author": [
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Song",
"given_name": "Kwang Hyun",
"clpid": "Song-Kwang-Hyun"
},
{
"family_name": "Gao",
"given_name": "Feng",
"clpid": "Gao-Feng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Purpose: \n\nTo noninvasively map sentinel lymph nodes (SLNs) and lymphatic vessels in rats in vivo by using dual-modality nonionizing imaging\u2014volumetric spectroscopic photoacoustic imaging, which measures optical absorption, and planar fluorescence imaging, which measures fluorescent emission\u2014of indocyanine green (ICG).\n\nMaterials and Methods: \n\nInstitutional animal care and use committee approval was obtained. Healthy Sprague-Dawley rats weighing 250\u2212420 g (age range, 60\u2212120 days) were imaged by using volumetric photoacoustic imaging (n = 5) and planar fluorescence imaging (n = 3) before and after injection of 1 mmol/L ICG. Student paired t tests based on a logarithmic scale were performed to evaluate the change in photoacoustic signal enhancement of SLNs and lymphatic vessels before and after ICG injection. The spatial resolutions of both imaging systems were compared at various imaging depths (2\u20138 mm) by layering additional biologic tissues on top of the rats in vivo. Spectroscopic photoacoustic imaging was applied to identify ICG-dyed SLNs. \n\nResults: \n\nIn all five rats examined with photoacoustic imaging, SLNs were clearly visible, with a mean signal enhancement of 5.9 arbitrary units (AU) \u00b1 1.8 (standard error of the mean) (P < .002) at 0.2 hour after injection, while lymphatic vessels were seen in four of the five rats, with a signal enhancement of 4.3 AU \u00b1 0.6 (P = .001). In all three rats examined with fluorescence imaging, SLNs and lymphatic vessels were seen. The average full width at half maximum (FWHM) of the SLNs in the photoacoustic images at three imaging depths (2, 6, and 8 mm) was 2.0 mm \u00b1 0.2 (standard deviation), comparable to the size of a dissected lymph node as measured with a caliper. However, the FWHM of the SLNs in fluorescence images widened from 8 to 22 mm as the imaging depth increased, owing to strong light scattering. SLNs were identified spectroscopically in photoacoustic images. \n\nConclusion: \n\nThese two modalities, when used together with ICG, have the potential to help map SLNs in axillary staging and to help evaluate tumor metastasis in patients with breast cancer.",
"doi": "10.1148/radiol.10090281",
"pmcid": "PMC2858815",
"issn": "0033-8419",
"publisher": "Radiological Society of North America",
"publication": "Radiology",
"publication_date": "2010-05",
"series_number": "2",
"volume": "255",
"issue": "2",
"pages": "442-450"
},
{
"id": "authors:0ev8p-jfg73",
"collection": "authors",
"collection_id": "0ev8p-jfg73",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160907-145939004",
"type": "article",
"title": "Introduction to the Special Issue on Biophotonics\u2014Part 1",
"author": [
{
"family_name": "Ilev",
"given_name": "Ilko K.",
"clpid": "Ilev-I-K"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Boppart",
"given_name": "Stephen A.",
"clpid": "Boppart-S-A"
},
{
"family_name": "Andersson-Engels",
"given_name": "Stefan",
"clpid": "Andersson-Engels-S"
},
{
"family_name": "Kim",
"given_name": "Beop-Min",
"clpid": "Kim-Beop-Min"
}
],
"abstract": "The first part of this special issue on biophotonics can be broken down into six sections: 1) advanced bioimaging and microscopy; 2) novel approaches in biophotonic diagnostics and therapeutics; 3) photoacoustic tomography; 4) light-cell and light-tissue interactions; 5) novel biosensing techniques; and 6) advanced nanobiophotonics. There are 23 papers in this issue.",
"doi": "10.1109/JSTQE.2010.2048255",
"issn": "1077-260X",
"publisher": "IEEE",
"publication": "IEEE Journal of Selected Topics in Quantum Electronics",
"publication_date": "2010-05",
"series_number": "3",
"volume": "16",
"issue": "3",
"pages": "475-477"
},
{
"id": "authors:fegmc-as712",
"collection": "authors",
"collection_id": "fegmc-as712",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180925-091636961",
"type": "article",
"title": "Review Speed",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "I am pleased to report on the progress that JBO has made toward shortening the manuscript-review cycle. As of the end of April 2010, the average time from receipt to first decision has been improved to 40 days for full-length manuscripts and 25 days for letter-length manuscripts. These review speeds are considered highly competitive among journals on optics\u2014moreover, all JBO Letters are openly accessible online free of charge. This feat would not have been possible without hard work by the journal staff, editorial board members, and numerous reviewers.\n\nWhile maintaining sufficient time windows for the reviewers, we would like to condense the other phases of the review cycles further. Authors, as the experts most versed in their fields, are strongly encouraged to suggest 2\u20133 editorial board members and 4\u20136 potential reviewers during online manuscript submission. Such information is invaluable: reviewers whose interests are germane to the submitted work have greater inclinations to accept the review invitations and complete the reviews on time. These suggestions will be used at the discretion of the editor and editorial board members. \n\nLet me express my gratitude for all your contributions to JBO. Any further suggestions are most welcome.",
"doi": "10.1117/1.3446798",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2010-05",
"series_number": "3",
"volume": "15",
"issue": "3",
"pages": "Art. No. 030101"
},
{
"id": "authors:hpva2-68p63",
"collection": "authors",
"collection_id": "hpva2-68p63",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160706-134530692",
"type": "article",
"title": "Near infrared photoacoustic detection of sentinel lymph nodes with gold nanobeacons",
"author": [
{
"family_name": "Pan",
"given_name": "Dipanjan",
"clpid": "Pan-Dipanjan"
},
{
"family_name": "Pramanik",
"given_name": "Manojit",
"clpid": "Pramanik-M"
},
{
"family_name": "Senpan",
"given_name": "Angana",
"clpid": "Senpan-A"
},
{
"family_name": "Ghosh",
"given_name": "Soumojit",
"clpid": "Ghosh-Soumojit"
},
{
"family_name": "Wickline",
"given_name": "Samuel A.",
"clpid": "Wickline-S-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Lanza",
"given_name": "Gregory M.",
"clpid": "Lanza-G-M"
}
],
"abstract": "Detection of sentinel lymph node (SLN) using photoacoustic imaging is an emerging technique for noninvasive axillary staging of breast cancer. Due to the absence of intrinsic contrast inside the lymph nodes, exogenous contrast agents are used for photoacoustic detection. In this work, we have demonstrated near infrared detection of SLN with gold nanobeacons (GNBs) providing the photoacoustic contrast in a rodent model. We found that size dictates the in vivo characteristics of these nanoparticles in SLN imaging. Larger nanobeacons with high payloads of gold were not as efficient as smaller size nanobeacons with lower payloads for this purpose. Colloidal GNBs were designed as a nanomedicine platform with \"soft\" nature that is amenable to bio-elimination, an essential feature for in vivo efficacy and safety. The GNBs were synthesized as lipid- or polymer-encapsulated colloidal particles incorporating tiny gold nanoparticles (2\u20134 nm) in three tunable sizes (90 nm, 150 nm and 290 nm). Smaller GNBs were noted trafficking through the lymphatic system and accumulating more efficiently in the lymph nodes in comparison to the bigger nanoagents. At 20 min, the GNBs reached the SLN and were no longer observed within the draining lymphatic vessel. Within 1 h post-injection, the contrast ratio of the lymph nodes with the surrounding blood vessels was 9:1. These findings were also supported by analytical measurements of the ex vivo tissue samples. Results indicate that cumulative nanoparticle deposition in lymph nodes is size dependent and that high payloads of gold, although offering greater contrast in vitro, may yield nanoagents with poor intradermal migration and lymphatic transport characteristics.",
"doi": "10.1016/j.biomaterials.2010.01.136",
"pmcid": "PMC2874457",
"issn": "0142-9612",
"publisher": "Elsevier",
"publication": "Biomaterials",
"publication_date": "2010-05",
"series_number": "14",
"volume": "31",
"issue": "14",
"pages": "4088-4093"
},
{
"id": "authors:vwcj0-seh86",
"collection": "authors",
"collection_id": "vwcj0-seh86",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160701-133411171",
"type": "article",
"title": "In vivo photoacoustic microscopy of human skin",
"author": [
{
"family_name": "Favazza",
"given_name": "C.",
"clpid": "Favazza-C"
},
{
"family_name": "Jassim",
"given_name": "O.",
"clpid": "Jassim-O"
},
{
"family_name": "Wang",
"given_name": "L. V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Cornelius",
"given_name": "L.",
"clpid": "Cornelius-L-A"
}
],
"abstract": "Microcirculation is an important component of the cardiovascular system and can be used to assess systemic cardiovascular health. Numerous studies have investigated cutaneous microcirculation as an indicator of cardiovascular related diseases. Such research has shown promising results; however, there are many limitations regarding the employed measurement techniques, such as poor depth and spatial resolution and measurement versatility. Here we show the results of functional cutaneous microvascular experiments measured with photoacoustic microscopy, which provides high spatial resolution and multiparameter measurements. In a set of experiments, microvascular networks located in the palms of volunteers were perturbed by periodic ischemic events, and the subsequent hemodynamic response to the stimulus was recorded. Results indicate that during periods of arterial occlusion, the relative oxygen saturation of the capillary vessels decreased below resting levels, and temporarily increased above resting levels immediately following the occlusion. Furthermore, a hyperemic reaction to the occlusions was measured, and the observation agreed well with similar measurements using more conventional imaging techniques. Due to its exceptional capability to functionally image vascular networks with high spatial resolution, photoacoustic microscopy could be a beneficial biomedical tool to assess microvascular functioning and applied to patients with diseases that affect cardiovascular health.",
"doi": "10.1038/jid.2010.71",
"issn": "0022-202X",
"publisher": "Nature Publishing Group",
"publication": "Journal of Investigative Dermatology",
"publication_date": "2010-04",
"series_number": "S1",
"volume": "130",
"issue": "S1",
"pages": "S145"
},
{
"id": "authors:ata97-0cs07",
"collection": "authors",
"collection_id": "ata97-0cs07",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160708-090935796",
"type": "article",
"title": "Transverse flow imaging based on photoacoustic Doppler bandwidth broadening",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We propose a new method to measure transverse flow velocity based on photoacoustic Doppler bandwidth broadening, which is determined by the geometry of the probe-beam and the velocity of the transverse flow. By exploiting pulsed laser excitation and raster motor scanning, three-dimensional structure and flow velocity can be imaged simultaneously. In addition, the flow direction can be determined with bidirectional scanning. In a flowing suspension of red-dyed microspheres (diameter: 6\u03bcm), transverse flow speeds ranging from 0 to 2.5mm/s as well as flow direction were measured. A cross-sectional flow image was also obtained with the tube laid in a zigzag pattern.",
"doi": "10.1117/1.3339953",
"pmcid": "PMC2857455",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2010-03-23",
"series_number": "2",
"volume": "15",
"issue": "2",
"pages": "Art. No. 021304"
},
{
"id": "authors:bm6kq-sny51",
"collection": "authors",
"collection_id": "bm6kq-sny51",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160614-092951940",
"type": "article",
"title": "Photons Plus Ultrasound: Imaging and Sensing",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Oraevsky",
"given_name": "Alexander A.",
"orcid": "0000-0002-9212-6211",
"clpid": "Oraevsky-A-A"
}
],
"abstract": "Imaging and sensing based on fusing the compelling features of optical and ultrasonic waves is the fastest growing area of research in biomedical optics. The annual SPIE conference on this topic, co-chaired by both of us, has been doubling in size approximately every three years since 2003 (Fig. 1). As of 2009, this conference has become the largest at SPIE Photonics West. Hybrid modalities such as photoacoustic or optoacoustic tomography can provide deep tissue penetration, high ultrasonic resolution, and speckle-free optical contrast. Applications include in vivo functional and molecular imaging of cancer, neurophysiology, and vascular disease in both animals and humans. Major challenges include development of quantitative imaging, improvement of contrast and resolution, and commercialization of the technology. We look forward to seeing significant preclinical and clinical impact from this emerging technology.",
"doi": "10.1117/1.3427141",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2010-03",
"series_number": "2",
"volume": "15",
"issue": "2",
"pages": "Art. No. 021301"
},
{
"id": "authors:tgsyr-1st63",
"collection": "authors",
"collection_id": "tgsyr-1st63",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160706-132545201",
"type": "article",
"title": "Photoacoustic imaging of living mouse brain vasculature using hollow gold nanospheres",
"author": [
{
"family_name": "Lu",
"given_name": "Wei",
"clpid": "Lu-Wei"
},
{
"family_name": "Huang",
"given_name": "Qian",
"clpid": "Huang-Qian"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wen",
"given_name": "Xiaoxia",
"clpid": "Wen-Xiaoxia"
},
{
"family_name": "Zhou",
"given_name": "Min",
"clpid": "Zhou-Min"
},
{
"family_name": "Guzatov",
"given_name": "Dmitry",
"clpid": "Guzatov-D"
},
{
"family_name": "Brecht",
"given_name": "Peter",
"clpid": "Brecht-P"
},
{
"family_name": "Su",
"given_name": "Richard",
"clpid": "Su-Richard"
},
{
"family_name": "Oraevsky",
"given_name": "Alexander",
"orcid": "0000-0002-9212-6211",
"clpid": "Oraevsky-A-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Li",
"given_name": "Chun",
"clpid": "Li-Chun"
}
],
"abstract": "Photoacoustic tomography (PAT) also referred to as optoacoustic tomography (OAT) is a hybrid imaging modality that employs nonionizing optical radiation and ultrasonic detection. Here, we describe the application of a new class of optical contrast agents based on mesoscopic hollow gold nanospheres (HAuNS) to PAT. HAuNS are \u223c40 nm in diameter with a hollow interior and consist of a thin gold wall. They display strong resonance absorption tuned to the near-infrared (NIR) range, with an absorption peak at 800 nm, whose photoacoustic efficiency is significantly greater than that of blood. Following surface conjugation with thiolated poly(ethylene glycol), the pegylated HAuNS (PEG-HAuNS) had distribution and elimination half-lives of 1.38 \u00b1 0.38 and 71.82 \u00b1 30.46 h, respectively. Compared with PAT images based on the intrinsic optical contrast in nude mice, the PAT images acquired within 2 h after intravenous administration of PEG-HAuNS showed the brain vasculature with greater clarity and detail. The image depicted brain blood vessels as small as \u223c100 \u03bcm in diameter using PEG-HAuNS as contrast agents. Preliminary results showed no acute toxicity to the liver, spleen, or kidneys in mice following a single imaging dose of PEG-HAuNS. Our results indicate that PEG-HAuNS are promising contrast agents for PAT, with high spatial resolution and enhanced sensitivity.",
"doi": "10.1016/j.biomaterials.2009.12.007",
"pmcid": "PMC2813997",
"issn": "0142-9612",
"publisher": "Elsevier",
"publication": "Biomaterials",
"publication_date": "2010-03",
"series_number": "9",
"volume": "31",
"issue": "9",
"pages": "2617-2626"
},
{
"id": "authors:99jpe-a1m39",
"collection": "authors",
"collection_id": "99jpe-a1m39",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160711-130135605",
"type": "article",
"title": "Compressed sensing in photoacoustic tomography in vivo",
"author": [
{
"family_name": "Guo",
"given_name": "Zijian",
"clpid": "Guo-Zijian"
},
{
"family_name": "Li",
"given_name": "Changhui",
"clpid": "Li-Changhui"
},
{
"family_name": "Song",
"given_name": "Liang",
"clpid": "Song-Liang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The data acquisition speed in photoacoustic computed tomography (PACT) is limited by the laser repetition rate and the number of parallel ultrasound detecting channels. Reconstructing an image with fewer measurements can effectively accelerate the data acquisition and reduce the system cost. We adapt compressed sensing (CS) for the reconstruction in PACT. CS-based PACT is implemented as a nonlinear conjugate gradient descent algorithm and tested with both phantom and in vivo experiments.",
"doi": "10.1117/1.3381187",
"pmcid": "PMC2866258",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2010-03",
"series_number": "2",
"volume": "15",
"issue": "2",
"pages": "Art. No. 021311"
},
{
"id": "authors:k8ac1-fyn84",
"collection": "authors",
"collection_id": "k8ac1-fyn84",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160712-100605392",
"type": "article",
"title": "Ultrasound-array-based real-time photoacoustic microscopy of human pulsatile dynamics in vivo",
"author": [
{
"family_name": "Song",
"given_name": "Liang",
"clpid": "Song-Liang"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "With a refined ultrasound-array-based real-time photoacoustic microscopy (UA-PAM) system, we demonstrate the feasibility of noninvasive in vivo imaging of human pulsatile dynamics. The system, capable of real-time B-scan imaging at 50Hz and high-speed 3-D imaging, is validated by imaging the subcutaneous microvasculature in rats and humans. After the validation, a human artery around the palm-wrist area is imaged, and its pulsatile dynamics, including the arterial pulsatile motion and changes in hemoglobin concentration, is monitored with 20-ms B-scan imaging temporal resolution. To our knowledge, this is the first demonstration of real-time photoacoustic imaging of human physiological dynamics. Our results show that UA-PAM can potentially enable many new possibilities for studying functional and physiological dynamics in both preclinical and clinical imaging settings.",
"doi": "10.1117/1.3333545",
"pmcid": "PMC2850586",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2010-03",
"series_number": "2",
"volume": "15",
"issue": "2",
"pages": "Art. No. 021303"
},
{
"id": "authors:7ce87-cq933",
"collection": "authors",
"collection_id": "7ce87-cq933",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160830-085658187",
"type": "article",
"title": "Fast and Robust Deconvolution-Based Image Reconstruction for Photoacoustic Tomography in Circular Geometry: Experimental Validation",
"author": [
{
"family_name": "Zhang",
"given_name": "Chi",
"orcid": "0000-0002-1324-2311",
"clpid": "Zhang-Chi"
},
{
"family_name": "Li",
"given_name": "Changhui",
"clpid": "Li-Changhui"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) is a fast-developing biomedical imaging technology suitable for in vivo imaging. PAT in spherical or circular geometry gives good image resolution yet is slow or expensive in signal acquisition and image formation. Reducing the number of detection angles can ameliorate such issues, usually at the expense of image quality. This paper introduces a deconvolution-based algorithm that models the imaging process as a linear and shift-invariant system. As demonstrated by the in vivo experiment, this algorithm not only runs much faster than the back-projection algorithm but also shows stronger robustness in that it provides better image quality when detection angles are sparse. Therefore, this algorithm promises to enable real-time PAT in circular geometry.",
"doi": "10.1109/JPHOT.2010.2042801",
"pmcid": "PMC2954598",
"issn": "1943-0655",
"publisher": "IEEE",
"publication": "IEEE Photonics Journal",
"publication_date": "2010-02",
"series_number": "1",
"volume": "2",
"issue": "1",
"pages": "57-66"
},
{
"id": "authors:azkvj-87b32",
"collection": "authors",
"collection_id": "azkvj-87b32",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160908-103450834",
"type": "article",
"title": "Photoacoustic microscopy with 2-\u03bcm transverse resolution",
"author": [
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Li",
"given_name": "Li",
"clpid": "Li-Li"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present a new-generation optical-resolution confocal photoacoustic microscope, consisting of a 0.25\u2013numerical aperture optical microscope objective and a 75-MHz center-frequency spherically focused ultrasonic transducer. Experiments verified that this microscope has a transverse resolution of 2\u03bcm, which is the highest to our knowledge among all photoacoustic imaging systems. In situ imaging of mouse ears shows the feasibility of resolving individual red blood cells in microvessels using the current system.",
"doi": "10.1117/1.3339912",
"pmcid": "PMC2857454",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2010-02",
"series_number": "2",
"volume": "15",
"issue": "2",
"pages": "Art. No. 021302"
},
{
"id": "authors:wh723-ea256",
"collection": "authors",
"collection_id": "wh723-ea256",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160908-104857895",
"type": "article",
"title": "Saturation effect in functional photoacoustic imaging",
"author": [
{
"family_name": "Wang",
"given_name": "Jing",
"orcid": "0000-0003-2078-137X",
"clpid": "Wang-Jing"
},
{
"family_name": "Liu",
"given_name": "Tan",
"clpid": "Liu-Tan"
},
{
"family_name": "Jiao",
"given_name": "Shuliang",
"clpid": "Jiao-Shuliang"
},
{
"family_name": "Chen",
"given_name": "Ruimin",
"orcid": "0000-0002-5338-359X",
"clpid": "Chen-Ruimin"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Zhang",
"given_name": "Hao F.",
"clpid": "Zhang-Hao-F"
}
],
"abstract": "We investigate the saturation effect, which describes the violation of the linearity between the measured photoacoustic amplitude and the object's optical absorption coefficient in functional photoacoustic imaging when the optical absorption in the object increases. We model the optical energy deposition and photoacoustic signal generation and detection in a semi-infinite optical absorbing object. Experiments are carried out by measuring photoacoustic signals generated from an ink-filled plastic tube. The saturation effect is studied by varying the optical absorption coefficient in the model and the ink concentration in the photoacoustic experiments. By changing the center frequency of the ultrasonic detector, the requirement to minimize the saturation effect in functional photoacoustic imaging is established.",
"doi": "10.1117/1.3333549",
"pmcid": "PMC3188629",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2010-02",
"series_number": "2",
"volume": "15",
"issue": "2",
"pages": "Art. No. 021317"
},
{
"id": "authors:tncxp-8e952",
"collection": "authors",
"collection_id": "tncxp-8e952",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160907-152405107",
"type": "article",
"title": "Label-free photoacoustic ophthalmic angiography",
"author": [
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Rao",
"given_name": "Bin",
"orcid": "0000-0001-6494-3110",
"clpid": "Rao-Bin"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present label-free functional photoacoustic imaging of the ocular microvasculature in living animals. The anterior segment of an adult mouse was imaged with a laser exposure level well within the American National Standards Institute safety standards. Individual red blood cells traveling along the iris capillaries were clearly resolved, and the hemoglobin oxygen saturation in the iris microvasculature was imaged spectrally. We believe that photoacoustic imaging has the potential to advance the diagnosis and treatment of ocular diseases in humans.",
"doi": "10.1364/OL.35.000001",
"pmcid": "PMC2912610",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2010-01-01",
"series_number": "1",
"volume": "35",
"issue": "1",
"pages": "1-3"
},
{
"id": "authors:pfkgp-7c298",
"collection": "authors",
"collection_id": "pfkgp-7c298",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160907-155320765",
"type": "article",
"title": "Multifunctional microbubbles and nanobubbles for photoacoustic and ultrasound imaging",
"author": [
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Qin",
"given_name": "Ruogu",
"clpid": "Qin-Ruogu"
},
{
"family_name": "Xu",
"given_name": "Jeff S.",
"clpid": "Xu-Jeff-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xu",
"given_name": "Ronald",
"clpid": "Xu-Ronald"
}
],
"abstract": "We develop a novel dual-modal contrast agent\u2014encapsulated-ink poly(lactic-co-glycolic acid) (PLGA) microbubbles and nanobubbles\u2014for photoacoustic and ultrasound imaging. Soft gelatin phantoms with embedded tumor simulators of encapsulated-ink PLGA microbubbles and nanobubbles in various concentrations are clearly shown in both photoacoustic and ultrasound images. In addition, using photoacoustic imaging, we successfully image the samples positioned below 1.8-cm-thick chicken breast tissues. Potentially, simultaneous photoacoustic and ultrasound imaging enhanced by encapsulated-dye PLGA microbubbles or nanobubbles can be a valuable tool for intraoperative assessment of tumor boundaries and therapeutic margins.",
"doi": "10.1117/1.3302808",
"pmcid": "PMC2839794",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2010-01",
"series_number": "1",
"volume": "15",
"issue": "1",
"pages": "Art. No. 010510"
},
{
"id": "authors:zy420-vtm36",
"collection": "authors",
"collection_id": "zy420-vtm36",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160908-104214051",
"type": "article",
"title": "Real-time photoacoustic tomography of cortical hemodynamics in small animals",
"author": [
{
"family_name": "Li",
"given_name": "Changhui",
"clpid": "Li-Changhui"
},
{
"family_name": "Aguirre",
"given_name": "Andres",
"clpid": "Aguirre-A"
},
{
"family_name": "Gamelin",
"given_name": "John",
"clpid": "Gamelin-J"
},
{
"family_name": "Maurudis",
"given_name": "Anastasios",
"clpid": "Maurudis-A"
},
{
"family_name": "Zhu",
"given_name": "Quing",
"clpid": "Zhu-Quing"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "For the first time, the hemodynamics within the entire cerebral cortex of a mouse were studied by using photoacoustic tomography (PAT) in real time. The PAT system, based on a 512-element full-ring ultrasound array, received photoacoustic signals primarily from a slice of 2-mm thickness. This system can provide high-resolution brain vasculature images. We also monitored the fast wash-in process of a photoacoustic contrast agent in the mouse brain. Our results demonstrated that PAT is a powerful imaging modality that can be potentially used to study small animal neurofunctional activities.",
"doi": "10.1117/1.3302807",
"pmcid": "PMC2839793",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2010-01",
"series_number": "1",
"volume": "15",
"issue": "1",
"pages": "Art. No. 010509"
},
{
"id": "authors:h96sk-2ka45",
"collection": "authors",
"collection_id": "h96sk-2ka45",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160908-103012705",
"type": "article",
"title": "Photoacoustic imaging and characterization of the microvasculature",
"author": [
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic (optoacoustic) tomography, combining optical absorption contrast and highly scalable spatial resolution (from micrometer optical resolution to millimeter acoustic resolution), has broken through the fundamental penetration limit of optical ballistic imaging modalities\u2014including confocal microscopy, two-photon microscopy, and optical coherence tomography\u2014and has achieved high spatial resolution at depths down to the diffusive regime. Optical absorption contrast is highly desirable for microvascular imaging and characterization because of the presence of endogenous strongly light-absorbing hemoglobin. We focus on the current state of microvascular imaging and characterization based on photoacoustics. We first review the three major embodiments of photoacoustic tomography: microscopy, computed tomography, and endoscopy. We then discuss the methods used to characterize important functional parameters, such as total hemoglobin concentration, hemoglobin oxygen saturation, and blood flow. Next, we highlight a few representative applications in microvascular-related physiological and pathophysiological research, including hemodynamic monitoring, chronic imaging, tumor-vascular interaction, and neurovascular coupling. Finally, several potential technical advances toward clinical applications are suggested, and a few technical challenges in contrast enhancement and fluence compensation are summarized.",
"doi": "10.1117/1.3281673",
"pmcid": "PMC2821418",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2010-01",
"series_number": "1",
"volume": "15",
"issue": "1",
"pages": "Art. No. 011101"
},
{
"id": "authors:xyey0-8bv46",
"collection": "authors",
"collection_id": "xyey0-8bv46",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-082251059",
"type": "article",
"title": "Intravital imaging of amyloid plaques in a transgenic mouse model using optical-resolution photoacoustic microscopy",
"author": [
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Yang",
"given_name": "Ping",
"clpid": "Yang-Ping"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Lee",
"given_name": "Jin-Moo",
"clpid": "Lee-Jin-Moo"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We report optical-resolution photoacoustic microscopy (OR-PAM) for in vivo imaging of amyloid plaques in an Alzheimer's disease mouse model. Validation using conventional fluorescence microscopy and multiphoton microscopy shows that OR-PAM has sufficient sensitivity and spatial resolution to identify amyloid plaques in living brains. In addition, with dual-wavelength OR-PAM, the three-dimensional morphology of amyloid plaques and the surrounding microvasculature are imaged simultaneously through a cranial window without angiographic contrast agents. OR-PAM, capable of providing both exogenous molecular contrast and endogenous hemoglobin contrast, has the potential to serve as a new technology for in vivo microscopic observations of cerebral plaque deposits.",
"doi": "10.1364/OL.34.003899",
"pmcid": "PMC2854007",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2009-12-15",
"series_number": "24",
"volume": "34",
"issue": "24",
"pages": "3899-3901"
},
{
"id": "authors:kjmhb-6cd98",
"collection": "authors",
"collection_id": "kjmhb-6cd98",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160615-091530986",
"type": "article",
"title": "Gold nanocages covered by smart polymers for controlled release with near-infrared light",
"author": [
{
"family_name": "Yavuz",
"given_name": "Mustafa S.",
"clpid": "Yavuz-M-S"
},
{
"family_name": "Cheng",
"given_name": "Yiyun",
"clpid": "Cheng-Yiyun"
},
{
"family_name": "Chen",
"given_name": "Jingyi",
"clpid": "Chen-Jingyi"
},
{
"family_name": "Cobley",
"given_name": "Claire M.",
"clpid": "Cobley-C-M"
},
{
"family_name": "Zhang",
"given_name": "Qiang",
"orcid": "0000-0002-8376-131X",
"clpid": "Zhang-Qiang"
},
{
"family_name": "Rycenga",
"given_name": "Matthew",
"clpid": "Rycenga-M"
},
{
"family_name": "Xie",
"given_name": "Jingwei",
"clpid": "Xie-Jingwei"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Song",
"given_name": "Kwang H.",
"clpid": "Song-Kwang-H"
},
{
"family_name": "Schwartz",
"given_name": "Andrea G.",
"clpid": "Schwartz-A-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "Photosensitive caged compounds have enhanced our ability to address the complexity of biological systems by generating effectors with remarkable spatial/temporal resolutions. The caging effect is typically removed by photolysis with ultraviolet light to liberate the bioactive species. Although this technique has been successfully applied to many biological problems, it suffers from a number of intrinsic drawbacks. For example, it requires dedicated efforts to design and synthesize a precursor compound for each effector. The ultraviolet light may cause damage to biological samples and is suitable only for in vitro studies because of its quick attenuation in tissue. Here we address these issues by developing a platform based on the photothermal effect of gold nanocages. Gold nanocages represent a class of nanostructures with hollow interiors and porous walls. They can have strong absorption (for the photothermal effect) in the near-infrared while maintaining a compact size. When the surface of a gold nanocage is covered with a smart polymer, the pre-loaded effector can be released in a controllable fashion using a near-infrared laser. This system works well with various effectors without involving sophisticated syntheses, and is well suited for in vivo studies owing to the high transparency of soft tissue in the near-infrared region.",
"doi": "10.1038/NMAT2564",
"pmcid": "PMC2787748",
"issn": "1476-1122",
"publisher": "Nature Publishing Group",
"publication": "Nature Materials",
"publication_date": "2009-12",
"series_number": "12",
"volume": "8",
"issue": "12",
"pages": "935-939"
},
{
"id": "authors:gv083-a8g94",
"collection": "authors",
"collection_id": "gv083-a8g94",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160711-144101280",
"type": "article",
"title": "Effects of Different Imaging Models on Least-Squares Image Reconstruction Accuracy in Photoacoustic Tomography",
"author": [
{
"family_name": "Zhang",
"given_name": "Jin",
"clpid": "Zhang-Jin"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
},
{
"family_name": "La Rivi\u00e8re",
"given_name": "Patrick J.",
"clpid": "La-Rivi\u00e8re-P-J"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In the classic formulation of photoacoustic tomography (PAT), two distinct descriptions of the imaging model have been employed for developing reconstruction algorithms. We demonstrate that the numerical and statistical properties of unweighted least-squares reconstruction algorithms associated with each imaging model are generally very different. Specifically, some PAT reconstruction algorithms, including many of the iterative algorithms previously explored, do not work directly with the raw measured pressure wavefields, but rather with an integrated data function that is obtained by temporally integrating the photoacoustic wavefield. The integration modifies the statistical distribution of the data, introducing statistical correlations among samples. This change is highly significant for iterative algorithms, many of which explicitly or implicitly seek to minimize a statistical cost function. In this work, we demonstrate that iterative reconstruction by least-squares minimization yields better resolution-noise tradeoffs when working with the raw pressure data than with the integrated data commonly employed. In addition, we demonstrate that the raw-data based approach is less sensitive to certain deterministic errors, such as dc offset errors.",
"doi": "10.1109/TMI.2009.2024082",
"issn": "0278-0062",
"publisher": "IEEE",
"publication": "IEEE Transactions on Medical Imaging",
"publication_date": "2009-11",
"series_number": "11",
"volume": "28",
"issue": "11",
"pages": "1781-1790"
},
{
"id": "authors:y3dvh-22w22",
"collection": "authors",
"collection_id": "y3dvh-22w22",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-104802883",
"type": "article",
"title": "Photoacoustic tomography and sensing in biomedicine",
"author": [
{
"family_name": "Li",
"given_name": "Changhui",
"clpid": "Li-Changhui"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustics has been broadly studied in biomedicine, for both human and small animal tissues. Photoacoustics uniquely combines the absorption contrast of light or radio frequency waves with ultrasound resolution. Moreover, it is non-ionizing and non-invasive, and is the fastest growing new biomedical method, with clinical applications on the way. This review provides a brief recap of recent developments in photoacoustics in biomedicine, from basic principles to applications. The emphasized areas include the new imaging modalities, hybrid detection methods, photoacoustic contrast agents and the photoacoustic Doppler effect, as well as translational research topics.",
"doi": "10.1088/0031-9155/54/19/R01",
"pmcid": "PMC2872141",
"issn": "0031-9155",
"publisher": "IOP Publishing",
"publication": "Physics in Medicine and Biology",
"publication_date": "2009-10-07",
"series_number": "19",
"volume": "54",
"issue": "19",
"pages": "R59-R97"
},
{
"id": "authors:2cdm7-qaq40",
"collection": "authors",
"collection_id": "2cdm7-qaq40",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-134505992",
"type": "article",
"title": "Photoacoustic tomography of small animal brain with a curved array transducer",
"author": [
{
"family_name": "Yang",
"given_name": "Xinmai",
"clpid": "Yang-Xinmai"
},
{
"family_name": "Maurudis",
"given_name": "Anastasios",
"clpid": "Maurudis-A"
},
{
"family_name": "Gamelin",
"given_name": "John",
"clpid": "Gamelin-J"
},
{
"family_name": "Aguirre",
"given_name": "Andres",
"clpid": "Aguirre-A"
},
{
"family_name": "Zhu",
"given_name": "Quing",
"clpid": "Zhu-Quing"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present the application of a curved array photoacoustic tomographic imaging system that can provide rapid, high-resolution photoacoustic imaging of small animal brains. The system is optimized to produce a B-mode, 90-deg field-of-view image at sub-200-\u03bcm resolution at a frame rate of \u223c1frame\u2215second when a 10-Hz pulse repetition rate laser is employed. By rotating samples, a complete 360-deg scan can be achieved within 15s. In previous work, two-dimensional (2-D) ex vivo mouse brain cortex imaging has been reported. We report three-dimensional (3-D) small animal brain imaging obtained with the curved array system. The results are presented as a series of 2-D cross-sectional images. Besides structural imaging, the blood oxygen saturation of the animal brain cortex is also measured in vivo. In addition, the system can measure the time-resolved relative changes in blood oxygen saturation level in the small animal brain cortex. Last, ultrasonic gel coupling, instead of the previously adopted water coupling, is conveniently used in near-real-time 2-D imaging.",
"doi": "10.1117/1.3227035",
"pmcid": "PMC2917457",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2009-09-16",
"series_number": "5",
"volume": "14",
"issue": "5",
"pages": "Art. No. 054007"
},
{
"id": "authors:k2fr8-89q37",
"collection": "authors",
"collection_id": "k2fr8-89q37",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-154206358",
"type": "article",
"title": "Three-dimensional combined photoacoustic and optical coherence microscopy for in vivo microcirculation studies",
"author": [
{
"family_name": "Li",
"given_name": "Li",
"clpid": "Li-Li"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic microscopy is predominantly sensitive to optical absorption, while optical coherence tomography relies on optical backscattering. Integrating their complementary contrasts can provide comprehensive information about biological tissue. We have developed a dual-modality microscope that combines the two for studying microcirculation. Three-dimensional imaging of microvasculature and its local environment has been demonstrated at micrometer-order resolution using endogenous contrast in vivo.",
"doi": "10.1364/OE.17.016450",
"pmcid": "PMC2855548",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "2009-09-14",
"series_number": "19",
"volume": "17",
"issue": "19",
"pages": "16450-16455"
},
{
"id": "authors:ye35x-wqy85",
"collection": "authors",
"collection_id": "ye35x-wqy85",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160706-141016065",
"type": "article",
"title": "Evans blue dye-enhanced capillary-resolution photoacoustic microscopy in vivo",
"author": [
{
"family_name": "Yao",
"given_name": "Junjie",
"clpid": "Yao-Junjie"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Complete and continuous imaging of microvascular networks is crucial for a wide variety of biomedical applications. Photoacoustic tomography can provide high resolution microvascular imaging using hemoglobin within red blood cells (RBCs) as an endogenic contrast agent. However, intermittent RBC flow in capillaries results in discontinuous and fragmentary capillary images. To overcome this problem, we use Evans blue (EB) dye as a contrast agent for in vivo photoacoustic imaging. EB has strong optical absorption and distributes uniformly in the blood stream by chemically binding to albumin. With the help of EB, complete and continuous microvascular networks\u2014especially capillaries\u2014are imaged. The diffusion dynamics of EB leaving the blood stream and the clearance dynamics of the EB-albumin complex are also quantitatively investigated.",
"doi": "10.1117/1.3251044",
"pmcid": "PMC2782364",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2009-09",
"series_number": "5",
"volume": "14",
"issue": "5",
"pages": "Art. No. 054049"
},
{
"id": "authors:adegm-acv74",
"collection": "authors",
"collection_id": "adegm-acv74",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160615-101243947",
"type": "article",
"title": "Multiscale photoacoustic microscopy and computed tomography",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) is probably the fastest-growing area of biomedical imaging technology, owing to its capacity for high-resolution sensing of rich optical contrast in vivo at depths beyond the optical transport mean free path (~1 mm in human skin). Existing high-resolution optical imaging technologies, such as confocal microscopy and two-photon microscopy, have had a fundamental impact on biomedicine but cannot reach the penetration depths of PAT. By utilizing low ultrasonic scattering, PAT indirectly improves tissue transparency up to 1000-fold and consequently enables deeply penetrating functional and molecular imaging at high spatial resolution. Furthermore, PAT promises in vivo imaging at multiple length-scales; it can image subcellular organelles to organs with the same contrast origin \u2014 an important application in multiscale systems biology research.",
"doi": "10.1038/nphoton.2009.157",
"pmcid": "PMC2802217",
"issn": "1749-4885",
"publisher": "Nature Publishing Group",
"publication": "Nature Photonics",
"publication_date": "2009-09",
"series_number": "9",
"volume": "3",
"issue": "9",
"pages": "503-509"
},
{
"id": "authors:gv9c4-47q13",
"collection": "authors",
"collection_id": "gv9c4-47q13",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-153438891",
"type": "article",
"title": "Thermoacoustic and photoacoustic sensing of temperature",
"author": [
{
"family_name": "Pramanik",
"given_name": "Manojit",
"clpid": "Pramanik-M"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present a novel temperature-sensing technique using thermoacoustic and photoacoustic measurements. This noninvasive method has been demonstrated using a tissue phantom to have high temporal resolution and temperature sensitivity. Because both photoacoustic and thermoacoustic signal amplitudes depend on the temperature of the source object, the signal amplitudes can be used to monitor the temperature. A temperature sensitivity of 0.15\u00b0C was obtained at a temporal resolution as short as 2s, taking the average of 20 signals. The deep-tissue imaging capability of this technique can potentially lead us to in vivo temperature monitoring in thermal or cryogenic applications.",
"doi": "10.1117/1.3247155",
"pmcid": "PMC2774978",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2009-09",
"series_number": "5",
"volume": "14",
"issue": "5",
"pages": "Art. No. 054024"
},
{
"id": "authors:4ag54-g9y87",
"collection": "authors",
"collection_id": "4ag54-g9y87",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-102818319",
"type": "article",
"title": "On the speckle-free nature of photoacoustic tomography",
"author": [
{
"family_name": "Guo",
"given_name": "Zijian",
"clpid": "Guo-Zijian"
},
{
"family_name": "Li",
"given_name": "Li",
"clpid": "Li-Li"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Purpose: A long-standing conundrum is why photoacoustic tomography (PAT) possesses the unique ability to produce images devoid of speckle artifacts while all other coherent imaging technologies do not. \n\nMethods: In this paper, we explain the inherent mechanism that suppresses speckle in PAT, and the analysis was validated by simulations based on an experimental PAT system. \n\nResults: We found that the speckle-free feature of PAT results directly from the optical absorption contrast. \n\nConclusions: All optical absorbers expand on laser excitation, and therefore all initial photoacoustic pressure rises are positive, which engenders strong correlations among the photoacoustic waves from the absorbers. As a result, prominent boundaries always build up in photoacousticimages and suppress the interior speckle.",
"doi": "10.1118/1.3187231",
"pmcid": "PMC2738745",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2009-09",
"series_number": "9",
"volume": "36",
"issue": "9",
"pages": "4084-4088"
},
{
"id": "authors:awm1v-nzx26",
"collection": "authors",
"collection_id": "awm1v-nzx26",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160708-094211580",
"type": "article",
"title": "A 3-D High-Frequency Array Based 16 Channel Photoacoustic Microscopy System for In Vivo Micro-Vascular Imaging",
"author": [
{
"family_name": "Bitton",
"given_name": "Rachel",
"clpid": "Bitton-R"
},
{
"family_name": "Zemp",
"given_name": "Roger",
"clpid": "Zemp-R"
},
{
"family_name": "Yen",
"given_name": "Jesse",
"clpid": "Yen-Jesse"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
}
],
"abstract": "This paper discusses the design of a novel photoacoustic microscopy imaging system with promise for studying the structure of tissue microvasculature for applications in visualizing angiogenesis. A new 16 channel analog and digital high-frequency array based photoacoustic microscopy system (PAM) was developed using an Nd: YLF pumped tunable dye laser, a 30 MHz piezo composite linear array transducer, and a custom multichannel receiver electronics system. Using offline delay and sum beam- forming and beamsteering, phantom images were obtained from a 6 \u00b5m carbon fiber in water at a depth of 8 mm. The measured -6 dB lateral and axial spatial resolution of the system was 100 \u00b1 5 \u00b5m and 45 \u00b1 5 \u00b5m, respectively. The dynamic focusing capability of the system was demonstrated by imaging a composite carbon fiber matrix through a 12.5 mm imaging depth. Next, 2-D in vivo images were formed of vessels around 100 \u00b5m in diameter in the human hand. Three-dimensional in vivo images were also formed of micro-vessels 3 mm below the surface of the skin in two Sprague Dawley rats.",
"doi": "10.1109/TMI.2008.2011899",
"pmcid": "PMC2757099",
"issn": "0278-0062",
"publisher": "IEEE",
"publication": "IEEE Transactions on Medical Imaging",
"publication_date": "2009-08",
"series_number": "8",
"volume": "28",
"issue": "8",
"pages": "1190-1197"
},
{
"id": "authors:84fm1-dwg49",
"collection": "authors",
"collection_id": "84fm1-dwg49",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160706-112819316",
"type": "article",
"title": "High-speed dynamic 3D photoacoustic imaging of sentinel lymph node in a murine model using an ultrasound array",
"author": [
{
"family_name": "Song",
"given_name": "Liang",
"clpid": "Song-Liang"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Noninvasive photoacoustic sentinel lymph node (SLN) mapping with high spatial resolution has the potential to improve the false negative rate and eliminate the use of radioactive tracers in SLN identification. In addition, the demonstrated high spatial resolution may enable physicians to replace SLN biopsy with fine needle aspiration biopsy, and thus reduce the risk of associated morbidity. The primary goal of this study is to demonstrate the feasibility of high-speed 3D photoacoustic imaging of the uptake and clearance dynamics of Evans blue dye in SLNs. The photoacoustic imaging system was developed with a 30MHz ultrasound array and a kHz repetition rate laser system. It acquires one 3D photoacousticimage of 166 B-scan frames in 1s, with axial, lateral, and elevational resolutions of 25, 70, and 200\u03bcm, respectively. With optic-fiber based light delivery, the entire system is compact and is convenient to use. Upon injection of Evans blue, a blue dye currently used in clinical SLN biopsy, SLNs in mice and rats were accurately and noninvasively mapped in vivo using our imaging system. In our experiments, the SLNs were found to be located at \u223c0.65mm below the skin surface in mice and \u223c1.2mm in rats. In some cases, lymph vessels and lymphatic valves were also imaged. The dye dynamics\u2014accumulation and clearance\u2014in SLNs were quantitatively monitored by sequential 3D imaging with temporal resolution of as high as \u223c6s. The demonstrated capability suggests that high-speed 3D photoacoustic imaging should facilitate the understanding of the dynamics of various dyes in SLNs and potentially help identify SLNs with high accuracy.",
"doi": "10.1118/1.3168598",
"pmcid": "PMC2724177",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2009-08",
"series_number": "8",
"volume": "36",
"issue": "8",
"pages": "Art. No. 3724"
},
{
"id": "authors:pbssh-7az09",
"collection": "authors",
"collection_id": "pbssh-7az09",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160706-142746934",
"type": "article",
"title": "Nanoparticles for photoacoustic imaging",
"author": [
{
"family_name": "Yang",
"given_name": "Xinmai",
"clpid": "Yang-Xinmai"
},
{
"family_name": "Stein",
"given_name": "Erich W.",
"clpid": "Stein-E-W"
},
{
"family_name": "Ashkenazi",
"given_name": "S.",
"clpid": "Ashkenazi-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Nanoparticles have been designed and applied as contrast enhancers in various optical imaging techniques, such as optical coherence tomography, fluorescence imaging, and optical reflectance microscopy. As an emerging hybrid imaging modality, photoacoustic imaging (PAI) has also benefited from the application of these nanoparticle-based contrast agents. We review this rapidly growing field and describe the applications of nanoparticles in PAI. Particular focus is given to nanoparticles whose absorption mechanism is based on surface plasmon resonance, including gold nanoshells, nanorods, and nanocages. Dye-embedded nanoparticles are also reviewed. Specifically, the design and application of each nanoparticle-based contrast agent in relation to the field of PAI are detailed.",
"doi": "10.1002/wnan.42",
"issn": "1939-5116",
"publisher": "Wiley",
"publication": "Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology",
"publication_date": "2009-07",
"series_number": "4",
"volume": "1",
"issue": "4",
"pages": "360-368"
},
{
"id": "authors:6yh3c-0s569",
"collection": "authors",
"collection_id": "6yh3c-0s569",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200226-093155050",
"type": "article",
"title": "Preliminary Study on Skin Cancer Detection in Sencar Mice Using Mueller Optical Coherence Tomography",
"author": [
{
"family_name": "Todorovi\u0107",
"given_name": "Milo\u0161",
"clpid": "Todorovi\u0107-M"
},
{
"family_name": "Jiao",
"given_name": "Shuliang",
"clpid": "Jiao-Shuliang"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We report on the use of a fiber-based Mueller-matrix optical coherence tomography (OCT) system with continuous source-polarization modulation for in vivo imaging of early stages of skin cancer in SENCAR mice. A homemade hand-held probe with integrated optical scanning and beam delivering optics was coupled in the sample arm. The OCT images show the morphological changes in skin resulting from pre-cancerous papilloma formations that are consistent with histology, thus demonstrating the system's potential for early skin cancer detection.",
"doi": "10.1142/s1793545809000577",
"issn": "1793-5458",
"publisher": "World Scientific Publishing",
"publication": "Journal of Innovative Optical Health Sciences",
"publication_date": "2009-07",
"series_number": "3",
"volume": "2",
"issue": "3",
"pages": "289-294"
},
{
"id": "authors:a6ff4-g4f50",
"collection": "authors",
"collection_id": "a6ff4-g4f50",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160920-160445234",
"type": "article",
"title": "Functional transcranial brain imaging by optical-resolution photoacoustic microscopy",
"author": [
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Tsytsarev",
"given_name": "Vassiliy",
"clpid": "Tsytsarev-V"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical-resolution photoacoustic microscopy (OR-PAM) is applied to functional brain imaging in living mice. A near-diffraction-limited bright-field optical illumination is employed to achieve micrometer lateral resolution, and a dual-wavelength measurement is utilized to extract the blood oxygenation information. The variation in hemoglobin oxygen saturation (sO_2) along vascular branching has been imaged in a precapillary arteriolar tree and a postcapillary venular tree, respectively. To the best of our knowledge, this is the first report on in vivo volumetric imaging of brain microvascular morphology and oxygenation down to single capillaries through intact mouse skulls. It is anticipated that: (i) chronic imaging enabled by this minimally invasive procedure will advance the study of cortical plasticity and neurological diseases; (ii) revealing the neuroactivity-dependent changes in hemoglobin concentration and oxygenation will facilitate the understanding of neurovascular coupling at the capillary level; and (iii) combining functional OR-PAM and high-resolution blood flowmetry will have the potential to explore cellular pathways of brain energy metabolism.",
"doi": "10.1117/1.3194136",
"pmcid": "PMC2855841",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2009-07",
"series_number": "4",
"volume": "14",
"issue": "4",
"pages": "Art. No. 040503"
},
{
"id": "authors:g7nhj-gnp28",
"collection": "authors",
"collection_id": "g7nhj-gnp28",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160920-153732241",
"type": "article",
"title": "A real-time photoacoustic tomography system for small animals",
"author": [
{
"family_name": "Gamelin",
"given_name": "John",
"clpid": "Gamelin-J"
},
{
"family_name": "Maurudis",
"given_name": "Anastasios",
"clpid": "Maurudis-A"
},
{
"family_name": "Aguirre",
"given_name": "Andres",
"clpid": "Aguirre-A"
},
{
"family_name": "Huang",
"given_name": "Fei",
"clpid": "Huang-Fei"
},
{
"family_name": "Guo",
"given_name": "Puyun",
"clpid": "Guo-Puyun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Zhu",
"given_name": "Quing",
"clpid": "Zhu-Quing"
}
],
"abstract": "A real-time 512-element photoacoustic tomography system for small animal imaging using a ring ultrasound array has been developed. The system, based upon a 5 MHz transducer array formed along a 50 mm circular aperture, achieves sub-200 micron lateral resolution over a 2 cm disk-shaped region. Corresponding elevation resolutions of 0.6 to 2.5 mm over the central volume enable depth-resolved 3D tomographic imaging with linear translation. Using 8:1 electronic multiplexing, imaging at up to 8 frame/sec is demonstrated for both dynamic phantoms and in vivo mouse and brain samples. The real-time, full 2D tomographic capability of the system paves the way for functional photoacoustic tomographic imaging studies in small animals with sub-second time frame.",
"doi": "10.1364/OE.17.010489",
"pmcid": "PMC2757438",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "2009-06-22",
"series_number": "13",
"volume": "17",
"issue": "13",
"pages": "10489-10498"
},
{
"id": "authors:6qvqy-m1b92",
"collection": "authors",
"collection_id": "6qvqy-m1b92",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-103418975",
"type": "article",
"title": "Optical fluence distribution study in tissue in dark-field confocal photoacoustic microscopy using a modified Monte Carlo convolution method",
"author": [
{
"family_name": "Xie",
"given_name": "Zhixing",
"clpid": "Xie-Zhixing"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Zhang",
"given_name": "Hao F.",
"clpid": "Zhang-Hao-F"
}
],
"abstract": "We have modified the existing convolution method of the Monte Carlo simulation for finite photon beams with both translational and rotational invariance. The modified convolution method was applied to simulate the optical fluence distribution in tissue in dark-field confocal photoacoustic microscopy. We studied the influence of the size of the dark field and the illumination incident angle on the depth position of the effective optical focus (the region with the highest fluence) and the fluence ratio (the ratio of the optical fluence at the effective optical focus inside the tissue to the optical fluence on the tissue surface along the ultrasonic axis). Within the reach of diffuse photons, the depth position of the effective optical focus increases with the size of the dark field and is much less sensitive to the incident angle. The findings show that, while the fluence at the effective optical focus decreases, the fluence ratio increases with the size of the dark field. The incident angle has a weaker influence on the fluence ratio than the size of the dark field does. An incident angle between 30 and 50 degrees gives the highest fluence at the effective optical focus.",
"doi": "10.1364/AO.48.003204",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2009-06-10",
"series_number": "17",
"volume": "48",
"issue": "17",
"pages": "3204-3211"
},
{
"id": "authors:31awk-nn985",
"collection": "authors",
"collection_id": "31awk-nn985",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-074907418",
"type": "article",
"title": "In vivo carbon nanotube-enhanced non-invasive photoacoustic mapping of the sentinel lymph node",
"author": [
{
"family_name": "Pramanik",
"given_name": "Manojit",
"clpid": "Pramanik-M"
},
{
"family_name": "Song",
"given_name": "Kwang Hyun",
"clpid": "Song-Kwang-Hyun"
},
{
"family_name": "Swierczewska",
"given_name": "Magdalena",
"clpid": "Swierczewska-M"
},
{
"family_name": "Green",
"given_name": "Danielle",
"clpid": "Green-D"
},
{
"family_name": "Sitharaman",
"given_name": "Balaji",
"clpid": "Sitharaman-B"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Sentinel lymph node biopsy (SLNB), a less invasive alternative to axillary lymph node dissection (ALND), has become the standard of care for patients with clinically node-negative breast cancer. In SLNB, lymphatic mapping with radio-labeled sulfur colloid and/or blue dye helps identify the sentinel lymph node (SLN), which is most likely to contain metastatic breast cancer. Even though SLNB, using both methylene blue and radioactive tracers, has a high identification rate, it still relies on an invasive surgical procedure, with associated morbidity. In this study, we have demonstrated a non-invasive single-walled carbon nanotube (SWNT)-enhanced photoacoustic (PA) identification of SLN in a rat model. We have successfully imaged the SLN in vivo by PA imaging (793 nm laser source, 5 MHz ultrasonic detector) with high contrast-to-noise ratio (=89) and good resolution (~500 \u00b5m). The SWNTs also show a wideband optical absorption, generating PA signals over an excitation wavelength range of 740\u2013820 nm. Thus, by varying the incident light wavelength to the near infrared region, where biological tissues (hemoglobin, tissue pigments, lipids and water) show low light absorption, the imaging depth is maximized. In the future, functionalization of the SWNTs with targeting groups should allow the molecular imaging of breast cancer.",
"doi": "10.1088/0031-9155/54/11/001",
"pmcid": "PMC2732197",
"issn": "0031-9155",
"publisher": "IOP Publishing",
"publication": "Physics in Medicine and Biology",
"publication_date": "2009-06-07",
"series_number": "11",
"volume": "54",
"issue": "11",
"pages": "3291-3301"
},
{
"id": "authors:wd9tg-ws330",
"collection": "authors",
"collection_id": "wd9tg-ws330",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-075746970",
"type": "article",
"title": "In vivo functional chronic imaging of a small animal model using optical-resolution photoacoustic microscopy",
"author": [
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical-resolution photoacousticmicroscopy (OR-PAM) has been validated as a valuable tool for label-free volumetric microvascular imaging. More importantly, the advantages of noninvasiveness and measurement consistency suggest the use of OR-PAM for chronic imaging of intact microcirculation. Here, such chronic imaging is demonstrated for the first time by monitoring the healing process of laser-induced microvascular lesions in a small animal model in vivo. The central part of a 1 mm by 1 mm region in a nude mouse ear was treated under a continuous-wave laser to create a microvascular lesion for chronic study. The region of interest was imaged before the laser treatment, immediately after the treatment, and throughout the healing process using both the authors' OR-PAM system and a commercial transmission-mode optical microscope. Three-dimensional microvascular morphology and blood oxygenation information were imaged simultaneously at capillary-level resolution. Transmission-mode optical microscopic images were acquired for comparison. OR-PAM has potential important applications in microcirculatory physiology or pathophysiology, tumor angiogenesis, laser microsurgery, and neuroscience.",
"doi": "10.1118/1.3137572",
"pmcid": "PMC2719493",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2009-06",
"series_number": "6",
"volume": "36",
"issue": "6",
"pages": "2320-2323"
},
{
"id": "authors:4a2q6-qbf58",
"collection": "authors",
"collection_id": "4a2q6-qbf58",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-091358523",
"type": "article",
"title": "Measuring the Optical Absorption Cross Sections of Au\u2212Ag Nanocages and Au Nanorods by Photoacoustic Imaging",
"author": [
{
"family_name": "Cho",
"given_name": "Eun Chul",
"clpid": "Cho-Eun-Chul"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Zhou",
"given_name": "Fei",
"clpid": "Zhou-Fei"
},
{
"family_name": "Cobley",
"given_name": "Claire M.",
"clpid": "Cobley-C-M"
},
{
"family_name": "Song",
"given_name": "Kwang Hyun",
"clpid": "Song-Kwang-Hyun"
},
{
"family_name": "Chen",
"given_name": "Jingyi",
"clpid": "Chen-Jingyi"
},
{
"family_name": "Li",
"given_name": "Zhi-Yuhan",
"clpid": "Li-Zhi-Yuhan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
}
],
"abstract": "This paper presents a method for measuring the optical absorption cross sections (\u03c3_a) of Au\u2212Ag nanocages and Au nanorods. The method is based on photoacoustic (PA) imaging, where the detected signal is directly proportional to the absorption coefficient (\u03bc_a) of the nanostructure. For each type of nanostructure, we first obtained \u03bc_a from the PA signal by benchmarking against a linear calibration curve (PA signal versus \u03bc_a) derived from a set of methylene blue solutions with different concentrations. We then calculated \u03c3_a by dividing the \u03bc_a by the corresponding concentration of the Au nanostructure. Additionally, we obtained the extinction cross section (\u03c3_e, sum of absorption and scattering) from the extinction spectrum recorded using a conventional UV\u2212vis\u2212NIR spectrometer. From the measurements of \u03c3_a and \u03c3_e, we were able to easily derive both the absorption and scattering cross sections for each type of gold nanostructure. The ratios of absorption to extinction obtained from experimental and theoretical approaches agreed well, demonstrating the potential use of this method in determining the optical absorption and scattering properties of gold nanostructures and other types of nanomaterials.",
"doi": "10.1021/jp903343p",
"pmcid": "PMC2695596",
"issn": "1932-7447",
"publisher": "American Chemical Society",
"publication": "Journal of Physical Chemistry C",
"publication_date": "2009-05-28",
"series_number": "21",
"volume": "113",
"issue": "21",
"pages": "9023-9028"
},
{
"id": "authors:ae89j-58262",
"collection": "authors",
"collection_id": "ae89j-58262",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-093359339",
"type": "article",
"title": "Molecular Photoacoustic Tomography with Colloidal Nanobeacons",
"author": [
{
"family_name": "Pan",
"given_name": "Dipanjan",
"clpid": "Pan-Dipanjan"
},
{
"family_name": "Pramanik",
"given_name": "Manojit",
"clpid": "Pramanik-M"
},
{
"family_name": "Senpan",
"given_name": "Angana",
"clpid": "Senpan-A"
},
{
"family_name": "Yang",
"given_name": "Xinmai",
"clpid": "Yang-Xinmai"
},
{
"family_name": "Song",
"given_name": "Kwang H.",
"clpid": "Song-Kwang-H"
},
{
"family_name": "Scott",
"given_name": "Mike J.",
"clpid": "Scott-M-J"
},
{
"family_name": "Zhang",
"given_name": "Huiying",
"clpid": "Zhang-Huiying"
},
{
"family_name": "Gaffney",
"given_name": "Patrick J.",
"clpid": "Gaffney-P-J"
},
{
"family_name": "Wickline",
"given_name": "Samuel A.",
"clpid": "Wickline-S-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Lanza",
"given_name": "Gregory M.",
"clpid": "Lanza-G-M"
}
],
"abstract": "Spotting clots: Vascularly constrained colloidal gold nanobeacons (GNBs; see picture) can be used as exogenous photoacoustic contrast agents for the targeted detection of fibrin, a major biochemical feature of thrombus. Fibrin-targeted GNBs provide a more than tenfold signal enhancement in photoacoustic tomography in the near-IR wavelength window, indicating their potential for diagnostic imaging.",
"doi": "10.1002/anie.200805947",
"pmcid": "PMC2885454",
"issn": "1433-7851",
"publisher": "Wiley",
"publication": "Angewandte Chemie International Edition",
"publication_date": "2009-05-25",
"series_number": "23",
"volume": "48",
"issue": "23",
"pages": "4170-4173"
},
{
"id": "authors:b3sde-8cw50",
"collection": "authors",
"collection_id": "b3sde-8cw50",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-103925134",
"type": "article",
"title": "Photoacoustic endoscopy",
"author": [
{
"family_name": "Yang",
"given_name": "Joon-Mo",
"clpid": "Yang-Joon-Mo"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Yang",
"given_name": "Hao-Chung",
"clpid": "Yang-Hao-Chung"
},
{
"family_name": "Zhou",
"given_name": "Qifa",
"clpid": "Zhou-Qifa"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have developed photoacoustic endoscopy with a miniaturized imaging probe. A light-guiding optical fiber, an ultrasonic sensor, and a mechanical scanning unit are integrated to enable circumferential sector scanning, which produces B-scan images. Biological tissues, including the gastrointestinal tract of a rat, have been imaged ex vivo or in situ.",
"doi": "10.1364/OL.34.001591",
"pmcid": "PMC2738934",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2009-05-15",
"series_number": "10",
"volume": "34",
"issue": "10",
"pages": "1591-1593"
},
{
"id": "authors:aq27d-9b590",
"collection": "authors",
"collection_id": "aq27d-9b590",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160711-105632975",
"type": "article",
"title": "Noninvasive, in vivo imaging of the mouse brain using photoacoustic microscopy",
"author": [
{
"family_name": "Stein",
"given_name": "Erich W.",
"clpid": "Stein-E-W"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Noninvasive, high resolution imaging of mouse brain activity is poised to provide clinically translatable insights into human neurological disease progression. Toward noninvasive imaging of brain activity through the hemodynamic response, the dark-field photoacoustic microscopy (PAM) technique was enhanced to image the cortex vasculature of the mouse brainin vivo using endogenous hemoglobin contrast. Specifically, the PAM system was redesigned to efficiently collect photoacousticwaves originating from cortical vessels, providing high (70\u03bcm lateral and 54 \u03bcm axial) resolution images of the mouse brain vasculature with a contrast-to-noise ratio of 25 dB. These findings confirm the efficacy of PAM to noninvasively image vascular structures in the mouse brain and the potential to image mouse brain function by tracking the hemodynamic response.",
"doi": "10.1063/1.3116134",
"pmcid": "PMC2719465",
"issn": "0021-8979",
"publisher": "American Institute of Physics",
"publication": "Journal of Applied Physics",
"publication_date": "2009-05-15",
"series_number": "10",
"volume": "105",
"issue": "10",
"pages": "Art. No. 102027"
},
{
"id": "authors:nqfdw-8ke18",
"collection": "authors",
"collection_id": "nqfdw-8ke18",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-100634608",
"type": "article",
"title": "Noninvasive in vivo spectroscopic nanorod-contrast photoacoustic mapping of sentinel lymph nodes",
"author": [
{
"family_name": "Song",
"given_name": "Kwang Hyun",
"clpid": "Song-Kwang-Hyun"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Sentinel lymph node (SLN) biopsy has increasingly become important in axillary staging of breast cancer patients since SLN biopsy alleviates the postoperative complications of previously practiced axillary lymph node dissections. Nevertheless, the procedures of SLN biopsy using blue dye and radioactive substance are still intraoperative, and the latter methods are also ionizing. In this pilot study, we have proposed noninvasive in vivo spectroscopic photoacoustic (PA) SLN mapping using gold nanorods as lymph node tracers in a rat model. Gold nanorods have biocompatibility, high optical absorption, and easily tuned surface plasmon resonance peak wavelength.",
"doi": "10.1016/j.ejrad.2009.01.045",
"pmcid": "PMC7015035",
"issn": "0720-048X",
"publisher": "Elsevier",
"publication": "European Journal of Radiology",
"publication_date": "2009-05",
"series_number": "2",
"volume": "70",
"issue": "2",
"pages": "227-231"
},
{
"id": "authors:srbp9-j2154",
"collection": "authors",
"collection_id": "srbp9-j2154",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-140608777",
"type": "article",
"title": "Single-walled carbon nanotubes as a multimodal-thermoacoustic and photoacoustic-contrast agent",
"author": [
{
"family_name": "Pramanik",
"given_name": "Manojit",
"clpid": "Pramanik-M"
},
{
"family_name": "Swierczewska",
"given_name": "Magdalena",
"clpid": "Swierczewska-M"
},
{
"family_name": "Green",
"given_name": "Danielle",
"clpid": "Green-D"
},
{
"family_name": "Sitharaman",
"given_name": "Balaji",
"clpid": "Sitharaman-B"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have developed a novel carbon nanotube-based contrast agent for both thermoacoustic and photoacoustic tomography. In comparison to deionized water, single-walled carbon nanotubes exhibited more than twofold signal enhancement for thermoacoustic tomography at 3GHz. In comparison to blood, they exhibited more than sixfold signal enhancement for photoacoustic tomography at 1064nm wavelength. The large contrast enhancement of single-walled carbon nanotubes was further corroborated by tissue phantom imaging studies.",
"doi": "10.1117/1.3147407",
"pmcid": "PMC2732201",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2009-05",
"series_number": "3",
"volume": "14",
"issue": "3",
"pages": "Art. No. 034018"
},
{
"id": "authors:vj8tg-g5x81",
"collection": "authors",
"collection_id": "vj8tg-g5x81",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-101059178",
"type": "article",
"title": "Noninvasive label-free imaging of microhemodynamics by optical-resolution photoacoustic microscopy",
"author": [
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In vivo microcirculatory imaging facilitates the fundamental understanding of many major diseases. However, existing techniques generally require invasive procedures or exogenous contrast agents, which perturb the intrinsic physiology of the microcirculation. Here, we report on optical-resolution photoacoustic microscopy (OR-PAM) for noninvasive label-free microcirculatory imaging at cellular levels. For the first time, OR-PAM demonstrates quantification of hemoglobin concentration and oxygenation in single microvessels down to capillaries. Using this technique, we imaged several important yet elusive microhemodynamic activities\u2014including vasomotion and vasodilation\u2014in small animals in vivo. OR-PAM enables functional volumetric imaging of the intact microcirculation, thereby providing greatly improved accuracy and versatility for broad biological and clinical applications.",
"doi": "10.1364/OE.17.007688",
"pmcid": "PMC2711847",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "2009-04-27",
"series_number": "9",
"volume": "17",
"issue": "9",
"pages": "7688-7693"
},
{
"id": "authors:sk47m-t3h28",
"collection": "authors",
"collection_id": "sk47m-t3h28",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-092710571",
"type": "article",
"title": "Micromachined \"side-viewing\" optical sensor probe for detection of esophageal cancers",
"author": [
{
"family_name": "Garcia-Uribe",
"given_name": "A.",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Balareddy",
"given_name": "K. C.",
"clpid": "Balareddy-K-C"
},
{
"family_name": "Zou",
"given_name": "J.",
"clpid": "Zou-J"
},
{
"family_name": "Wojcik",
"given_name": "A. K.",
"clpid": "Wojcik-A-K"
},
{
"family_name": "Wang",
"given_name": "K. K.",
"clpid": "Wang-K-K"
},
{
"family_name": "Wang",
"given_name": "L. V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In this paper, we report the design, fabrication and testing of a new miniaturized optical sensor probe with \"side viewing\" capability for oblique incidence diffuse reflectance spectrometry. The sensor probe consists of a lithographically patterned polymer waveguides chip and two micromachined positioning substrates and source/collection fibers to achieve 45\u00b0 light incidence and collection of spatially resolved diffuse reflectance. Diffuse reflectance of human esophageal surface has been successfully measured for differentiation of cancerous tissues from normal ones.",
"doi": "10.1016/j.sna.2008.11.008",
"pmcid": "PMC4286192",
"issn": "0924-4247",
"publisher": "Elsevier",
"publication": "Sensors and Actuators A",
"publication_date": "2009-03-16",
"series_number": "1",
"volume": "150",
"issue": "1",
"pages": "144-150"
},
{
"id": "authors:jrt0b-5wy37",
"collection": "authors",
"collection_id": "jrt0b-5wy37",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-091023722",
"type": "article",
"title": "M-mode photoacoustic particle flow imaging",
"author": [
{
"family_name": "Fang",
"given_name": "Hui",
"clpid": "Fang-Hui"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Recently, there has been growing interest in the development of photoacoustic flow measuring methods aimed to study microvascular blood flow in biological tissue. Here, we describe the M-mode photoacoustic particle flow imaging, using an optical resolution photoacoustic microscope equipped with a high-repetition-rate pulsed dye laser. We studied the flow of a diluted dyed particle suspension in a small tube embedded in a nonscattering medium as well as in a scattering medium simulating biological tissue. Potentially, the method can be applied to detect the flow speed of single red blood cells in a capillary.",
"doi": "10.1364/OL.34.000671",
"pmcid": "PMC6986312",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2009-03-01",
"series_number": "5",
"volume": "34",
"issue": "5",
"pages": "671-673"
},
{
"id": "authors:emtg0-5rw03",
"collection": "authors",
"collection_id": "emtg0-5rw03",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-154951392",
"type": "article",
"title": "Ultrasound-modulated optical tomography in reflection mode with ring-shaped light illumination",
"author": [
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Song",
"given_name": "Kwang Hyun",
"clpid": "Song-Kwang-Hyun"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have succeeded in implementing ring-shaped light illumination ultrasound-modulated optical tomography (UOT) in reflection mode. The system used intense acoustic bursts and a charge-coupled device (CCD) camera-based speckle contrast detection method. In addition, the implementation allows placing the tissue sample below (not within) an acoustic coupling water tank and scanning the tissue without moving the sample. Thus, the UOT system is more clinically applicable than previous transmission-mode systems. Furthermore, we have successfully imaged an ex vivo methylene-blue-dyed sentinel lymph node (SLN) embedded at a depth of 13mm in chicken breast tissue. This UOT system offers several advantages: noninvasiveness, nonionizing radiation, portability, cost effectiveness, and the possibility of combination with ultrasound pulse-echo imaging and photoacoustic imaging. One potential application of the UOT system is mapping SLNs in axillary staging for breast cancer patients.",
"doi": "10.1117/1.3088224",
"pmcid": "PMC2716112",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2009-03",
"series_number": "2",
"volume": "14",
"issue": "2",
"pages": "Art. No. 024015"
},
{
"id": "authors:sb48n-34m15",
"collection": "authors",
"collection_id": "sb48n-34m15",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160920-154512399",
"type": "article",
"title": "Automatic algorithm for skin profile detection in photoacoustic microscopy",
"author": [
{
"family_name": "Zhang",
"given_name": "Hao F.",
"clpid": "Zhang-Hao-F"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have developed an automatic algorithm to detect the skin profiles in the volumetric data acquired by photoacoustic microscopy for subcutaneous vasculature imaging. This algorithm analyzes the relationship between amplitudes of photoacoustic signals generated from the skin surface and underlying blood vessels to achieve a rough estimation of the skin profile. A better approximation of the skin profile is then acquired after nonparametric smoothing and Gaussian low-pass spatial filtering. An auto-fit scan mechanism is further developed based on the detected skin profile to achieve good ultrasonic focusing on the subcutaneous vessel layer when the skin contour variation is much larger than the ultrasonic focal zone. The importance of skin profile detection in calculating the maximum-amplitude-projection images and significantly improving the image quality by employing the auto-fit scan are demonstrated by in vivo experimental results.",
"doi": "10.1117/1.3122362",
"pmcid": "PMC5538579",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2009-03",
"series_number": "2",
"volume": "14",
"issue": "2",
"pages": "Art. No. 024050"
},
{
"id": "authors:843ws-6pk17",
"collection": "authors",
"collection_id": "843ws-6pk17",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-135311246",
"type": "article",
"title": "Photoacoustic tomography of the mouse cerebral cortex with a high-numerical-aperture-based virtual point detector",
"author": [
{
"family_name": "Li",
"given_name": "Changhui",
"clpid": "Li-Changhui"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The mouse cerebral cortex was imaged in situ by photoacoustic tomography (PAT). Instead of a flat ultrasonic transducer, a virtual point detector based on a high numerical aperture (NA), positively focused transducer was used. This virtual point detector has a wide omnidirectional acceptance angle, a high sensitivity, and a negligible aperture effect. In addition, the virtual point detector can be located much more closely to the object during the detection. Compared with a finite-size flat transducer, images generated by using this virtual point detector have both uniform signal-to-noise ratio (SNR) and resolution.",
"doi": "10.1117/1.3122365",
"pmcid": "PMC2858757",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2009-03",
"series_number": "2",
"volume": "14",
"issue": "2",
"pages": "Art. No. 024047"
},
{
"id": "authors:492ak-pr731",
"collection": "authors",
"collection_id": "492ak-pr731",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-152451146",
"type": "article",
"title": "Tangential resolution improvement in thermoacoustic and photoacoustic tomography using a negative acoustic lens",
"author": [
{
"family_name": "Pramanik",
"given_name": "Manojit",
"clpid": "Pramanik-M"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We developed a novel concept of using a negative acoustic lens to increase the acceptance angle of an unfocused large-area ultrasonic transducer (detector), leading to more than twofold improvement of the tangential resolution in both thermoacoustic and photoacoustic tomography. In both thermoacoustic and photoacoustic tomography, for a given transducer bandwidth, the aperture size of the detector affects the tangential resolution greatly when the object of interest is near the detector surface. We were able to overcome such tangential resolution deterioration by attaching an acoustic concave lens, made of acrylic in front of the flat detector surface. We then quantified the tangential resolution improvement using phantom images. We also showed that the use of the negative lens preserves the shape of an object after the image is reconstructed.",
"doi": "10.1117/1.3103778",
"pmcid": "PMC2858381",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2009-03",
"series_number": "2",
"volume": "14",
"issue": "2",
"pages": "Art. No. 024028"
},
{
"id": "authors:cg2s1-qb146",
"collection": "authors",
"collection_id": "cg2s1-qb146",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-102050602",
"type": "article",
"title": "Noninvasive, in vivo imaging of blood-oxygenation dynamics within the mouse brain using photoacoustic microscopy",
"author": [
{
"family_name": "Stein",
"given_name": "Erich W.",
"clpid": "Stein-E-W"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic microscopy (PAM) has been used to obtain high-resolution, noninvasive images of the in vivo mouse brain. In this work, we exploit the high-depth and temporal resolutions of PAM to noninvasively image the blood-oxygenation dynamics of multiple cortex vessels in the mouse brain simultaneously in response to controlled hypoxic and hyperoxic challenges. These results confirm the ability of PAM to track blood oxygenation in the mouse brain, a critical aspect of imaging brain activity through the hemodynamic response.",
"doi": "10.1117/1.3095799",
"pmcid": "PMC2676448",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2009-03",
"series_number": "2",
"volume": "14",
"issue": "2",
"pages": "Art. No. 020502"
},
{
"id": "authors:vh2yy-kv645",
"collection": "authors",
"collection_id": "vh2yy-kv645",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-095657414",
"type": "article",
"title": "Near-Infrared Gold Nanocages as a New Class of Tracers for Photoacoustic Sentinel Lymph Node Mapping on a Rat Model",
"author": [
{
"family_name": "Song",
"given_name": "Kwang Hyun",
"clpid": "Song-Kwang-Hyun"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Cobley",
"given_name": "Claire M.",
"clpid": "Cobley-C-M"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "This work demonstrated the use of Au nanocages as a new class of lymph node tracers for noninvasive photoacoustic (PA) imaging of a sentinel lymph node (SLN). Current SLN mapping methods based on blue dye and/or nanometer-sized radioactive colloid injection are intraoperative due to the need for visual detection of the blue dye and low spatial resolution of Geiger counters in detecting radioactive colloids. Compared to the current methods, PA mapping based on Au nanocages shows a number of attractive features: noninvasiveness, strong optical absorption in the near-infrared region (for deep penetration), and the accumulation of Au nanocages with a higher concentration than the initial solution for the injection. In an animal model, these features allowed us to identify SLNs containing Au nanocages as deep as 33 mm below the skin surface with good contrast. Most importantly, compared to methylene blue Au nanocages can be easily bioconjugated with antibodies for targeting specific receptors, potentially eliminating the need for invasive axillary staging procedures in addition to providing noninvasive SLN mapping.",
"doi": "10.1021/nl802746w",
"pmcid": "PMC6986311",
"issn": "1530-6984",
"publisher": "American Chemical Society",
"publication": "Nano Letters",
"publication_date": "2009-01-14",
"series_number": "1",
"volume": "9",
"issue": "1",
"pages": "183-188"
},
{
"id": "authors:6cwzd-h2257",
"collection": "authors",
"collection_id": "6cwzd-h2257",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160920-155920828",
"type": "article",
"title": "Ex vivo blood vessel imaging using ultrasound-modulated optical microscopy",
"author": [
{
"family_name": "Kothapalli",
"given_name": "Sri-Rajasekhar",
"clpid": "Kothapalli-S-R"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Recently we developed ultrasound-modulated optical microscopy (UOM) based on a long-cavity confocal Fabry-Perot interferometer (CFPI). This interferometer is used for real-time detection of multiply scattered light modulated by high frequency (30to75MHz) ultrasound pulses propagating in an optically, strongly scattering medium. In this work, we use this microscope to study the dependence of ultrasound-modulated optical signals on the optical absorption and scattering properties of objects embedded about 3mm deep in tissue mimicking phantoms. These results demonstrate that UOM has the potential to map both optical absorption and scattering contrast. Most importantly, for the first time in the field of ultrasound-modulated optical imaging, we image blood vasculature in highly scattering tissue samples from a mouse and a rat. Therefore, UOM could be a promising tool to study the morphology of blood vasculature and blood-associated functional parameters, such as oxygen saturation.",
"doi": "10.1117/1.3076191",
"pmcid": "PMC4291120",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2009-01",
"series_number": "1",
"volume": "14",
"issue": "1",
"pages": "Art. No. 014015"
},
{
"id": "authors:3gq7d-1ha25",
"collection": "authors",
"collection_id": "3gq7d-1ha25",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-080603616",
"type": "article",
"title": "In-vivo photoacoustic microscopy of nanoshell extravasation from solid tumor vasculature",
"author": [
{
"family_name": "Li",
"given_name": "Meng-Lin",
"clpid": "Li-Meng-Lin"
},
{
"family_name": "Wang",
"given_name": "James Chunjay",
"clpid": "Wang-James-Chunjay"
},
{
"family_name": "Schwartz",
"given_name": "Jon A.",
"clpid": "Schwartz-J-A"
},
{
"family_name": "Gill-Sharp",
"given_name": "Kelly L.",
"clpid": "Gill-Sharp-K-L"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In this study, high resolution backward-mode photoacoustic microscopy (PAM) is used to noninvasively image progressive extravasation and accumulation of nanoshells within a solid tumor in vivo. PAM takes advantage of the strong near-infrared absorption of nanoshells and their extravasation tendency from leaky tumor vasculatures for imaging. Subcutaneous tumors are grown on immunocompetent BALB/c mice. Polyethylene glycol (PEGylated) nanoshells with a peak optical absorption at \u223c800nm are intravenously administered. With an 800-nm laser source, a prescan prior to nanoshell injection is taken to determine the background that is free of nanoshell accumulation. After injection, the 3-D nanoshell distribution at the tumor foci is monitored by PAM for 6h. Experimental results show that accumulated nanoshells delineate the tumor position. Nanoshell accumulation is heterogeneous in tumors: more concentrated within the tumor cortex and largely absent from the tumor core. Because nanoshells have been recently demonstrated to enhance thermal therapy of subcutaneous tumors, we anticipate that PAM will be an important aid before, during, and after nanoshell thermal therapy.",
"doi": "10.1117/1.3081556",
"pmcid": "PMC6988903",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2009-01",
"series_number": "1",
"volume": "14",
"issue": "1",
"pages": "Art. No. 010507"
},
{
"id": "authors:8rwne-5ae18",
"collection": "authors",
"collection_id": "8rwne-5ae18",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160921-155919948",
"type": "article",
"title": "Adaptive and Robust Methods of Reconstruction (ARMOR) for Thermoacoustic Tomography",
"author": [
{
"family_name": "Xie",
"given_name": "Yao",
"clpid": "Xie-Yao"
},
{
"family_name": "Guo",
"given_name": "Bin",
"clpid": "Guo-Bin"
},
{
"family_name": "Liu",
"given_name": "Jian",
"orcid": "0000-0001-8552-1400",
"clpid": "Liu-Jian"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In this paper, we present new adaptive and robust methods of reconstruction (ARMOR) for thermoacoustic tomography (TAT), and study their performances for breast cancer detection. TAT is an emerging medical imaging technique that combines the merits of high contrast due to electromagnetic or laser stimulation and high resolution offered by thermal acoustic imaging. The current image reconstruction methods used for TAT, such as the delay-and-sum (DAS) approach, are data-independent and suffer from low-resolution, high sidelobe levels, and poor interference rejection capabilities. The data-adaptive ARMOR can have much better resolution and much better interference rejection capabilities than their data-independent counterparts. By allowing certain uncertainties, ARMOR can be used to mitigate the amplitude and phase distortion problems encountered in TAT. The excellent performance of ARMOR is demonstrated using both simulated and experimentally measured data.",
"doi": "10.1109/TBME.2008.919112",
"issn": "0018-9294",
"publisher": "IEEE",
"publication": "IEEE Transactions on Biomedical Engineering",
"publication_date": "2008-12",
"series_number": "12",
"volume": "55",
"issue": "12",
"pages": "2741-2752"
},
{
"id": "authors:q99pe-vxx22",
"collection": "authors",
"collection_id": "q99pe-vxx22",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160608-154817606",
"type": "article",
"title": "Prospects of photoacoustic tomography",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Commercially available high-resolution three-dimensional optical imaging modalities\u2014including confocal microscopy, two-photon microscopy, and optical coherence tomography\u2014have fundamentally impacted biomedicine. Unfortunately, such tools cannot penetrate biological tissue deeper than the optical transport mean free path (\u223c1mm in the skin). Photoacoustictomography, which combines strong optical contrast and high ultrasonic resolution in a single modality, has broken through this fundamental depth limitation and achieved superdepth high-resolution optical imaging. In parallel, radio frequency-or microwave-induced thermoacoustic tomography is being actively developed to combine radio frequency or microwave contrast with ultrasonic resolution. In this Vision 20/20 article, the prospects of photoacoustictomography are envisaged in the following aspects: (1) photoacoustic microscopy of optical absorption emerging as a mainstream technology, (2) melanoma detection using photoacoustic microscopy, (3) photoacoustic endoscopy, (4) simultaneous functional and molecular photoacoustictomography, (5) photoacoustictomography of gene expression, (6) Doppler photoacoustictomography for flow measurement, (7) photoacoustictomography of metabolic rate of oxygen, (8) photoacoustic mapping of sentinel lymph nodes, (9) multiscale photoacoustic imagingin vivo with common signal origins, (10) simultaneous photoacoustic and thermoacoustic tomography of the breast, (11) photoacoustic and thermoacoustic tomography of the brain, and (12) low-background thermoacoustic molecular imaging.",
"doi": "10.1118/1.3013698",
"pmcid": "PMC2647010",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2008-12",
"series_number": "12",
"volume": "35",
"issue": "12",
"pages": "5758-5767"
},
{
"id": "authors:0qcva-xe732",
"collection": "authors",
"collection_id": "0qcva-xe732",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160927-121109607",
"type": "article",
"title": "Realtime Photoacoustic Microscopy of Murine Cardiovascular Dynamics",
"author": [
{
"family_name": "Zemp",
"given_name": "R. J.",
"clpid": "Zemp-R-J"
},
{
"family_name": "Song",
"given_name": "L.",
"clpid": "Song-L"
},
{
"family_name": "Bitton",
"given_name": "R.",
"clpid": "Bitton-R"
},
{
"family_name": "Shung",
"given_name": "K. K.",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Wang",
"given_name": "L. V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Non-invasive visualization of cardiovascular dynamics in small animals is challenging due to their rapid heart-rates. We present a realtime photoacoustic imaging system consisting of a 30-MHz ultrasound array transducer, receive electronics, a high-repetition-rate laser, and a multicore-computer, and demonstrate its ability to image optically-absorbing structures of the beating hearts of young athymic nude mice at rates of ~50 frames per second with 100 \u00b5m\u00d725 \u00b5m spatial resolution. To our knowledge this is the first report of realtime photoacoustic imaging of physiological dynamics.",
"doi": "10.1364/OE.16.018551",
"pmcid": "PMC2644743",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "2008-10-27",
"series_number": "22",
"volume": "16",
"issue": "22",
"pages": "18551-18556"
},
{
"id": "authors:agza6-q3r35",
"collection": "authors",
"collection_id": "agza6-q3r35",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160923-140140684",
"type": "article",
"title": "Micromachined Fiber Optical Sensor for In Vivo Measurement of Optical Properties of Human Skin",
"author": [
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Balareddy",
"given_name": "Karthik Chinna",
"clpid": "Balareddy-K-C"
},
{
"family_name": "Zou",
"given_name": "Jun",
"orcid": "0000-0002-9543-6135",
"clpid": "Zou-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In this paper, we present the design, fabrication, and testing of a new micromachined fiber optic sensor probe to conduct oblique incidence diffuse reflectance spectrometry (OIDRS) for in vivo estimation of optical properties of human skins. The probe consists of three source fibers, two linear array of collection fibers, and four micromachined positioning devices for accurate alignment of the fibers. Micromachining plays a significant role in the probe development by enabling device miniaturization, low-cost fabrication, and precise assembly. The new probe has been successfully used to estimate the absorption and scattering coefficient spectra of skin with an optical spectrum between 455 and 765 nm.",
"doi": "10.1109/JSEN.2008.2003306",
"issn": "1530-437X",
"publisher": "IEEE",
"publication": "IEEE Sensors Journal",
"publication_date": "2008-10",
"series_number": "10",
"volume": "8",
"issue": "10",
"pages": "1698-1703"
},
{
"id": "authors:bx58n-84131",
"collection": "authors",
"collection_id": "bx58n-84131",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160926-084414294",
"type": "article",
"title": "Noninvasive photoacoustic imaging of the thoracic cavity and the kidney in small and large animals",
"author": [
{
"family_name": "Song",
"given_name": "Kwang Hyun",
"clpid": "Song-Kwang-Hyun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The internal organs of rats and rabbits were clearly imaged noninvasively using a deeply penetrating reflection-mode photoacoustic imagingsystem. This imagingsystem had previously been found to provide an imaging depth limit of \u223c38mm. In the thoracic cavity, major blood vessels connecting to the heart were imaged, and the right atrium was imaged as deeply as \u223c8mm. In the abdominal cavities, the kidney and vena cava inferior were also imagedin situ. The vena cava inferior \u223c13.7mm deep was imaged. The kidney of a New Zealand white rabbit was also imaged. This study shows the deep internal organimaging capability of the system in animals. This technology can potentially be used to study tumors in internal organs, and be adapted to clinical diagnosis.",
"doi": "10.1118/1.2977534",
"pmcid": "PMC2673591",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2008-10",
"series_number": "10",
"volume": "35",
"issue": "10",
"pages": "4524-4529"
},
{
"id": "authors:s6qsm-jvs73",
"collection": "authors",
"collection_id": "s6qsm-jvs73",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200226-105436123",
"type": "article",
"title": "Simultaneous imaging of a lacZ-marked tumor and microvasculature morphology in vivo by dual-wavelength photoacoustic microscopy",
"author": [
{
"family_name": "Li",
"given_name": "Li",
"clpid": "Li-Li"
},
{
"family_name": "Zhang",
"given_name": "Hao F.",
"clpid": "Zhang-Hao-F"
},
{
"family_name": "Zemp",
"given_name": "Roger J.",
"clpid": "Zemp-R-J"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic molecular imaging, combined with the reporter-gene technique, can provide a valuable tool for cancer research. The expression of the lacZ reporter gene can be imaged using photoacoustic imaging following the injection of X-gal, a colorimetric assay for the lacZ-encoded enzyme \u03b2-galactosidase. Dual-wavelength photoacoustic microscopy was used to non-invasively image the detailed morphology of a lacZ-marked 9L gliosarcoma and its surrounding microvasculature simultaneously in vivo, with a superior resolution on the order of 10 \u03bcm. Tumor-feeding vessels were found, and the expression level of lacZ in tumor was estimated. With future development of new absorption-enhancing reporter-gene systems, we anticipate this strategy can lead to a better understanding of the role of tumor metabolism in cancer initiation, progression, and metastasis, and in its response to therapy.",
"doi": "10.1142/s1793545808000212",
"pmcid": "PMC2782593",
"issn": "1793-5458",
"publisher": "World Scientific Publishing",
"publication": "Journal of Innovative Optical Health Sciences",
"publication_date": "2008-10",
"series_number": "2",
"volume": "1",
"issue": "2",
"pages": "207-215"
},
{
"id": "authors:akaxe-7me13",
"collection": "authors",
"collection_id": "akaxe-7me13",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160608-155254271",
"type": "article",
"title": "Photoacoustic microscopy at super depths",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Combining light and ultrasound in a single hybrid technology enables\nmultiscale, high-resolution imaging deep into biological tissue.",
"doi": "10.1117/2.1200809.1277",
"issn": "1818-2259",
"publisher": "SPIE",
"publication": "SPIE Newsroom",
"publication_date": "2008-09-22",
"pages": "Art. No. 1277"
},
{
"id": "authors:bvyhv-k7e81",
"collection": "authors",
"collection_id": "bvyhv-k7e81",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160922-140950991",
"type": "article",
"title": "Detection of ultrasound-modulated diffuse photons using spectral-hole burning",
"author": [
{
"family_name": "Li",
"given_name": "Youzhi",
"clpid": "Li-Youzhi"
},
{
"family_name": "Hemmer",
"given_name": "Philip",
"clpid": "Hemmer-P-R"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Zhang",
"given_name": "Huiliang",
"clpid": "Zhang-Huiliang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The lack of efficient detection techniques has so far prevented ultrasound-modulated optical tomography from achieving maturity. By applying a quantum spectral filter based on spectral-hole burning, one modulation sideband of the ultrasound-modulated diffuse photons can be efficiently selected while the DC and the other sidebands are blocked. This technique features a large etendue as well as the capability of processing numerous speckles in parallel. It is also immune to speckle decorrelation, potentially allowing real-time in vivo imaging. Both theory and experiments are presented.",
"doi": "10.1364/OE.16.014862",
"pmcid": "PMC2596757",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "2008-09-15",
"series_number": "19",
"volume": "16",
"issue": "19",
"pages": "14862-14874"
},
{
"id": "authors:8vjkj-5g446",
"collection": "authors",
"collection_id": "8vjkj-5g446",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160926-081650513",
"type": "article",
"title": "Noninvasive photoacoustic identification of sentinel lymph nodes containing methylene blue in vivo in a rat model",
"author": [
{
"family_name": "Song",
"given_name": "Kwang Hyun",
"clpid": "Song-Kwang-Hyun"
},
{
"family_name": "Stein",
"given_name": "Erich W.",
"clpid": "Stein-E-W"
},
{
"family_name": "Margenthaler",
"given_name": "Julie A.",
"clpid": "Margenthaler-J-A"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Sentinel lymph node biopsy (SLNB) has become the standard method of axillary staging for patients with breast cancer and clinically negative axillae. Even though SLNB using both methylene blue and radioactive tracers has a high identification rate, it still relies on an invasive surgical procedure with associated morbidity. Axillary ultrasound has emerged as a diagnostic tool to evaluate the axilla, but it can only assess morphology and cannot specifically identify sentinel lymph nodes (SLNs). In this pilot study, we propose a noninvasive photoacoustic SLN identification system using methylene blue injection in a rat model. We successfully image a SLN with high optical contrast (146\u00b141, standard deviation) and good ultrasonic resolution (\u223c500\u03bcm) in vivo. We also show potential feasibility for clinical applications by imaging 20- and 31-mm-deep SLNs in 3-D and 2-D, respectively. Our results suggest that this technology would be a useful clinical tool, allowing clinicians to identify SLNs noninvasively in vivo.",
"doi": "10.1117/1.2976427",
"pmcid": "PMC2725003",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2008-09",
"series_number": "5",
"volume": "13",
"issue": "5",
"pages": "Art. No. 054033"
},
{
"id": "authors:tp02v-nyh75",
"collection": "authors",
"collection_id": "tp02v-nyh75",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160923-110234128",
"type": "article",
"title": "Fast 3-D dark-field reflection-mode photoacoustic microscopy in vivo with a 30-MHz ultrasound linear array",
"author": [
{
"family_name": "Song",
"given_name": "Liang",
"clpid": "Song-Liang"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Bitton",
"given_name": "Rachel",
"clpid": "Bitton-R"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present an in vivo dark-field reflection-mode photoacoustic microscopy system that performs cross-sectional (B-scan) imaging at 50Hz with real-time beamforming and 3-D imaging consisting of 166 B-scan frames at 1Hz with postbeamforming. To our knowledge, this speed is currently the fastest in photoacoustic imaging. A custom-designed light delivery system is integrated with a 30-MHz ultrasound linear array to realize dark-field reflection-mode imaging. Linear mechanical scanning of the array produces 3-D images. The system has axial, lateral, and elevational resolutions of 25, 70, and 200\u03bcm, respectively, and can image 3mm deep in scattering biological tissues. Volumetric images of subcutaneous vasculature in rats are demonstrated in vivo. Fast 3-D photoacoustic microscopy is anticipated to facilitate applications of photoacoustic imaging in biomedical studies that involve dynamics and clinical procedures that demand immediate diagnosis.",
"doi": "10.1117/1.2976141",
"pmcid": "PMC2644744",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2008-09",
"series_number": "5",
"volume": "13",
"issue": "5",
"pages": "Art. No. 054028"
},
{
"id": "authors:8t55n-19261",
"collection": "authors",
"collection_id": "8t55n-19261",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160927-143539396",
"type": "article",
"title": "Ultrasound-modulated optical microscopy",
"author": [
{
"family_name": "Kothapalli",
"given_name": "Sri-Rajasekhar",
"clpid": "Kothapalli-S-R"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We demonstrate that microscopic imaging is feasible in ultrasound-modulated optical tomography (UOT) of soft biological tissues, using a high-frequency focused ultrasound transducer with a 75-MHz central frequency. Our experiments in tissue mimicking phantoms show that at an imaging depth of about 2mm, an axial resolution better than 30\u03bcm can be achieved, whereas the lateral resolution is 38\u03bcm. A long-cavity scanning confocal Fabry-Perot interferometer (CFPI) is used for real-time detection of multiply scattered light modulated by high-frequency ultrasound pulses propagating in an optically scattering medium. We also compare the performances of various high-frequency focused ultrasound transducers with central frequencies of 15MHz, 30MHz, 50MHz, and 75MHz. The comparison is based on two-dimensional (2-D) images of optically absorbing objects positioned at a few millimeters depth below the surface of both optically scattering phantoms and soft biological tissue samples. Our experimental results show that modulation depth and image contrast decrease with an increase in ultrasound frequency. In addition, we use analytical calculations to show that modulation depth decreases with increasing ultrasound frequency.",
"doi": "10.1117/1.2983671",
"pmcid": "PMC5522811",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2008-09",
"series_number": "5",
"volume": "13",
"issue": "5",
"pages": "Art. No. 054046"
},
{
"id": "authors:pskxb-yy786",
"collection": "authors",
"collection_id": "pskxb-yy786",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160923-155924471",
"type": "article",
"title": "Negative lens concept for photoacoustic tomography",
"author": [
{
"family_name": "Li",
"given_name": "Changhui",
"clpid": "Li-Changhui"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Although a small point ultrasound transducer has a wide acceptance angle, its small active area leads to a high thermal-noise-induced electric voltage in the transducer, thus the sensitivity is low. By contrast, a finite-size flat transducer has high sensitivity, but the acceptance angle is small, which limits its application in reconstruction-based photoacoustic tomography (PAT). Here, we propose a negative lens concept to increase the acceptance angle of a flat transducer without losing sensitivity. Phantom experiments demonstrate that use of this concept greatly increases the detection region for PAT with high sensitivity.",
"doi": "10.1103/PhysRevE.78.021901",
"pmcid": "PMC2602847",
"issn": "1539-3755",
"publisher": "American Physical Society",
"publication": "Physical Review E",
"publication_date": "2008-08",
"series_number": "2",
"volume": "78",
"issue": "2",
"pages": "Art. No. 021901"
},
{
"id": "authors:wwg6y-8wv61",
"collection": "authors",
"collection_id": "wwg6y-8wv61",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160923-124341481",
"type": "article",
"title": "High-numerical-aperture-based virtual point detectors for photoacoustic tomography",
"author": [
{
"family_name": "Li",
"given_name": "Changhui",
"clpid": "Li-Changhui"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The focal point of a high-numerical-aperture (NA) ultrasonic transducer can be used as a virtual point detector. This virtual point detector detects omnidirectionally over a wide acceptance angle. It also combines a large active transducer surface and a small effective virtual detector size. Thus the sensitivity is high compared with that of a real point detector, and the aperture effect is small compared with that of a finite size transducer. We present two kinds of high-NA-based virtual point detectors and their successful application in photoacoustic tomography. They can also be applied in other ultrasound-related fields.",
"doi": "10.1063/1.2963365",
"pmcid": "PMC2542881",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2008-07-21",
"series_number": "3",
"volume": "93",
"issue": "3",
"pages": "Art. No. 033902"
},
{
"id": "authors:cs86g-d7022",
"collection": "authors",
"collection_id": "cs86g-d7022",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160927-104924888",
"type": "article",
"title": "Pulsed ultrasound-modulated optical tomography using spectral-hole burning as a narrowband spectral filter",
"author": [
{
"family_name": "Li",
"given_name": "Youzhi",
"clpid": "Li-Youzhi"
},
{
"family_name": "Zhang",
"given_name": "Huiliang",
"clpid": "Zhang-Huiliang"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Wagner",
"given_name": "Kelvin H.",
"clpid": "Wagner-K-H"
},
{
"family_name": "Hemmer",
"given_name": "Philip",
"clpid": "Hemmer-P-R"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We applied a submegahertz nonlinear optical filter afforded by a cryogenically cooled spectral-hole burning crystal to ultrasound-modulated optical tomography. Our experimental results show that this technique, having the largest etendue among all available ultrasound-modulated optical tomography techniques and being immune to speckle decorrelation, offers potential for imaging in vivo and forming high resolution optical tomograms in real time. It opens an opportunity for the development of a clinically applicable high resolution optical imaging modality.",
"doi": "10.1063/1.2952489",
"pmcid": "PMC2600861",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2008-07-07",
"series_number": "1",
"volume": "93",
"issue": "1",
"pages": "Art. No. 011111"
},
{
"id": "authors:ddf6w-dxc76",
"collection": "authors",
"collection_id": "ddf6w-dxc76",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160923-135417190",
"type": "article",
"title": "In vivo burn imaging using Mueller optical coherence tomography",
"author": [
{
"family_name": "Todorovic",
"given_name": "Milo\u0161",
"clpid": "Todorovic-M"
},
{
"family_name": "Jiao",
"given_name": "Shuliang",
"clpid": "Jiao-Shuliang"
},
{
"family_name": "Ai",
"given_name": "Jun",
"clpid": "Ai-Jun"
},
{
"family_name": "Pereda-Cubi\u00e1n",
"given_name": "David",
"clpid": "Pereda-Cubi\u00e1n-D"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We report on the use of a high-speed, fiber-based Mueller-matrix optical coherence tomography system with continuous source-polarization modulation for in vivo burn depth evaluation and healing monitoring. A homemade hand-held probe with integrated optical scanning and beam delivering optics was coupled in the sample arm. In vivo burn imaging was demonstrated on porcine skin at different stages of the wound healing process, where porcine skin was used because of its similarity to the human skin. Thermally damaged region was clearly localized in the depth-resolved phase retardation image extracted from the measured Jones matrix. The burn areas in the OCT images agreed well with the histology. By using a decomposition algorithm developed by our group, we also mapped the local birefringence of the skin. The experimental results demonstrate the system's potential for in vivo burn-depth determination.",
"doi": "10.1364/OE.16.010279",
"pmcid": "PMC6986309",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "2008-07-07",
"series_number": "14",
"volume": "16",
"issue": "14",
"pages": "10279-10284"
},
{
"id": "authors:8cb5r-kvy21",
"collection": "authors",
"collection_id": "8cb5r-kvy21",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160923-155046420",
"type": "article",
"title": "Monkey brain cortex imaging by photoacoustic tomography",
"author": [
{
"family_name": "Yang",
"given_name": "Xinmai",
"clpid": "Yang-Xinmai"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) is applied to image the brain cortex of a monkey through the intact scalp and skull ex vivo. The reconstructed PAT image shows the major blood vessels on the monkey brain cortex. For comparison, the brain cortex is imaged without the scalp, and then imaged again without the scalp and skull. Ultrasound attenuation through the skull is also measured at various incidence angles. This study demonstrates that PAT of the brain cortex is capable of surviving the ultrasound signal attenuation and distortion caused by a relatively thick skull.",
"doi": "10.1117/1.2967907",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2008-07",
"series_number": "4",
"volume": "13",
"issue": "4",
"pages": "Art. No. 044009"
},
{
"id": "authors:nhdv0-px403",
"collection": "authors",
"collection_id": "nhdv0-px403",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160922-142330642",
"type": "article",
"title": "Effects of acoustic heterogeneities on transcranial brain imaging with microwave-induced thermoacoustic tomography",
"author": [
{
"family_name": "Jin",
"given_name": "Xing",
"clpid": "Jin-Xing"
},
{
"family_name": "Li",
"given_name": "Changhui",
"clpid": "Li-Changhui"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The effects of acoustic heterogeneities on transcranial brainimaging with microwave-induced thermoacoustic tomography were studied. A numerical model for calculating the propagation of thermoacousticwaves through the skull was developed and experimentally examined. The model takes into account wave reflection and refraction at the skull surfaces and therefore provides improved accuracy for the reconstruction. To evaluate when the skull-induced effects could be ignored in reconstruction, the reconstructed images obtained by the proposed method were further compared with those obtained with the method based on homogeneous acoustic properties. From simulation and experimental results, it was found that when the target region is close to the center of the brain, the effects caused by the skull layer are minimal and both reconstruction methods work well. As the target region becomes closer to the interface between the skull and braintissue, however, the skull-induced distortion becomes increasingly severe, and the reconstructed image would be strongly distorted without correcting those effects. In this case, the proposed numerical method can improve image quality by taking into consideration the wave refraction and mode conversion at the skull surfaces. This work is important for obtaining good brainimages when the thickness of the skull cannot be ignored.",
"doi": "10.1118/1.2938731",
"pmcid": "PMC2664839",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2008-07",
"series_number": "7",
"volume": "35",
"issue": "7",
"pages": "3205-3214"
},
{
"id": "authors:rpw0z-8pe14",
"collection": "authors",
"collection_id": "rpw0z-8pe14",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-102157114",
"type": "article",
"title": "Photoacoustic Tomography and Microscopy",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "By converting light waves into sound, researchers have developed a high-resolution biological imaging technique that allows them to see living tissue at new depths.",
"issn": "1047-6938",
"publisher": "Optical Society of America",
"publication": "Optics and Photonics News",
"publication_date": "2008-07",
"series_number": "7",
"volume": "19",
"issue": "7",
"pages": "37-41"
},
{
"id": "authors:9817s-tvc07",
"collection": "authors",
"collection_id": "9817s-tvc07",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160922-135211398",
"type": "article",
"title": "Design and evaluation of a novel breast cancer detection system combining both thermoacoustic (TA) and photoacoustic (PA) tomography",
"author": [
{
"family_name": "Pramanik",
"given_name": "Manojit",
"clpid": "Pramanik-M"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Li",
"given_name": "Changhui",
"clpid": "Li-Changhui"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have developed a novel scanner for breast cancer detection, integrating both thermoacoustic and photoacoustic techniques to achieve dual contrast(microwave and light absorption) imaging. This scanner is nonionizing, low cost, and can potentially provide high-resolution, dual modality three-dimensional images of the breast. The scanner uses front instead of side breast compression and dry instead of gel ultrasonic coupling. Here we present the design of the breast scanner along with initial tissue phantom study results as a precursor to an actual patient study.",
"doi": "10.1118/1.2911157",
"pmcid": "PMC2673632",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2008-06",
"series_number": "6",
"volume": "35",
"issue": "6",
"pages": "2218-2223"
},
{
"id": "authors:j2s96-mya88",
"collection": "authors",
"collection_id": "j2s96-mya88",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160926-091453637",
"type": "article",
"title": "Realtime photoacoustic microscopy in vivo with a 30-MHz ultrasound array transducer",
"author": [
{
"family_name": "Zemp",
"given_name": "Roger J.",
"clpid": "Zemp-R-J"
},
{
"family_name": "Song",
"given_name": "Liang",
"clpid": "Song-Liang"
},
{
"family_name": "Bitton",
"given_name": "Rachel",
"clpid": "Bitton-R"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present a novel high-frequency photoacoustic microscopy system capable of imaging the microvasculature of living subjects in realtime to depths of a few mm. The system consists of a high-repetition-rate Q-switched pump laser, a tunable dye laser, a 30-MHz linear ultrasound array transducer, a multichannel high-frequency data acquisition system, and a shared-RAM multi-core-processor computer. Data acquisition, beamforming, scan conversion, and display are implemented in realtime at 50 frames per second. Clearly resolvable images of 6-\u00b5m-diameter carbon fibers are experimentally demonstrated at 80 \u00b5m separation distances. Realtime imaging performance is demonstrated on phantoms and in vivo with absorbing structures identified to depths of 2.5\u20133 mm. This work represents the first high-frequency realtime photoacoustic imaging system to our knowledge.",
"doi": "10.1364/OE.16.007915",
"pmcid": "PMC2717902",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "2008-05-26",
"series_number": "11",
"volume": "16",
"issue": "11",
"pages": "7915-7928"
},
{
"id": "authors:je97v-rzj79",
"collection": "authors",
"collection_id": "je97v-rzj79",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160926-085725359",
"type": "article",
"title": "Optical-resolution photoacoustic microscopy for in vivo imaging of single capillaries",
"author": [
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Zhang",
"given_name": "Hao F.",
"clpid": "Zhang-Hao-F"
},
{
"family_name": "Hu",
"given_name": "Song",
"clpid": "Hu-Song"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Capillaries, the smallest blood vessels, are the distal end of the vasculature where oxygen and nutrients are exchanged between blood and tissue. Hence, noninvasive imaging of capillaries and function in vivo has long been desired as a window to studying fundamental physiology, such as neurovascular coupling. Existing imaging modalities cannot provide the required sensitivity and spatial resolution. We present in vivo imaging of the microvasculature including single capillaries in mice using optical-resolution photoacoustic microscopy (OR-PAM) developed in our laboratory. OR-PAM provides a lateral resolution of 5\u2009\u00b5m and an imaging depth >0.7\u2009mm.",
"doi": "10.1364/OL.33.000929",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2008-05-01",
"series_number": "9",
"volume": "33",
"issue": "9",
"pages": "929-931"
},
{
"id": "authors:3yyrr-bex05",
"collection": "authors",
"collection_id": "3yyrr-bex05",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160708-093353941",
"type": "article",
"title": "Photoacoustic imaging of biological tissue with intensity-modulated continuous-wave laser",
"author": [
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We build a photoacoustic imaging system using an\nintensity-modulated continuous-wave laser source, which is an inexpensive,\ncompact, and durable 120-mW laser diode. The goal is to\nsignificantly reduce the costs and sizes of photoacoustic imaging systems.\nBy using a bowl-shaped piezoelectric transducer, whose numerical\naperture is 0.85 and resonance frequency is 2.45 MHz, we\nimage biological tissues with a lateral resolution of 0.45 mm, an axial\nresolution of 1 mm, and an SNR as high as 43 dB.",
"doi": "10.1117/1.2904965",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2008-04-14",
"series_number": "2",
"volume": "13",
"issue": "2",
"pages": "Art. No. 024006"
},
{
"id": "authors:wkvq0-xt231",
"collection": "authors",
"collection_id": "wkvq0-xt231",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160923-134112679",
"type": "article",
"title": "Image distortion in thermoacoustic tomography caused by microwave diffraction",
"author": [
{
"family_name": "Li",
"given_name": "Changhui",
"clpid": "Li-Changhui"
},
{
"family_name": "Pramanik",
"given_name": "Manojit",
"clpid": "Pramanik-M"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We report an intrinsic image distortion in microwave-induced thermoacoustic tomography. The distortion, due to microwave diffraction in the object to be imaged, leads to nonuniform excitation of acoustic pressure during microwave illumination. Both numerical simulations and phantom experiments demonstrate this phenomenon. A method of partial correction is also provided.",
"doi": "10.1103/PhysRevE.77.031923",
"issn": "1539-3755",
"publisher": "American Physical Society",
"publication": "Physical Review E",
"publication_date": "2008-03",
"series_number": "3",
"volume": "77",
"issue": "3",
"pages": "Art. No. 031923"
},
{
"id": "authors:vb093-mrx89",
"collection": "authors",
"collection_id": "vb093-mrx89",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160927-134951939",
"type": "article",
"title": "Sentinel lymph node detection ex vivo using ultrasound-modulated optical tomography",
"author": [
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Song",
"given_name": "Kwang Hyun",
"clpid": "Song-Kwang-Hyun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We apply ultrasound-modulated optical tomography (UOT) to image ex-vivo methylene-blue-dyed sentinel lymph nodes embedded in 3.2-cm-thick chicken breast tissues. The UOT system is implemented for the first time using ring-shaped light illumination, intense acoustic bursts, and charge-coupled device (CCD) camera-based speckle contrast detection. Since the system is noninvasive, nonionizing, portable, relatively cost effective, and easy to combine with photoacoustic imaging and single element ultrasonic pulse-echo imaging, UOT can potentially be a good imaging modality for the detection of sentinel lymph nodes in breast cancer staging in vivo.",
"doi": "10.1117/1.2907791",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2008-03",
"series_number": "2",
"volume": "13",
"issue": "2",
"pages": "Art. No. 020507"
},
{
"id": "authors:958p6-rnk26",
"collection": "authors",
"collection_id": "958p6-rnk26",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160927-140749582",
"type": "article",
"title": "Simultaneous Molecular and Hypoxia Imaging of Brain Tumors In Vivo Using Spectroscopic Photoacoustic Tomography",
"author": [
{
"family_name": "Li",
"given_name": "Meng-Lin",
"clpid": "Li-Meng-Lin"
},
{
"family_name": "Oh",
"given_name": "Jung-Taek",
"clpid": "Oh-Jung-Taek"
},
{
"family_name": "Xie",
"given_name": "Xueyi",
"clpid": "Xie-Xueyi"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Wei",
"orcid": "0000-0002-5257-7675",
"clpid": "Wang-Wei"
},
{
"family_name": "Li",
"given_name": "Chun",
"clpid": "Li-Chun"
},
{
"family_name": "Lungu",
"given_name": "Gina",
"clpid": "Lungu-Gina"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Noninvasive molecular and functional imaging in vivo is promising for detecting and monitoring various physiological conditions in animals and ultimately humans. To this end, we present a novel noninvasive technology, spectroscopic photoacoustic tomography (SPAT), which offers both strong optical absorption contrast and high ultrasonic spatial resolution. Optical contrast allows spectroscopic separation of signal contributions from multiple optical absorbers (e.g., oxyhemoglobin, deoxyhemoglobin, and a molecular contrast agent), thus enabling simultaneous molecular and functional imaging. SPAT successfully imaged with high resolution the distribution of a molecular contrast agent targeting integrin overexpressed in human U87 glioblastomas in nude mouse brains. Simultaneously, SPAT also imaged the hemoglobin oxygen saturation and the total hemoglobin concentration of the vasculature, which revealed hypoxia in tumor neovasculature. Therefore, SPAT can potentially lead to better understanding of the interrelationships between hemodynamics and specific biomarkers associated with tumor progression.",
"doi": "10.1109/JPROC.2007.913515",
"issn": "0018-9219",
"publisher": "IEEE",
"publication": "Proceedings of the IEEE",
"publication_date": "2008-03",
"series_number": "3",
"volume": "96",
"issue": "3",
"pages": "481-489"
},
{
"id": "authors:b32qp-47k58",
"collection": "authors",
"collection_id": "b32qp-47k58",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160922-074407860",
"type": "article",
"title": "Curved array photoacoustic tomographic system for small animal imaging",
"author": [
{
"family_name": "Gamelin",
"given_name": "John",
"clpid": "Gamelin-J"
},
{
"family_name": "Aguirre",
"given_name": "Andres",
"clpid": "Aguirre-A"
},
{
"family_name": "Maurudis",
"given_name": "Anastasios",
"clpid": "Maurudis-A"
},
{
"family_name": "Huang",
"given_name": "Fei",
"clpid": "Huang-Fei"
},
{
"family_name": "Castillo",
"given_name": "Diego",
"clpid": "Castillo-D"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Zhu",
"given_name": "Quing",
"clpid": "Zhu-Quing"
}
],
"abstract": "We present systematic characterization of a photoacoustic imaging system optimized for rapid, high-resolution tomographic imaging of small animals. The system is based on a 128-element ultrasonic transducer array with a 5-MHz center frequency and 80% bandwidth shaped to a quarter circle of 25mm radius. A 16-channel data-acquisition module and dedicated channel detection electronics enable capture of a 90-deg field-of-view image in less than 1s and a complete 360-deg scan using sample rotation within 15s. Measurements on cylindrical phantom targets demonstrate a resolution of better than 200\u03bcm and high-sensitivity detection of 580-\u03bcm blood tubing to depths greater than 3cm in a turbid medium with reduced scattering coefficient \u03bc\u2032s =7.8cm^(\u22121). The system is used to systematically investigate the effects of target size, orientation, and geometry on tomographic imaging. As a demonstration of these effects and the system imaging capabilities, we present tomographic photoacoustic images of the brain vasculature of an ex vivo mouse with varying measurement aperture. For the first time, according to our knowledge, resolution of sub-200-\u03bcm vessels with an overlying turbid medium of greater than 2cm depth is demonstrated using only intrinsic biological contrast.",
"doi": "10.1117/1.2907157",
"pmcid": "PMC2507725",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2008-03",
"series_number": "2",
"volume": "13",
"issue": "2",
"pages": "Art. No. 024007"
},
{
"id": "authors:xe25a-06k80",
"collection": "authors",
"collection_id": "xe25a-06k80",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160927-141815359",
"type": "article",
"title": "Tutorial on Photoacoustic Microscopy and Computed Tomography",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The field of photoacoustic tomography has experienced considerable growth in the past few years. Although several commercially available pure optical imaging modalities, including confocal microscopy, two-photon microscopy, and optical coherence tomography, have been highly successful, none of these technologies can provide penetration beyond ~1 mm into scattering biological tissues, because they are based on ballistic and quasi-ballistic photons. Heretofore, there has been a void in high-resolution optical imaging beyond this penetration limit. Photoacoustic tomography, which combines high ultrasonic resolution and strong optical contrast in a single modality, has broken through this limitation and filled this void. In this paper, the fundamentals of photoacoustics are first introduced. Then, scanning photoacoustic microscopy and reconstruction-based photoacoustic tomography (or photoacoustic computed tomography) are covered.",
"doi": "10.1109/JSTQE.2007.913398",
"issn": "1077-260X",
"publisher": "IEEE",
"publication": "IEEE Journal of Selected Topics in Quantum Electronics",
"publication_date": "2008-01",
"series_number": "1",
"volume": "14",
"issue": "1",
"pages": "171-179"
},
{
"id": "authors:vaefz-gy477",
"collection": "authors",
"collection_id": "vaefz-gy477",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160708-154020939",
"type": "article",
"title": "Photoacoustic Doppler flow measurement in optically scattering media",
"author": [
{
"family_name": "Fang",
"given_name": "Hui",
"clpid": "Fang-Hui"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We recently observed the photoacoustic Doppler effect from flowing small light-absorbing particles. Here, we apply the effect to measure blood-mimicking fluid flow in an optically scattering medium. The light scattering in the medium decreases the amplitude of the photoacoustic Doppler signal but does not affect either the magnitude or the directional discrimination of the photoacoustic Doppler shift. This technology may hold promise for a new Doppler method for measuring blood flow in microcirculation with high sensitivity.",
"doi": "10.1063/1.2825569",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2007-12-24",
"series_number": "26",
"volume": "91",
"issue": "26",
"pages": "Art. No. 264103"
},
{
"id": "authors:tfjtx-2xx04",
"collection": "authors",
"collection_id": "tfjtx-2xx04",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161005-110258933",
"type": "article",
"title": "Photoacoustic Tomography of a Rat Cerebral Cortex in vivo with Au Nanocages as an Optical Contrast Agent",
"author": [
{
"family_name": "Yang",
"given_name": "Xinmai",
"clpid": "Yang-Xinmai"
},
{
"family_name": "Skrabalak",
"given_name": "Sara E.",
"clpid": "Skrabalak-S-E"
},
{
"family_name": "Li",
"given_name": "Zhi-Yuan",
"clpid": "Li-Zhi-Yuan"
},
{
"family_name": "Xia",
"given_name": "Younan",
"clpid": "Xia-Younan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Poly(ethylene glycol)-coated Au nanocages have been evaluated as a potential near-infrared (NIR) contrast agent for photoacoustic tomography (PAT). Previously, Au nanoshells were found to be an effective NIR contrast agent for PAT; however, Au nanocages with their more compact sizes (<50 nm compared to >100 nm for Au nanoshells) and larger optical absorption cross sections should be better suited for in vivo applications. We sequentially injected Au nanocages into the circulatory system of a rat in three administrations and in vivo PAT was conducted immediately prior to the first injection and continued until 5 h after the final injection. A gradual enhancement of the optical absorption in the cerebral cortex, by up to 81%, was observed over the course of the experiment.",
"doi": "10.1021/nl072349r",
"issn": "1530-6984",
"publisher": "American Chemical Society",
"publication": "Nano Letters",
"publication_date": "2007-12",
"series_number": "12",
"volume": "7",
"issue": "12",
"pages": "3798-3802"
},
{
"id": "authors:8bqnm-6z239",
"collection": "authors",
"collection_id": "8bqnm-6z239",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160927-155005101",
"type": "article",
"title": "Deep reflection-mode photoacoustic imaging of biological tissue",
"author": [
{
"family_name": "Song",
"given_name": "Kwang Hyun",
"clpid": "Song-Kwang-Hyun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A reflection-mode photoacoustic (PA) imaging system was designed and built to image deep structures in biological tissues. We chose near-infrared laser pulses of 804-nm wavelength for PA excitation to achieve deep penetration. To minimize unwanted surface signals, we adopted dark-field ring-shaped illumination. This imaging system employing a 5-MHz spherically focused ultrasonic transducer provides penetration up to 38mm in chicken breast tissue. At the 19-mm depth, the axial resolution is 144\u03bcm and the transverse resolution is 560\u03bcm. Internal organs of small animals were imaged clearly.",
"doi": "10.1117/1.2818045",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2007-12",
"series_number": "6",
"volume": "12",
"issue": "6",
"pages": "Art. No. 060503"
},
{
"id": "authors:qf1wc-czw47",
"collection": "authors",
"collection_id": "qf1wc-czw47",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161005-074721592",
"type": "article",
"title": "Effects of wavelength-dependent fluence attenuation on the noninvasive photoacoustic imaging of hemoglobin oxygen saturation in subcutaneous vasculature in vivo",
"author": [
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Zhang",
"given_name": "Hao F.",
"clpid": "Zhang-Hao-F"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Quantitative measurements of the oxygen saturation of hemoglobin (sO_2) in a blood vessel in vivo presents a challenge in photoacoustic imaging. As a result of wavelength-dependent optical attenuation in the skin, the local fluence at a subcutaneous vessel varies with the optical wavelength in spectral measurement and hence needs to be compensated for so that the intrinsic absorption coefficient can be recovered. Here, by employing a simplified double-layer skin model, we demonstrate that although the absolute value of sO_2 in a vessel is seriously affected by the volume fraction of blood and the spatially averaged sO_2 in the dermis, the difference of sO_2 between neighboring vessels is minimally affected. Experimentally, we acquire compensational factors for the wavelength-dependent optical attenuation by measuring the PA spectrum of a subcutaneously inserted 25 \u00b5m thick black film using our PA microscope. We demonstrate in vivo that the difference in sO_2 between a typical artery and a typical vein is conserved before and after spectral compensation. This conservation holds regardless of the animal's systemic physiological state.",
"doi": "10.1088/0266-5611/23/6/S09",
"issn": "0266-5611",
"publisher": "IOP",
"publication": "Inverse Problems",
"publication_date": "2007-12",
"series_number": "6",
"volume": "23",
"issue": "6",
"pages": "S113-S122"
},
{
"id": "authors:5zpa3-n7c85",
"collection": "authors",
"collection_id": "5zpa3-n7c85",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160616-111336419",
"type": "article",
"title": "Photoacoustic Doppler Effect from Flowing Small Light-Absorbing Particles",
"author": [
{
"family_name": "Fang",
"given_name": "Hui",
"clpid": "Fang-Hui"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "From the flow of a suspension of micrometer-scale carbon particles, the photoacoustic Doppler shift is observed. As predicted theoretically, the observed Doppler shift equals half of that in Doppler ultrasound and does not depend on the direction of laser illumination. This new physical phenomenon provides a basis for developing photoacoustic Doppler flowmetry, which can potentially be used for detecting fluid flow in optically scattering media and especially low-speed blood flow of relatively deep microcirculation in biological tissue.",
"doi": "10.1103/PhysRevLett.99.184501",
"issn": "0031-9007",
"publisher": "American Physical Society",
"publication": "Physical Review Letters",
"publication_date": "2007-11-02",
"series_number": "18",
"volume": "99",
"issue": "18",
"pages": "Art. No. 184501"
},
{
"id": "authors:r9v3n-dj123",
"collection": "authors",
"collection_id": "r9v3n-dj123",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161005-080655639",
"type": "article",
"title": "Evaluation of the magneto-optical effect in biological tissue models using optical coherence tomography",
"author": [
{
"family_name": "Pereda-Cubi\u00e1n",
"given_name": "David",
"clpid": "Pereda-Cubi\u00e1n-D"
},
{
"family_name": "Todorovi\u0107",
"given_name": "Milo\u0161",
"clpid": "Todorovi\u0107-M"
},
{
"family_name": "Arce-Diego",
"given_name": "Jos\u00e9 Luis",
"clpid": "Arce-Diego-J-L"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "For the first time to our knowledge, an experimental evaluation of the Faraday effect\u2013induced polarization rotation in a biological tissue phantom is reported. The rotation of the polarization plane produced in the optical beam propagating through an Intralipid solution was evaluated using polarization-sensitive optical coherence tomography (PS-OCT), and the experimental results closely matched the theoretical values. The angle of rotation is proportional to the traversed path length along the magnetic field and can potentially be used to estimate the actual penetration depth.",
"doi": "10.1117/1.2818103",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2007-11",
"series_number": "6",
"volume": "12",
"issue": "6",
"pages": "Art. No. 060502"
},
{
"id": "authors:6y6t0-q1b23",
"collection": "authors",
"collection_id": "6y6t0-q1b23",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161005-113655013",
"type": "article",
"title": "Photoacoustic tomography of a rat cerebral cortex with a ring-based ultrasonic virtual point detector",
"author": [
{
"family_name": "Yang",
"given_name": "Xinmai",
"clpid": "Yang-Xinmai"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We image a rat cerebral cortex in situ by using a ring-based ultrasonic virtual point detector developed previously. Compared to the image generated by a finite-aperture detector, the image generated by the virtual point detector has a uniformly distributed resolution throughout the imaged area, owing to the lack of aperture effect of the ultrasonic detector. At the periphery of the image, the signal-to-noise ratio of the image obtained by the virtual point detector is also better than that of a finite-aperture detector. Furthermore, the virtual point detector can be scanned inside the brain to improve the local signal-to-noise ratio.",
"doi": "10.1117/1.2823076",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2007-11",
"series_number": "6",
"volume": "12",
"issue": "6",
"pages": "Art. No. 060507"
},
{
"id": "authors:gfkr7-54n78",
"collection": "authors",
"collection_id": "gfkr7-54n78",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161005-102709966",
"type": "article",
"title": "Optical coherence computed tomography",
"author": [
{
"family_name": "Li",
"given_name": "Li",
"clpid": "Li-Li"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A time-resolved optical tomography, optical coherence computed tomography, is proposed to bridge the gap between diffuse optical tomography and optical coherence tomography. Both ballistic and multiple-scattered photons are measured at multiple source-detection positions by low-coherence interferometry providing a temporal resolution smaller than 100fs. A light-tissue interaction model was established using the time-resolved Monte Carlo method. The optical properties were then reconstructed by solving the inverse transient radiative transport problem under the first Born approximation. Absorbing inclusions of 100\u03bcm diameter were imaged through a 2.6-mm-thick (\u223c30 scattering mean-free-paths) scattering medium.",
"doi": "10.1063/1.2793625",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2007-10-01",
"series_number": "14",
"volume": "91",
"issue": "14",
"pages": "Art. No. 141107"
},
{
"id": "authors:ahkry-fhf14",
"collection": "authors",
"collection_id": "ahkry-fhf14",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160927-154154443",
"type": "article",
"title": "Correlation transfer equation for multiply scattered light modulated by an ultrasonic pulse",
"author": [
{
"family_name": "Sakad\u017ei\u0107",
"given_name": "Sava",
"clpid": "Sakad\u017ei\u0107-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We develop a temporal correlation transfer equation (CTE) and a Monte Carlo algorithm (MC) for multiply scattered light modulated by an ultrasonic pulse propagating in an optically scattering medium, where the ultrasound field can be nonuniform and the medium can have spatially heterogeneous distribution of optical parameters. The CTE and MC can be used to obtain the time-varying specific intensity and the spatial distribution of the time-dependent power spectral density, respectively, of ultrasound-modulated light. We expect the CTE and MC to be applicable for estimation of contrast and resolution in a wide spectrum of conditions in ultrasound-modulated optical tomography of soft biological tissues.",
"doi": "10.1364/JOSAA.24.002797",
"issn": "1084-7529",
"publisher": "Optical Society of America",
"publication": "Journal of the Optical Society of America A",
"publication_date": "2007-09",
"series_number": "9",
"volume": "24",
"issue": "9",
"pages": "2797-2806"
},
{
"id": "authors:gymb7-9hx17",
"collection": "authors",
"collection_id": "gymb7-9hx17",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161005-081635259",
"type": "article",
"title": "Imaging optically scattering objects with ultrasound-modulated optical tomography",
"author": [
{
"family_name": "Kothapalli",
"given_name": "Sri-Rajasekhar",
"clpid": "Kothapalli-S-R"
},
{
"family_name": "Sakad\u017ei\u0107",
"given_name": "Sava",
"clpid": "Sakad\u017ei\u0107-S"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We show the feasibility of imaging objects having different optical scattering coefficients relative to the surrounding scattering medium using ultrasound-modulated optical tomography (UOT). While the spatial resolution depends on ultrasound parameters, the image contrast depends on the difference in scattering coefficient between the object and the surrounding medium. Experimental measurements obtained with a CCD-based speckle contrast detection scheme are in agreement with Monte Carlo simulations and analytical calculations. This study complements previous UOT experiments that demonstrated optical absorption contrast.",
"doi": "10.1364/OL.32.002351",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2007-08-15",
"series_number": "16",
"volume": "32",
"issue": "16",
"pages": "2351-2353"
},
{
"id": "authors:cf39j-4tp22",
"collection": "authors",
"collection_id": "cf39j-4tp22",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161005-093141303",
"type": "article",
"title": "Multi-optical-wavelength ultrasound-modulated optical tomography: a phantom study",
"author": [
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We used multiple optical wavelengths to study ultrasound-modulated optical tomography (UOT) in tissue phantoms. By using intense acoustic bursts and a CCD camera-based speckle contrast detection technique, we observed variations of the ultrasound-modulated signal at various optical absorptions. The experimental variations were found to be highly correlated with predictions from Monte Carlo simulations. By irradiating the sample at two optical wavelengths, we quantitatively estimated the total concentration and the concentration ratio of double dyes in objects embedded in tissue phantoms. The results suggest that UOT can potentially provide noninvasive functional imaging of the total concentration and oxygen saturation of hemoglobin in biological tissue.",
"doi": "10.1364/OL.32.002285",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2007-08-15",
"series_number": "16",
"volume": "32",
"issue": "16",
"pages": "2285-2287"
},
{
"id": "authors:bc3fd-xtt17",
"collection": "authors",
"collection_id": "bc3fd-xtt17",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161005-100353189",
"type": "article",
"title": "Multiple-source optical diffusion approximation for a multilayer scattering medium",
"author": [
{
"family_name": "Hollmann",
"given_name": "Joseph L.",
"clpid": "Hollmann-J-L"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A method for improving the accuracy of the optical diffusion theory for a multilayer scattering medium is presented. An infinitesimally narrow incident light beam is replaced by multiple isotropic point sources of different strengths that are placed in the scattering medium along the incident beam. The multiple sources are then used to develop a multilayer diffusion theory. Diffuse reflectance is then computed using the multilayer diffusion theory and compared with accurate data computed by the Monte Carlo method. This multisource method is found to be significantly more accurate than the previous single-source method.",
"doi": "10.1364/AO.46.006004",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2007-08-10",
"series_number": "23",
"volume": "46",
"issue": "23",
"pages": "6004-6009"
},
{
"id": "authors:snn5k-mbr97",
"collection": "authors",
"collection_id": "snn5k-mbr97",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161102-153231273",
"type": "article",
"title": "Ring-based ultrasonic virtual point detector with applications to photoacoustic tomography",
"author": [
{
"family_name": "Yang",
"given_name": "Xinmai",
"clpid": "Yang-Xinmai"
},
{
"family_name": "Li",
"given_name": "Meng-Lin",
"clpid": "Li-Meng-Lin"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "An ultrasonic virtual point detector is constructed using the center of a ring transducer. The virtual point detector provides ideal omnidirectional detection free of any aperture effect. Compared with a real point detector, the virtual one has lower thermal noise and can be scanned with its center inside a physically inaccessible medium. When applied to photoacoustictomography, the virtual point detector provides both high spatial resolution and high signal-to-noise ratio. It can also be potentially applied to other ultrasound-related technologies.",
"doi": "10.1063/1.2749856",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2007-06-18",
"series_number": "25",
"volume": "90",
"issue": "25",
"pages": "Art. No. 251103"
},
{
"id": "authors:t7q6g-bvz85",
"collection": "authors",
"collection_id": "t7q6g-bvz85",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161102-153638006",
"type": "article",
"title": "Ultrasound-modulated optical tomography with intense acoustic bursts",
"author": [
{
"family_name": "Zemp",
"given_name": "Roger J.",
"clpid": "Zemp-R-J"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Ultrasound-modulated optical tomography (UOT) detects ultrasonically modulated light to spatially localize multiply scattered photons in turbid media with the ultimate goal of imaging the optical properties in living subjects. A principal challenge of the technique is weak modulated signal strength. We discuss ways to push the limits of signal enhancement with intense acoustic bursts while conforming to optical and ultrasonic safety standards. A CCD-based speckle-contrast detection scheme is used to detect acoustically modulated light by measuring changes in speckle statistics between ultrasound-on and ultrasound-off states. The CCD image capture is synchronized with the ultrasound burst pulse sequence. Transient acoustic radiation force, a consequence of bursts, is seen to produce slight signal enhancement over pure ultrasonic-modulation mechanisms for bursts and CCD exposure times of the order of milliseconds. However, acoustic radiation-force-induced shear waves are launched away from the acoustic sample volume, which degrade UOT spatial resolution. By time gating the CCD camera to capture modulated light before radiation force has an opportunity to accumulate significant tissue displacement, we reduce the effects of shear-wave image degradation, while enabling very high signal-to-noise ratios. Additionally, we maintain high-resolution images representative of optical and not mechanical contrast. Signal-to-noise levels are sufficiently high so as to enable acquisition of 2D images of phantoms with one acoustic burst per pixel.",
"doi": "10.1364/AO.46.001615",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2007-04-01",
"series_number": "10",
"volume": "46",
"issue": "10",
"pages": "1615-1623"
},
{
"id": "authors:tkyfv-0w859",
"collection": "authors",
"collection_id": "tkyfv-0w859",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190305-153256593",
"type": "article",
"title": "Topics in Biomedical Optics: introduction",
"author": [
{
"family_name": "Faris",
"given_name": "Gregory W.",
"clpid": "Faris-G-W"
},
{
"family_name": "Ntziachristos",
"given_name": "Vasilis",
"clpid": "Ntziachristos-V"
},
{
"family_name": "Rector",
"given_name": "David M.",
"clpid": "Rector-D-M"
},
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "This Applied Optics feature issue on Topics in Biomedical Optics highlights papers presented at the 2006 Biomedical Optics Topical Meeting sponsored by the Optical Society of America. The feature includes 40 papers that represent a cross section of topics that were covered at the meeting.",
"doi": "10.1364/ao.46.001595",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2007-04-01",
"series_number": "10",
"volume": "46",
"issue": "10",
"pages": "1595-1596"
},
{
"id": "authors:c0jwy-6ws20",
"collection": "authors",
"collection_id": "c0jwy-6ws20",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-094419130",
"type": "article",
"title": "In vivo imaging of subcutaneous structures using functional photoacoustic microscopy",
"author": [
{
"family_name": "Zhang",
"given_name": "Hao F.",
"clpid": "Zhang-Hao-F"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Functional photoacoustic microscopy (fPAM) is a hybrid technology that permits noninvasive imaging of the optical absorption contrast in subcutaneous biological tissues. fPAM uses a focused ultrasonic transducer to detect high-frequency photoacoustic (PA) signals. Volumetric images of biological tissues can be formed by two-dimensional raster scanning, and functional parameters can be further extracted from spectral measurements. fPAM is safe and applicable to animals as well as humans. This protocol provides guidelines for parameter selection, system alignment, imaging operation, laser safety and data processing for in vivo fPAM. It currently takes ~100 min to carry out this protocol, including ~50 min for data acquisition using a 10-Hz pulse-repetition-rate laser system. The data acquisition time, however, can be significantly reduced by using a laser system with a higher pulse repetition rate.",
"doi": "10.1038/nprot.2007.108",
"issn": "1754-2189",
"publisher": "Nature Publishing Group",
"publication": "Nature Protocols",
"publication_date": "2007-04",
"series_number": "4",
"volume": "2",
"issue": "4",
"pages": "797-804"
},
{
"id": "authors:a45rs-bht10",
"collection": "authors",
"collection_id": "a45rs-bht10",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161102-152215028",
"type": "article",
"title": "Photorefractive detection of tissue optical and mechanical properties by ultrasound modulated optical tomography",
"author": [
{
"family_name": "Xu",
"given_name": "Xiao",
"clpid": "Xu-Xiao"
},
{
"family_name": "Zhang",
"given_name": "Huiliang",
"clpid": "Zhang-Huiliang"
},
{
"family_name": "Hemmer",
"given_name": "Philip",
"clpid": "Hemmer-P-R"
},
{
"family_name": "Qing",
"given_name": "De-kui",
"clpid": "Qing-De-kui"
},
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Ultrasound-modulated optical tomography is a developing hybrid imaging modality that combines high optical contrast and good ultrasonic resolution for imaging soft biological tissue. We developed a photorefractive-crystal-based, time-resolved detection scheme with the use of a millisecond long ultrasound burst to image both the optical and the mechanical properties of biological tissues, with improved detection efficiency of ultrasound-tagged photons.",
"doi": "10.1364/OL.32.000656",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2007-03-15",
"series_number": "6",
"volume": "32",
"issue": "6",
"pages": "656-658"
},
{
"id": "authors:mewqv-pkt65",
"collection": "authors",
"collection_id": "mewqv-pkt65",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161005-085823162",
"type": "article",
"title": "Limitations of quantitative photoacoustic measurements of blood oxygenation in small vessels",
"author": [
{
"family_name": "Sivaramakrishnan",
"given_name": "Mathangi",
"clpid": "Sivaramakrishnan-M"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Zhang",
"given_name": "Hao F.",
"clpid": "Zhang-Hao-F"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We investigate the feasibility of obtaining accurate quantitative information, such as local blood oxygenation level (sO_2), with a spatial resolution of about 50 \u00b5m from spectral photoacoustic (PA) measurements. The optical wavelength dependence of the peak values of the PA signals is utilized to obtain the local blood oxygenation level. In our in vitro experimental models, the PA signal amplitude is found to be linearly proportional to the blood optical absorption coefficient when using ultrasonic transducers with central frequencies high enough such that the ultrasonic wavelengths are shorter than the light penetration depth into the blood vessels. For an optical wavelength in the 578\u2013596 nm region, with a transducer central frequency that is above 25 MHz, the sensitivity and accuracy of sO_2 inversion is shown to be better than 4%. The effect of the transducer focal position on the accuracy of quantifying blood oxygenation is found to be negligible. In vivo oxygenation measurements of rat skin microvasculature yield results consistent with those from in vitro studies, although factors specific to in vivo measurements, such as the spectral dependence of tissue optical attenuation, dramatically affect the accuracy of sO_2 quantification in vivo.",
"doi": "10.1088/0031-9155/52/5/010",
"issn": "0031-9155",
"publisher": "IOP",
"publication": "Physics in Medicine and Biology",
"publication_date": "2007-03-07",
"series_number": "5",
"volume": "52",
"issue": "5",
"pages": "1349-1361"
},
{
"id": "authors:jx43n-j3a56",
"collection": "authors",
"collection_id": "jx43n-j3a56",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160711-142550053",
"type": "article",
"title": "Photoacoustic imaging of lacZ gene expression in vivo",
"author": [
{
"family_name": "Li",
"given_name": "Li",
"clpid": "Li-Li"
},
{
"family_name": "Zemp",
"given_name": "Roger J.",
"clpid": "Zemp-R-J"
},
{
"family_name": "Lungu",
"given_name": "Gina",
"clpid": "Lungu-Gina"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In the postgenomic era, imaging techniques are playing an important role in visualizing gene expression in vivo. This work represents the first demonstration of photoacoustic tomography (PAT) for reporter gene imaging. Rats inoculated with 9L/lacZ gliosarcoma tumor cells are imaged with PAT before and after injection of X-gal, a colorimetric assay for the lacZ-encoded enzyme \u03b2 \n\u03b2\n-galactosidase. Using far-red optical illumination, the genetically tagged tumors in rats are clearly visualized by PAT following the assay. The spatial resolution is quantified to be less than 400\u03bcm \n400\u03bcm\n, while 500-nM-level sensitivity is demonstrated. With the future development of new absorption-based reporter gene systems, it is anticipated that photoacoustic technology will provide a valuable tool for molecular imaging research.",
"doi": "10.1117/1.2717531",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2007-03",
"series_number": "2",
"volume": "12",
"issue": "2",
"pages": "Art. No. 020504"
},
{
"id": "authors:7hd0k-taq38",
"collection": "authors",
"collection_id": "7hd0k-taq38",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160927-122347693",
"type": "article",
"title": "Imaging of hemoglobin oxygen saturation variations in single vessels in vivo using photoacoustic microscopy",
"author": [
{
"family_name": "Zhang",
"given_name": "Hao F.",
"clpid": "Zhang-Hao-F"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Sivaramakrishnan",
"given_name": "Mathangi",
"clpid": "Sivaramakrishnan-M"
},
{
"family_name": "Stoica",
"given_name": "Gheorghe",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic microscopy was used to noninvasively image variations in hemoglobin oxygen saturation (SO_2) in the subcutaneous microvasculature of rats in vivo. In phantom tests, the calculated concentration fractions of red ink in double-ink mixtures matched the actual values with a 1% error. In ex vivo studies, the calculated SO_2 in bovine blood agreed with the standard spectrophotometric measurements within a 4% systematic difference. In in vivo studies, arteries and veins were separated based on the measured SO_2 values and variations in SO_2 between different physiological states (hyperoxia, normoxia, and hypoxia) were imaged in single blood vessels.",
"doi": "10.1063/1.2435697",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2007-01-29",
"series_number": "5",
"volume": "90",
"issue": "5",
"pages": "Art. No. 053901"
},
{
"id": "authors:8cgkw-3vq09",
"collection": "authors",
"collection_id": "8cgkw-3vq09",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161005-104616569",
"type": "article",
"title": "Photoacoustic imaging of the microvasculature with a high-frequency ultrasound array transducer",
"author": [
{
"family_name": "Zemp",
"given_name": "Roger J.",
"clpid": "Zemp-R-J"
},
{
"family_name": "Bitton",
"given_name": "Rachel",
"clpid": "Bitton-R"
},
{
"family_name": "Li",
"given_name": "Meng-Lin",
"clpid": "Li-Meng-Lin"
},
{
"family_name": "Shung",
"given_name": "K. Kirk",
"clpid": "Shung-K-Kirk"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Visualization of microvascular networks could provide new information about function and disease. We demonstrate the capabilities of a 30-MHz ultrasound array system for photoacoustic microscopy of small (\u2264300\u03bcm) vessels in a rat. 3D images obtained by translating the array in the elevation direction are compared with photographs of excised skin. The system is shown to have 100-\u03bcm lateral resolution, 25-\u03bcm axial resolution, and 3-mm imaging depth. To our knowledge this is the first report on photoacoustic microscopy of the microvasculature with a high-frequency array transducer. It is anticipated that the system can be used for studying and diagnosing a number of diseases including cancer, atherosclerosis, dermatological disorders, and peripheral microvascular complications in diabetes.",
"doi": "10.1117/1.2709850",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2007-01",
"series_number": "1",
"volume": "12",
"issue": "1",
"pages": "Art. No. 010501"
},
{
"id": "authors:yegx6-pe706",
"collection": "authors",
"collection_id": "yegx6-pe706",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160927-144537424",
"type": "article",
"title": "Boundary conditions in photoacoustic tomography and image reconstruction",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Yang",
"given_name": "Xinmai",
"clpid": "Yang-Xinmai"
}
],
"abstract": "Recently, the field of photoacoustic tomography has experienced considerable growth. Although several commercially available pure optical imaging modalities, including confocal microscopy, two-photon microscopy, and optical coherence tomography, have been highly successful, none of these technologies can penetrate beyond \u223c1mm into scattering biological tissues because all of them are based on ballistic and quasiballistic photons. Consequently, heretofore there has been a void in high-resolution optical imaging beyond this depth limit. Photoacoustic tomography has filled this void by combining high ultrasonic resolution and strong optical contrast in a single modality. However, it has been assumed in reconstruction of photoacoustic tomography until now that ultrasound propagates in a boundary-free infinite medium. We present the boundary conditions that must be considered in certain imaging configurations; the associated inverse solutions for image reconstruction are provided and validated by numerical simulation and experiment. Partial planar, cylindrical, and spherical detection configurations with a planar boundary are covered, where the boundary can be either hard or soft. Analogously to the method of images of sources, which is commonly used in forward problems, the ultrasonic detectors are imaged about the boundary to satisfy the boundary condition in the inverse problem.",
"doi": "10.1117/1.2709861",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2007-01",
"series_number": "1",
"volume": "12",
"issue": "1",
"pages": "Art. No. 014027"
},
{
"id": "authors:xhr4e-1fj96",
"collection": "authors",
"collection_id": "xhr4e-1fj96",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161005-083813036",
"type": "article",
"title": "In vivo imaging and characterization of hypoxia-induced neovascularization and tumor invasion",
"author": [
{
"family_name": "Lungu",
"given_name": "Gina F.",
"clpid": "Lungu-Gina-F"
},
{
"family_name": "Li",
"given_name": "Meng-Lin",
"clpid": "Li-Meng-Lin"
},
{
"family_name": "Xie",
"given_name": "Xueyi",
"clpid": "Xie-Xueyi"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
}
],
"abstract": "Hypoxia is a critical event in tumor progression and angiogenesis. Hypoxia can be detected noninvasively by a novel spectroscopic photoacoustic tomography technology (SPAT) and this finding is supported by our molecular biology investigation aimed to elucidate the etiopathogenesis of SPAT detected hypoxia and angiogenesis. The present study provides an integrated approach to define oxygen status (hypoxia) of intracranial tumor xenografts using spectroscopic photoacoustic tomography. Brain tumors can be identified based on their distorted vascular architecture and oxygen saturation (SO2) images. Noninvasive in vivo tumor oxygenation imaging using SPAT is based on the spectroscopic absorption differences between oxyhemoglobin (O2Hb) and deoxyhemoblobin (HHb). Sprague-Dawley rats inoculated intracranially with ENU1564, a carcinogen-induced rat mammary adenocarcinoma cell line, were imaged with SPAT three weeks post inoculation. Proteins important for tumor angiogenesis and invasion were detected in hypoxic brain foci identified by SPAT and were elevated compared with control brain. Immunohistochemistry, Western blotting, and semi-quantitative RT-PCR showed that HIF-1 \u03b1, VEGF-A, and VEGFR2 (Flk-1) protein and mRNA expression levels were significantly higher (P<0.05) in brain tumor tissues compared to normal brain. Gelatin zymography and RT-PCR demonstrated the upregulation of MMP-9 in tumor foci compared with brain control. Together these results suggest the critical role of hypoxia in driving tumor angiogenesis and invasion through upregulation of target genes important for these functions. Moreover this report validates our hypothesis that a novel noninvasive technology (SPAT) developed in our laboratory is suitable for detection of tumors, hypoxia, and angiogenesis.",
"doi": "10.3892/ijo.30.1.45",
"issn": "1019-6439",
"publisher": "Spandidos Publications",
"publication": "International Journal of Oncology",
"publication_date": "2007-01",
"series_number": "1",
"volume": "30",
"issue": "1",
"pages": "45-54"
},
{
"id": "authors:ptcxk-ztn72",
"collection": "authors",
"collection_id": "ptcxk-ztn72",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-124050746",
"type": "article",
"title": "Thermoacoustic tomography with correction for acoustic speed variations",
"author": [
{
"family_name": "Jin",
"given_name": "Xing",
"clpid": "Jin-Xing"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Thermoacoustic tomography (TAT) is a technique that measures microwave-induced thermoacoustic waves at the boundary of biological tissue and generates images of internal microwave absorption distributions from the measurements. Existing reconstruction algorithms for TAT are based on the assumption that the acoustic properties in the tissue are homogeneous. Biological tissue, however, has heterogeneous acoustic properties, which lead to distortion and blurring of small buried objects in the reconstructed images. In this paper we develop a correction method based on ultrasonic transmission tomography (UTT) to improve the image quality of TAT. Numerical simulations and phantom experiments verify the effectiveness of this correction method.",
"doi": "10.1088/0031-9155/51/24/010",
"issn": "0031-9155",
"publisher": "IOP",
"publication": "Physics in Medicine and Biology",
"publication_date": "2006-12-21",
"series_number": "24",
"volume": "51",
"issue": "24",
"pages": "6437-6448"
},
{
"id": "authors:aaz65-4a118",
"collection": "authors",
"collection_id": "aaz65-4a118",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-102659762",
"type": "article",
"title": "In vivo volumetric imaging of subcutaneous microvasculature by photoacoustic microscopy",
"author": [
{
"family_name": "Zhang",
"given_name": "Hao F.",
"clpid": "Zhang-Hao-F"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Li",
"given_name": "Meng-Lin",
"clpid": "Li-Meng-Lin"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic microscopy was developed to achieve volumetric imaging of the anatomy and functions of the subcutaneous microvasculature in both small animals and humans in vivo with high spatial resolution and high signal-to-background ratio. By following the skin contour in raster scanning, the ultrasonic transducer maintains focusing in the region of interest. Furthermore, off-focus lateral resolution is improved by using a synthetic-aperture focusing technique based on the virtual point detector concept. Structural images are acquired in both rats and humans, whereas functional images representing hemoglobin oxygen saturation are acquired in rats. After multiscale vesselness filtering, arterioles and venules in the image are separated based on the imaged oxygen saturation levels. Detailed structural information, such as vessel depth and spatial orientation, are revealed by volume rendering.",
"doi": "10.1364/OE.14.009317",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "2006-10-02",
"series_number": "20",
"volume": "14",
"issue": "20",
"pages": "9317-9323"
},
{
"id": "authors:5e57e-p7k94",
"collection": "authors",
"collection_id": "5e57e-p7k94",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161109-152329007",
"type": "article",
"title": "Imaging acute thermal burns by photoacoustic microscopy",
"author": [
{
"family_name": "Zhang",
"given_name": "Hao F.",
"clpid": "Zhang-Hao-F"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The clinical significance of a burn depends on the percentage of total body involved and the depth of the burn. Hence a noninvasive method that is able to evaluate burn depth would be of great help in clinical evaluation. To this end, photoacoustic microscopy is used to determine the depth of acute thermal burns by imaging the total hemoglobin concentration in the blood that accumulates along the boundaries of injuries as a result of thermal damage to the vasculature. We induce acute thermal burns in vivo on pig skin with cautery. Photoacoustic images of the burns are acquired after skin excision. In a burn treated at 175\u00b0C for 20s, the maximum imaged burn depth is 1.73\u00b10.07mm. In burns treated at 150\u00b0C for 5, 10, 20, and 30s, respectively, the trend of increasing maximum burn depth with longer thermal exposure is demonstrated.",
"doi": "10.1117/1.2355667",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2006-09-21",
"series_number": "5",
"volume": "11",
"issue": "5",
"pages": "Art. No. 054033"
},
{
"id": "authors:wj841-9jr86",
"collection": "authors",
"collection_id": "wj841-9jr86",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161102-154838756",
"type": "article",
"title": "Correlation transfer equation for ultrasound-modulated multiply scattered light",
"author": [
{
"family_name": "Sakad\u017ei\u0107",
"given_name": "Sava",
"clpid": "Sakad\u017ei\u0107-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In this paper, we develop a temporal correlation transfer equation (CTE) for ultrasound-modulated multiply scattered light. The equation can be used to obtain the time-varying specific intensity of light produced by a nonuniform ultrasound field in optically scattering media that have a heterogeneous distribution of optical parameters. We also develop a Monte Carlo algorithm that can provide the spatial distribution of the optical power spectrum in optically scattering media with focused ultrasound fields, and heterogeneous distributions of optically scattering and absorbing objects. Derivation of the CTE is based on the ladder diagram approximation of the Bethe-Salpeter equation that assumes moderate ultrasound pressures. We expect the CTE to be applicable to a wide spectrum of conditions in the ultrasound-modulated optical tomography of soft biological tissues.",
"doi": "10.1103/PhysRevE.74.036618",
"issn": "1539-3755",
"publisher": "American Physical Society",
"publication": "Physical Review E",
"publication_date": "2006-09",
"series_number": "3",
"volume": "74",
"issue": "3",
"pages": "Art. No. 036618"
},
{
"id": "authors:26292-z8x53",
"collection": "authors",
"collection_id": "26292-z8x53",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-103336409",
"type": "article",
"title": "Intense acoustic bursts as a signal-enhancement mechanism in ultrasound-modulated optical tomography",
"author": [
{
"family_name": "Kim",
"given_name": "Chulhong",
"clpid": "Kim-Chulhong"
},
{
"family_name": "Zemp",
"given_name": "Roger J.",
"clpid": "Zemp-R-J"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Biophotonic imaging with ultrasound-modulated optical tomography (UOT) promises ultrasonically resolved imaging in biological tissues. A key challenge in this imaging technique is a low signal-to-noise ratio (SNR). We show significant UOT signal enhancement by using intense time-gated acoustic bursts. A CCD camera captured the speckle pattern from a laser-illuminated tissue phantom. Differences in speckle contrast were observed when ultrasonic bursts were applied, compared with when no ultrasound was applied. When CCD triggering was synchronized with burst initiation, acoustic-radiation-force-induced displacements were detected. To avoid mechanical contrast in UOT images, the CCD camera acquisition was delayed several milliseconds until transient effects of acoustic radiation force attenuated to a satisfactory level. The SNR of our system was sufficiently high to provide an image pixel per acoustic burst without signal averaging. Because of the substantially improved SNR, the use of intense acoustic bursts is a promising signal enhancement strategy for UOT.",
"doi": "10.1364/OL.31.002423",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2006-08-15",
"series_number": "16",
"volume": "31",
"issue": "16",
"pages": "2423-2425"
},
{
"id": "authors:8pfed-57p86",
"collection": "authors",
"collection_id": "8pfed-57p86",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161109-154531350",
"type": "article",
"title": "In vivo three-dimensional photoacoustic tomography of a whole mouse head",
"author": [
{
"family_name": "Song",
"given_name": "Kwang Hyun",
"clpid": "Song-Kwang-Hyun"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "An in vivo photoacoustic imaging system was designed and implemented to image the entire small animal head. A special scanning gantry was designed to enable in vivo imaging in coronal cross sections with high contrast and good spatial resolution for the first time to our knowledge. By use of a 2.25\u2009MHz ultrasonic transducer with a 6\u2009mm diameter active element, an in-plane radial resolution of \u223c312\u2009 \u00b5m was achieved. Deeply seated arterial and venous vessels in the head measuring up to 1.7\u2009cm in diameter were simultaneously imaged in vivo with 804\u2009nm wavelength laser excitation of photoacoustic waves.",
"doi": "10.1364/OL.31.002453",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2006-08-15",
"series_number": "16",
"volume": "31",
"issue": "16",
"pages": "2453-2455"
},
{
"id": "authors:ch0na-q2s24",
"collection": "authors",
"collection_id": "ch0na-q2s24",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160614-104743666",
"type": "article",
"title": "Functional photoacoustic microscopy for high-resolution and noninvasive in vivo imaging",
"author": [
{
"family_name": "Zhang",
"given_name": "Hao F.",
"clpid": "Zhang-Hao-F"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-Konstantin-I"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-George"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Although optical absorption is strongly associated with the physiological status of biological tissue, existing high-resolution optical imaging modalities, including confocal microscopy, two-photon microscopy and optical coherence tomography, do not sense optical absorption directly. Furthermore, optical scattering prevents these methods from imaging deeper than ~1 mm below the tissue surface. Here we report functional photoacoustic microscopy (fPAM), which provides multiwavelength imaging of optical absorption and permits high spatial resolution beyond this depth limit with a ratio of maximum imaging depth to depth resolution greater than 100. Reflection mode, rather than orthogonal or transmission mode, is adopted because it is applicable to more anatomical sites than the others. fPAM is demonstrated with in vivo imaging of angiogenesis, melanoma, hemoglobin oxygen saturation (sO_2) of single vessels in animals and total hemoglobin concentration in humans.",
"doi": "10.1038/nbt1220",
"issn": "1087-0156",
"publisher": "Nature Publishing Group",
"publication": "Nature Biotechnology",
"publication_date": "2006-07",
"series_number": "7",
"volume": "24",
"issue": "7",
"pages": "848-851"
},
{
"id": "authors:5fc39-7w989",
"collection": "authors",
"collection_id": "5fc39-7w989",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-111327126",
"type": "article",
"title": "Stochastic explanation of speckle contrast detection in ultrasound-modulated optical tomography",
"author": [
{
"family_name": "Zemp",
"given_name": "Roger",
"clpid": "Zemp-R-J"
},
{
"family_name": "Sakad\u017ei\u0107",
"given_name": "Sava",
"clpid": "Sakad\u017ei\u0107-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Ultrasound-modulated optical tomography is an imaging technique that detects ultrasonically tagged light in optically turbid media to obtain images with optical contrast and ultrasonic spatial resolution. A CCD-camera-based speckle contrast detection scheme has been introduced previously to detect modulated light emerging from the ultrasonic sample volume. Differences in speckle contrast were experimentally observed when ultrasound was applied compared to when it was not. In this paper we provide an analytic explanation for this phenomenon and connect speckle statistics with ultrasonic field parameters. The theory predicts that speckle contrast changes linearly with applied acoustic intensity. This prediction is experimentally validated for both 1 and 3.5MHz ultrasound. Signal dependence on ultrasound frequency is discussed.",
"doi": "10.1103/PhysRevE.73.061920",
"issn": "1539-3755",
"publisher": "American Physical Society",
"publication": "Physical Review E",
"publication_date": "2006-06",
"series_number": "6",
"volume": "73",
"issue": "6",
"pages": "Art. No. 061920"
},
{
"id": "authors:8grjw-7f543",
"collection": "authors",
"collection_id": "8grjw-7f543",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-112058482",
"type": "article",
"title": "Temperature distribution in selective laser-tissue interaction",
"author": [
{
"family_name": "Crochet",
"given_name": "Jared J.",
"clpid": "Crochet-J-J"
},
{
"family_name": "Gnyawali",
"given_name": "Surya C.",
"clpid": "Gnyawali-S-C"
},
{
"family_name": "Chen",
"given_name": "Yichao",
"clpid": "Chen-Yichao"
},
{
"family_name": "Lemley",
"given_name": "Evan C.",
"clpid": "Lemley-E-C"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Chen",
"given_name": "Wei R.",
"clpid": "Chen-Wei-R"
}
],
"abstract": "Selective photothermal interaction using dye enhancement has proven to be effective in minimizing surrounding tissue damage and delivering energy to target tissue. During laser irradiation, the process of photon absorption and thermal energy diffusion in the target tissue and its surrounding tissue are crucial. Such information allows the selection of proper operating parameters such as dye concentrations, laser power, and exposure time for optimal therapeutic effect. Combining the Monte Carlo method for energy absorption and the finite difference method for heat diffusion, the temperature distributions in target tissue and surrounding tissue in dye enhanced laser photothermal interaction are obtained. Different tissue configurations and dye enhancement are used in the simulation, and different incident beam sizes are also used to determine optimum beam sizes for various tissue configurations. Our results show that the algorithm developed in this study could predict the thermal outcome of laser irradiation. Our simulation indicates that with appropriate absorption enhancement of the target tissue, the temperature in the target tissue and in the surrounding tissue can be effectively controlled. This method can be used for optimization of lesion treatment using laser photothermal interactions. It may also provide guidance for laser immunotherapy in cancer treatment, since the immunological responses are believed to be related to tissue temperature changes.",
"doi": "10.1117/1.2204615",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2006-05",
"series_number": "3",
"volume": "11",
"issue": "3",
"pages": "Art. No. 034031"
},
{
"id": "authors:6xfcn-zpx39",
"collection": "authors",
"collection_id": "6xfcn-zpx39",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-124511046",
"type": "article",
"title": "Three-dimensional imaging of skin melanoma in vivo by dual-wavelength photoacoustic microscopy",
"author": [
{
"family_name": "Oh",
"given_name": "Jung-Taek",
"clpid": "Oh-Jung-Taek"
},
{
"family_name": "Li",
"given_name": "Meng-Lin",
"clpid": "Li-Meng-Lin"
},
{
"family_name": "Zhang",
"given_name": "Hao F.",
"clpid": "Zhang-Hao-F"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Dual-wavelength reflection-mode photoacoustic microscopy is used to noninvasively obtain three-dimensional (3-D) images of subcutaneous melanomas and their surrounding vasculature in nude mice in vivo. The absorption coefficients of blood and melanin-pigmented melanomas vary greatly relative to each other at these two optical wavelengths (764 and 584nm). Using high-resolution and high-contrast photoacoustic imaging in vivo with a near-infrared (764-nm) light source, the 3-D melanin distribution inside the skin is imaged, and the maximum thickness of the melanoma (\u223c0.5mm) is measured. The vascular system surrounding the melanoma is also imaged with visible light (584nm) and the tumor-feeding vessels found. This technique can potentially be used for melanoma diagnosis, prognosis, and treatment planning.",
"doi": "10.1117/1.2210907",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2006-05",
"series_number": "3",
"volume": "11",
"issue": "3",
"pages": "Art. No. 034032"
},
{
"id": "authors:wxpys-gjr36",
"collection": "authors",
"collection_id": "wxpys-gjr36",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200226-093728901",
"type": "article",
"title": "Correlation Transfer and Diffusion of Ultrasound-Modulated Multiply Scattered Light",
"author": [
{
"family_name": "Sakad\u017ei\u0107",
"given_name": "Sava",
"clpid": "Sakad\u017ei\u0107-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We develop a temporal correlation transfer equation (CTE) and a temporal correlation diffusion equation (CDE) for ultrasound-modulated multiply scattered light. These equations can be applied to an optically scattering medium with embedded optically scattering and absorbing objects to calculate the power spectrum of light modulated by a nonuniform ultrasound field. We present an analytical solution based on the CDE and Monte Carlo simulation results for light modulated by a cylinder of ultrasound in an optically scattering slab. We further validate with experimental measurements the numerical calculations for an actual ultrasound field. The CTE and CDE are valid for moderate ultrasound pressures and on a length scale comparable with the optical transport mean-free path. These equations should be applicable to a wide spectrum of conditions for ultrasound-modulated optical tomography of soft biological tissues.",
"doi": "10.1103/physrevlett.96.163902",
"issn": "0031-9007",
"publisher": "American Physical Society",
"publication": "Physical Review Letters",
"publication_date": "2006-04-28",
"series_number": "16",
"volume": "96",
"issue": "16",
"pages": "Art. No. 163902"
},
{
"id": "authors:n160b-e2x36",
"collection": "authors",
"collection_id": "n160b-e2x36",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-104448307",
"type": "article",
"title": "Photoacoustic imaging in biomedicine",
"author": [
{
"family_name": "Xu",
"given_name": "Minghua",
"clpid": "Xu-Minghua"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic imaging (also called optoacoustic or thermoacoustic imaging) has the potential to image animal or human organs, such as the breast and the brain, with simultaneous high contrast and high spatial resolution. This article provides an overview of the rapidly expanding field of photoacoustic imaging for biomedical applications. Imaging techniques, including depth profiling in layered media, scanning tomography with focused ultrasonic transducers, image forming with an acoustic lens, and computed tomography with unfocused transducers, are introduced. Special emphasis is placed on computed tomography, including reconstruction algorithms, spatial resolution, and related recent experiments. Promising biomedical applications are discussed throughout the text, including (1) tomographic imaging of the skin and other superficial organs by laser-induced photoacoustic microscopy, which offers the critical advantages, over current high-resolution optical imaging modalities, of deeper imaging depth and higher absorptioncontrasts, (2) breast cancerdetection by near-infrared light or radio-frequency\u2013wave-induced photoacoustic imaging, which has important potential for early detection, and (3) small animal imaging by laser-induced photoacoustic imaging, which measures unique optical absorptioncontrasts related to important biochemical information and provides better resolution in deep tissues than optical imaging.",
"doi": "10.1063/1.2195024",
"issn": "0034-6748",
"publisher": "American Institute of Physics",
"publication": "Review of Scientific Instruments",
"publication_date": "2006-04",
"series_number": "4",
"volume": "77",
"issue": "4",
"pages": "Art. No. 041101"
},
{
"id": "authors:2mn6n-dmn97",
"collection": "authors",
"collection_id": "2mn6n-dmn97",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-105245536",
"type": "article",
"title": "Spectral-domain optical coherence tomography: Removal of autocorrelation using an optical switch",
"author": [
{
"family_name": "Ai",
"given_name": "Jun",
"clpid": "Ai-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A novel spectral-domain optical coherence tomography (SD-OCT), in which the self-interferogram of the object wave and the standard SD-OCT interferogram are acquired asynchronously using an optical switch in the reference arm, is presented. After Fourier transformation, the autocorrelation of the object is removed simply by subtraction from the standard SD-OCT image. The measured sensitivity is 103.5dB at z=0.115mm, and it gradually reduces to 84.1dB at z=3.275mm. The axial resolution is 15\u03bcm in the air. In vivo images of human skin are presented to demonstrate the performance of autocorrelation removal.",
"doi": "10.1063/1.2186520",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2006-03-13",
"series_number": "11",
"volume": "88",
"issue": "11",
"pages": "Art. No. 111115"
},
{
"id": "authors:467j6-30h14",
"collection": "authors",
"collection_id": "467j6-30h14",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-103745094",
"type": "article",
"title": "Noninvasive imaging of hemoglobin concentration and oxygenation in the rat brain using high-resolution photoacoustic tomography",
"author": [
{
"family_name": "Wang",
"given_name": "Xueding",
"clpid": "Wang-Xueding"
},
{
"family_name": "Xie",
"given_name": "Xueyi",
"clpid": "Xie-Xueyi"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
}
],
"abstract": "Simultaneous transcranial imaging of two functional parameters, the total concentration of hemoglobin and the hemoglobin oxygen saturation, in the rat brain in vivo is realized noninvasively using laser-based photoacoustic tomography (PAT). As in optical diffusion spectroscopy, PAT can assess the optical absorption of endogenous chromophores, e.g., oxygenated and deoxygenated hemoglobins, at multiple optical wavelengths. However, PAT can provide high spatial resolution because its resolution is diffraction-limited by photoacoustic signals rather than by optical diffusion. Laser pulses at two wavelengths are used sequentially to acquire photoacoustic images of the vasculature in the cerebral cortex of a rat brain through the intact skin and skull. The distributions of blood volume and blood oxygenation in the cerebral cortical venous vessels, altered by systemic physiological modulations including hyperoxia, normoxia, and hypoxia, are visualized successfully with satisfactory spatial resolution. This technique, with its prominent sensitivity to endogenous contrast, can potentially contribute to the understanding of the interrelationship between neural, hemodynamic, and metabolic activities in the brain.",
"doi": "10.1117/1.2192804",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2006-03",
"series_number": "2",
"volume": "11",
"issue": "2",
"pages": "Art. No. 024015"
},
{
"id": "authors:21caq-w8454",
"collection": "authors",
"collection_id": "21caq-w8454",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161102-154340931",
"type": "article",
"title": "A Born-type approximation method for bioluminescence tomography",
"author": [
{
"family_name": "Cong",
"given_name": "Wenxiang",
"clpid": "Cong-Wenxiang"
},
{
"family_name": "Durairaj",
"given_name": "Kumar",
"clpid": "Durairaj-K"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Wang",
"given_name": "Ge",
"clpid": "Wang-Ge"
}
],
"abstract": "In this paper, we present a Born-type approximation method for bioluminescence tomography (BLT), which is to reconstruct an internal bioluminescent source from the measured bioluminescent signal on the external surface of a small animal. Based on the diffusion approximation for the photon propagation in biological tissue, this BLT method utilizes the Green function to establish a linear relationship between the measured bioluminescent signal and the internal bioluminescent source distribution. The Green function can be modified to describe a heterogeneous medium with an arbitrary boundary using the Born approximation. The BLT reconstruction is formulated in a linear least-squares optimization framework with simple bounds constraint. The performance of this method is evaluated in numerical simulation and phantom experiments.",
"doi": "10.1118/1.2168293",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2006-03",
"series_number": "3",
"volume": "33",
"issue": "3",
"pages": "679-686"
},
{
"id": "authors:76zjm-zyf05",
"collection": "authors",
"collection_id": "76zjm-zyf05",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160711-152157636",
"type": "article",
"title": "Rhesus monkey brain imaging through intact skull with thermoacoustic tomography",
"author": [
{
"family_name": "Xu",
"given_name": "Yuan",
"orcid": "0000-0001-9326-2197",
"clpid": "Xu-Yuan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Two-dimensional microwave-induced thermoacoustic tomography (TAT) is applied to imaging the Rhesus monkey brain through the intact skull. To reduce the wavefront distortion caused by the skull, only the low-frequency components of the thermoacoustic signals (< 1 MHz) are used to reconstruct the TAT images. The methods of signal processing and image reconstruction are validated by imaging a lamb kidney. The resolution of the system is found to be 4 mm when we image a 1-month-old monkey head containing inserted needles. We also image the coronal and axial sections of a 7-month-old monkey head. Brain features that are 3 cm deep in the head are imaged clearly. Our results demonstrate that TAT has potential for use in portable, cost-effective imagers for pediatric brains.",
"doi": "10.1109/TUFFC.2006.1610562",
"issn": "0885-3010",
"publisher": "IEEE",
"publication": "IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control",
"publication_date": "2006-03",
"series_number": "3",
"volume": "53",
"issue": "3",
"pages": "542-548"
},
{
"id": "authors:bxab0-gz129",
"collection": "authors",
"collection_id": "bxab0-gz129",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161109-153322464",
"type": "article",
"title": "Improved in vivo photoacoustic microscopy based on a virtual-detector concept",
"author": [
{
"family_name": "Li",
"given_name": "Meng-Lin",
"clpid": "Li-Meng-Lin"
},
{
"family_name": "Zhang",
"given_name": "Hao F.",
"clpid": "Zhang-Hao-F"
},
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Recently an in vivo high-resolution backward-mode photoacoustic microscope was developed that shows potential for applications in dermatology and related cancer research. However, the limited depth of focus of the large-numerical-aperture (NA) ultrasonic lens employed in this system causes the image quality to deteriorate significantly in the out-of-focus region. To solve this problem, we devised and explored, for the first time to our knowledge, a virtual-detector-based synthetic-aperture focusing technique, combined with coherence weighting, for photoacoustic microscopy with such a large-NA transducer. Images of phantoms show that the proposed technique improves the \u22126\u2009dB\u22126\u2009dB lateral resolution from 49\u2013379 to 46\u201353",
"doi": "10.1364/OL.31.000474",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2006-02-15",
"series_number": "4",
"volume": "31",
"issue": "4",
"pages": "474-476"
},
{
"id": "authors:3mp1p-cad68",
"collection": "authors",
"collection_id": "3mp1p-cad68",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-151500283",
"type": "article",
"title": "Synchronous self-elimination of autocorrelation interference in Fourier-domain optical coherence tomography",
"author": [
{
"family_name": "Ai",
"given_name": "Jun",
"clpid": "Ai-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have developed a new algorithm and configuration for self-eliminating the autocorrelation of the object wave in Fourier-domain optical coherence tomography. A self-interferogram of the object wave is acquired synchronously with the standard interferogram of the recombined object and reference waves. The former is then subtracted from the latter after Fourier transformation. The algorithm is validated by numerical simulation and by experimental measurement of a U.S. Air Force target and a feline eye.",
"doi": "10.1364/OL.30.002939",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2005-11-01",
"series_number": "21",
"volume": "30",
"issue": "21",
"pages": "2939-2941"
},
{
"id": "authors:kbhnr-9pc57",
"collection": "authors",
"collection_id": "kbhnr-9pc57",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160711-133809050",
"type": "article",
"title": "Thermoacoustic and Photoacoustic Tomography of Thick Biological Tissues toward Breast Imaging",
"author": [
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Fornage",
"given_name": "Bruno D.",
"clpid": "Fornage-B-D"
},
{
"family_name": "Jin",
"given_name": "Xing",
"clpid": "Jin-Xing"
},
{
"family_name": "Xu",
"given_name": "Minghua",
"clpid": "Xu-Minghua"
},
{
"family_name": "Hunt",
"given_name": "Kelly K.",
"clpid": "Hunt-K-K"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Microwave-based thermoacoustic tomography (TAT) and laser-based photoacoustic tomography (PAT) in a circular scanning configuration were both developed to image deeply seated lesions and objects in biological tissues. Because malignant breast tissue absorbs microwaves more strongly than benign breast tissue, cancers were imaged with good spatial resolution and contrast by TAT in human breast mastectomy specimens. Based on the intrinsic optical contrast between blood and chicken breast muscle, an embedded blood object that was 5 cm deep in the tissue was also detected using PAT at a wavelength of 1064 nm.",
"doi": "10.1177/153303460500400509",
"issn": "1533-0346",
"publisher": "SAGE Publications",
"publication": "Technology in Cancer Research and Treatment",
"publication_date": "2005-10",
"series_number": "5",
"volume": "4",
"issue": "5",
"pages": "559-565"
},
{
"id": "authors:04gkt-twe29",
"collection": "authors",
"collection_id": "04gkt-twe29",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-125743785",
"type": "article",
"title": "Fiber-based polarization-sensitive Mueller matrix optical coherence tomography with continuous source polarization modulation",
"author": [
{
"family_name": "Jiao",
"given_name": "Shuliang",
"clpid": "Jiao-Shuliang"
},
{
"family_name": "Todorovi\u0107",
"given_name": "Milo\u0161",
"clpid": "Todorovi\u0107-M"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We report on a new configuration of fiber-based polarization-sensitive Mueller matrix optical coherence tomography that permits the acquisition of the round-trip Jones matrix of a biological sample using only one light source and a single depth scan. In this new configuration, a polarization modulator is used in the source arm to continuously modulate the incident polarization state for both the reference and the sample arms. The Jones matrix of the sample can be calculated from the two frequency terms in the two detection channels. The first term is modulated by the carrier frequency, which is determined by the longitudinal scanning mechanism, whereas the other term is modulated by the beat frequency between the carrier frequency and the second harmonic of the modulation frequency of the polarization modulator. One important feature of this system is that, for the first time to our knowledge, the Jones matrix of the sample can be calculated with a single detection channel and a single measurement when diattenuation is negligible. The system was successfully tested by imaging both standard polarization elements and biological samples.",
"doi": "10.1364/AO.44.005463",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2005-09-10",
"series_number": "26",
"volume": "44",
"issue": "26",
"pages": "5463-5467"
},
{
"id": "authors:k66jb-ygm92",
"collection": "authors",
"collection_id": "k66jb-ygm92",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-134400405",
"type": "article",
"title": "Practical reconstruction method for bioluminescence tomography",
"author": [
{
"family_name": "Cong",
"given_name": "Wenxiang",
"clpid": "Cong-Wenxiang"
},
{
"family_name": "Wang",
"given_name": "Ge",
"clpid": "Wang-Ge"
},
{
"family_name": "Kumar",
"given_name": "Durairaj",
"clpid": "Kumar-Durairaj"
},
{
"family_name": "Liu",
"given_name": "Yi",
"clpid": "Liu-Yi"
},
{
"family_name": "Jiang",
"given_name": "Ming",
"clpid": "Jiang-Ming"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Hoffman",
"given_name": "Eric A.",
"clpid": "Hoffman-E-A"
},
{
"family_name": "McLennan",
"given_name": "Geoffrey",
"clpid": "McLennan-G"
},
{
"family_name": "McCray",
"given_name": "Paul B.",
"clpid": "McCray-P-B"
},
{
"family_name": "Zabner",
"given_name": "Joseph",
"clpid": "Zabner-J"
},
{
"family_name": "Cong",
"given_name": "Alexander",
"clpid": "Cong-Alexander"
}
],
"abstract": "Bioluminescence tomography (BLT) is used to localize and quantify bioluminescent sources in a small living animal. By advancing bioluminescent imaging to a tomographic framework, it helps to diagnose diseases, monitor therapies and facilitate drug development. In this paper, we establish a direct linear relationship between measured surface photon density and an unknown bioluminescence source distribution by using a finite-element method based on the diffusion approximation to the photon propagation in biological tissue. We develop a novel reconstruction algorithm to recover the source distribution. This algorithm incorporates a priori knowledge to define the permissible source region in order to enhance numerical stability and efficiency. Simulations with a numerical mouse chest phantom demonstrate the feasibility of the proposed BLT algorithm and reveal its performance in terms of source location, density, and robustness against noise. Lastly, BLT experiments are performed to identify the location and power of two light sources in a physical mouse chest phantom.",
"doi": "10.1364/OPEX.13.006756",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "2005-09-05",
"series_number": "18",
"volume": "13",
"issue": "18",
"pages": "6756-6771"
},
{
"id": "authors:t5jtt-n3f98",
"collection": "authors",
"collection_id": "t5jtt-n3f98",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-134014258",
"type": "article",
"title": "Modulation of multiply scattered coherent light by ultrasonic pulses: An analytical model",
"author": [
{
"family_name": "Sakad\u017ei\u0107",
"given_name": "Sava",
"clpid": "Sakad\u017ei\u0107-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present an analytical solution for the acousto-optical modulation of multiply scattered light in a medium irradiated with a train of ultrasound pulses. Previous theory is extended to cases where the ultrasound-induced optical phase increments between the different scattering events are strongly correlated, and it is shown that the approximate similarity relation still holds. The relation between the ultrasound induced motions of the background fluid and the optical scatterers is generalized, and it is shown that correlation exists between the optical phase increments that are due to the scatterer movement and the optical phase increments that are due to the modulation of the optical index of refraction. Finally, it is shown that compared with the spectrum of ultrasound pulses, the power spectral density of acousto-optically modulated light is strongly attenuated at the higher ultrasound frequencies.",
"doi": "10.1103/PhysRevE.72.036620",
"issn": "1539-3755",
"publisher": "American Physical Society",
"publication": "Physical Review E",
"publication_date": "2005-09",
"series_number": "3",
"volume": "72",
"issue": "3",
"pages": "Art. No. 036620"
},
{
"id": "authors:nankj-gn314",
"collection": "authors",
"collection_id": "nankj-gn314",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-152255423",
"type": "article",
"title": "Weighted expectation maximization reconstruction algorithms for thermoacoustic tomography",
"author": [
{
"family_name": "Zhang",
"given_name": "Jin",
"clpid": "Zhang-Jin"
},
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
},
{
"family_name": "Pan",
"given_name": "Xiaochuan",
"clpid": "Pan-Xiaochuan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Thermoacoustic tomography (TAT) is an emerging imaging technique with potential for a wide range of biomedical imaging applications. In this correspondence, we propose an infinite family of weighted expectation maximization (EM) algorithms for reconstruction of images from temporally truncated TAT measurement data. The weighted EM algorithms are equivalent mathematically to the conventional EM algorithm, but are shown to propagate data inconsistencies in different ways. Using simulated and experimental TAT measurement data, we demonstrate that suitable choices of weighted EM algorithms can effectively mitigate image artifacts that are attributable to temporal truncation of the TAT data function.",
"doi": "10.1109/TMI.2005.848372",
"issn": "0278-0062",
"publisher": "IEEE",
"publication": "IEEE Transactions on Medical Imaging",
"publication_date": "2005-06",
"series_number": "6",
"volume": "24",
"issue": "6",
"pages": "817-820"
},
{
"id": "authors:ycjy7-7cp16",
"collection": "authors",
"collection_id": "ycjy7-7cp16",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-095623519",
"type": "article",
"title": "In vivo dark-field reflection-mode photoacoustic microscopy",
"author": [
{
"family_name": "Maslov",
"given_name": "Konstantin",
"orcid": "0000-0003-3408-8840",
"clpid": "Maslov-K-I"
},
{
"family_name": "Stoica",
"given_name": "Gheorghe",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Reflection-mode photoacoustic microscopy with dark-field laser pulse illumination and high-numerical-aperture ultrasonic detection is designed and implemented in noninvasively imaged blood vessels in the skin in vivo. Dark-field optical illumination minimizes the interference caused by strong photoacoustic signals from superficial structures. A high-numerical-aperture acoustic lens provides high lateral resolution, 45\u2013120\u03bcm in this system. A broadband ultrasonic detection system provides high axial resolution, estimated to be \u223c15\u03bcm. The optical illumination and ultrasonic detection are in a coaxial confocal configuration for optimal image quality. The system is capable of imaging optical-absorption contrast as deep as 3mm in biological tissue.",
"doi": "10.1364/OL.30.000625",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2005-03-15",
"series_number": "6",
"volume": "30",
"issue": "6",
"pages": "625-627"
},
{
"id": "authors:m289g-zzb69",
"collection": "authors",
"collection_id": "m289g-zzb69",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-125233243",
"type": "article",
"title": "Deeply penetrating photoacoustic tomography in biological tissues enhanced with an optical contrast agent",
"author": [
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography (PAT) in a circular scanning configuration was developed to image deeply embedded optical heterogeneity in biological tissues. While the optical penetration was maximized with near-infrared laser pulses of 800-nm wavelength, the optical contrast was enhanced by Indocyanine Green (ICG) dye whose absorption peak matched the laser wavelength. This optimized PAT was able to image objects embedded at depths of as much as 5.2 cm, 6.2 times the 1/e optical penetration depth, in chicken breast muscle at a resolution of <780 \u00b5m and a sensitivity of <7 pmol of ICG in blood. The resolution was found to deteriorate slowly with increasing imaging depth. The effects of detection bandwidth on the quality of images acquired simultaneously by four different ultrasonic transducers are described.",
"doi": "10.1364/OL.30.000507",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2005-03-01",
"series_number": "5",
"volume": "30",
"issue": "5",
"pages": "507-509"
},
{
"id": "authors:mxswv-01m96",
"collection": "authors",
"collection_id": "mxswv-01m96",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-132914808",
"type": "article",
"title": "Looking and listening to light: the evolution of whole-body photonic imaging",
"author": [
{
"family_name": "Ntziachristos",
"given_name": "Vasilis",
"clpid": "Ntziachristos-V"
},
{
"family_name": "Ripoll",
"given_name": "Jorge",
"clpid": "Ripoll-J"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Weissleder",
"given_name": "Ralph",
"clpid": "Weissleder-R"
}
],
"abstract": "Optical imaging of live animals has grown into an important tool in biomedical research as advances in photonic technology and reporter strategies have led to widespread exploration of biological processes in vivo. Although much attention has been paid to microscopy, macroscopic imaging has allowed small-animal imaging with larger fields of view (from several millimeters to several centimeters depending on implementation). Photographic methods have been the mainstay for fluorescence and bioluminescence macroscopy in whole animals, but emphasis is shifting to photonic methods that use tomographic principles to noninvasively image optical contrast at depths of several millimeters to centimeters with high sensitivity and sub-millimeter to millimeter resolution. Recent theoretical and instrumentation advances allow the use of large data sets and multiple projections and offer practical systems for quantitative, three-dimensional whole-body images. For photonic imaging to fully realize its potential, however, further progress will be needed in refining optical inversion methods and data acquisition techniques.",
"doi": "10.1038/nbt1074",
"issn": "1087-0156",
"publisher": "Nature Publishing Group",
"publication": "Nature Biotechnology",
"publication_date": "2005-03",
"series_number": "3",
"volume": "23",
"issue": "3",
"pages": "313-320"
},
{
"id": "authors:f3841-y2m64",
"collection": "authors",
"collection_id": "f3841-y2m64",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-132318724",
"type": "article",
"title": "Imaging of tumor angiogenesis in rat brains in vivo by photoacoustic tomography",
"author": [
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Xueding",
"clpid": "Wang-Xueding"
},
{
"family_name": "Xie",
"given_name": "Xueyi",
"clpid": "Xie-Xueyi"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Green laser pulses at a wavelength of 532 nm from a Q-switched Nd:YAG laser were employed as irradiation sources for photoacoustic tomography (PAT). The vascular structure of the brain was imaged clearly, with optimal contrast, because blood has strong absorption near this wavelength. The photoacoustic images of rat brain tumors in this study clearly reveal the angiogenesis that is associated with tumors. Brain tumors can be identified based on the distorted vascular architecture of brain tumorigenesis and related vascular changes, such as hemorrhage. This research demonstrates that PAT can potentially provide a powerful tool for small-animal biological research.",
"doi": "10.1364/AO.44.000770",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2005-02-10",
"series_number": "5",
"volume": "44",
"issue": "5",
"pages": "770-775"
},
{
"id": "authors:b5vmm-92v87",
"collection": "authors",
"collection_id": "b5vmm-92v87",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-130710638",
"type": "article",
"title": "Half-time image reconstruction in thermoacoustic tomography",
"author": [
{
"family_name": "Anastasio",
"given_name": "Mark A.",
"orcid": "0000-0002-3192-4172",
"clpid": "Anastasio-M-A"
},
{
"family_name": "Zhang",
"given_name": "Jin",
"clpid": "Zhang-Jin"
},
{
"family_name": "Pan",
"given_name": "Xiaochuan",
"clpid": "Pan-Xiaochuan"
},
{
"family_name": "Zou",
"given_name": "Yu",
"clpid": "Zou-Yu"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Thermoacoustic tomography (TAT) is an emerging imaging technique with great potential for a wide range of biomedical imaging applications. We propose and investigate reconstruction approaches for TAT that are based on the half-time reflectivity tomography paradigm. We reveal that half-time reconstruction approaches permit for the explicit control of statistically complementary information that can result in the optimal reduction of image variances. We also show that half-time reconstruction approaches can mitigate image artifacts due to heterogeneous acoustic properties of an object. Reconstructed images and numerical results produced from simulated and experimental TAT measurement data are employed to demonstrate these effects.",
"doi": "10.1109/TMI.2004.839682",
"issn": "0278-0062",
"publisher": "IEEE",
"publication": "IEEE Transactions on Medical Imaging",
"publication_date": "2005-02",
"series_number": "2",
"volume": "24",
"issue": "2",
"pages": "199-210"
},
{
"id": "authors:8vsyr-zwm40",
"collection": "authors",
"collection_id": "8vsyr-zwm40",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160614-111706935",
"type": "article",
"title": "Universal back-projection algorithm for photoacoustic computed tomography",
"author": [
{
"family_name": "Xu",
"given_name": "Minghua",
"clpid": "Xu-Minghua"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We report results of a reconstruction algorithm for three-dimensional photoacoustic computed tomography. A universal back-projection formula is presented for three types of imaging geometries: planar, spherical, and cylindrical surfaces. A solid-angle weighting factor is introduced in the back-projection formula to compensate for the variations of detection views. A method for implementing this algorithm is described. Numerical simulation is used to demonstrate the performance of the algorithm.",
"doi": "10.1103/PhysRevE.71.016706",
"issn": "1539-3755",
"publisher": "American Physical Society",
"publication": "Physical Review E",
"publication_date": "2005-01",
"series_number": "1",
"volume": "71",
"issue": "1",
"pages": "Art. No. 016706"
},
{
"id": "authors:29r8d-mcy52",
"collection": "authors",
"collection_id": "29r8d-mcy52",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-131815944",
"type": "article",
"title": "Imaging of high-intensity focused ultrasound-induced lesions in soft biological tissue using thermoacoustic tomography",
"author": [
{
"family_name": "Jin",
"given_name": "Xing",
"clpid": "Jin-Xing"
},
{
"family_name": "Xu",
"given_name": "Yuan",
"orcid": "0000-0001-9326-2197",
"clpid": "Xu-Yuan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Fang",
"given_name": "Yuncai R.",
"clpid": "Fang-Y-R"
},
{
"family_name": "Zanelli",
"given_name": "Claudio I.",
"clpid": "Zanelli-C-I"
},
{
"family_name": "Howard",
"given_name": "Samuel M.",
"clpid": "Howard-S-M"
}
],
"abstract": "An imaging technology, thermoacoustic tomograpy (TAT), was applied to the visualization of high-intensity focused ultrasound (HIFU)-induced lesions. A single, spherically focused ultrasonic transducer, operating at a central frequency of approximately 4 MHz, was used to generate a HIFU field in fresh porcine muscle.Microwave pulses from a 3-GHz microwave generator were then employed to generate thermoacoustic sources in this tissue sample. The thermoacoustic signals were detected by an unfocused ultrasonic transducer that was scanned around the sample. To emphasize the boundaries between the lesion and its surrounding tissue, a local-tomography-type reconstruction method was applied to reconstruct the TAT images of the lesions. Good contrast was obtained between the lesion and the tissue surrounding it. Gross pathologic photographs of the tissue samples confirmed the TAT images.This work demonstrates that TAT may potentially be used to image HIFU-induced lesions in biological tissues.",
"doi": "10.1118/1.1829403",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2005-01",
"series_number": "1",
"volume": "32",
"issue": "1",
"pages": "5-11"
},
{
"id": "authors:n737p-6a992",
"collection": "authors",
"collection_id": "n737p-6a992",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161207-143311078",
"type": "article",
"title": "Reply to Comment on \"Optical-fiber-based Mueller optical coherence tomography\"",
"author": [
{
"family_name": "Jiao",
"given_name": "Shuliang",
"clpid": "Jiao-Shuliang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We reply to the comments by Park et al. [Opt. Lett. 29, 2873 (2004)] about our previous Letter [Opt. Lett. 28, 1206 (2003)].",
"doi": "10.1364/OL.29.002875",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2004-12-15",
"series_number": "24",
"volume": "29",
"issue": "24",
"pages": "2875-2877"
},
{
"id": "authors:gc5yk-fjt83",
"collection": "authors",
"collection_id": "gc5yk-fjt83",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161207-145146291",
"type": "article",
"title": "High-resolution ultrasound-modulated optical tomography in biological tissues",
"author": [
{
"family_name": "Sakad\u017ei\u0107",
"given_name": "Sava",
"clpid": "Sakad\u017ei\u0107-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present a novel implementation of high-resolution ultrasound-modulated optical tomography that, based on optical contrast, can image several millimeters deep into soft biological tissues. A long-cavity confocal Fabry\u2013Perot interferometer, which provides a large etendue and a short response time, was used to detect the ultrasound-modulated coherent light that traversed the scattering biological tissue. Using 15-MHz ultrasound, we imaged with high-contrast light-absorbing structures placed >\n3 mm below the surface of chicken breast tissue. The resolution along the axial and the lateral directions with respect to the ultrasound propagation direction was better than 70 and 120 \u00b5m, respectively. The resolution can be scaled down further by use of higher ultrasound frequencies. This technology is complementary to other imaging technologies, such as confocal microscopy and optical-coherence tomography, and has the potential for broad biomedical applications.",
"doi": "10.1364/OL.29.002770",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2004-12-01",
"series_number": "23",
"volume": "29",
"issue": "23",
"pages": "2770-2772"
},
{
"id": "authors:3pejf-nn446",
"collection": "authors",
"collection_id": "3pejf-nn446",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161207-143714667",
"type": "article",
"title": "Comparison of human skin opto-thermal response to near-infrared and visible laser irradiations: a theoretical investigation",
"author": [
{
"family_name": "Dai",
"given_name": "Tianhong",
"clpid": "Dai-Tianhong"
},
{
"family_name": "Pikkula",
"given_name": "Brian M.",
"clpid": "Pikkula-B-M"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Anvari",
"given_name": "Bahman",
"clpid": "Anvari-B"
}
],
"abstract": "Near-infrared wavelengths are absorbed less by epidermal melanin, and penetrate deeper into human skin dermis and blood than visible wavelengths. Therefore, laser irradiation using near-infrared wavelengths may improve the therapeutic outcome of cutaneous hyper-vascular malformations in moderately to heavily pigmented skin patients and those with large-sized blood vessels or blood vessels extending deeply into the skin. A mathematical model composed of a Monte Carlo algorithm to estimate the distribution of absorbed light, numerical solution of a bio-heat diffusion equation to calculate the transient temperature distribution, and a damage integral based on an empirical Arrhenius relationship to quantify the tissue damage was utilized to investigate the opto-thermal response of human skin to near-infrared and visible laser irradiations in conjunction with cryogen spray cooling. In addition, the thermal effects of a single continuous laser pulse and micropulse-composed laser pulse profiles were compared. Simulation results indicated that a 940 nm wavelength induces improved therapeutic outcome compared with a 585 and 595 nm wavelengths for the treatment of patients with large-sized blood vessels and moderately to heavily pigmented skin. On the other hand, a 585 nm wavelength shows the best efficacy in treating small-sized blood vessels, as characterized by the largest laser-induced blood vessel damage depth compared with 595 and 940 nm wavelengths. Dermal blood content has a considerable effect on the threshold incident dosage for epidermal damage, while the effect of blood vessel size is minimal. For the same macropulse duration and incident dosage, a micropulse-composed pulse profile results in higher peak temperature at the basal layer of skin epidermis than an ideal single continuous pulse profile.",
"doi": "10.1088/0031-9155/49/21/002",
"issn": "0031-9155",
"publisher": "IOP",
"publication": "Physics in Medicine and Biology",
"publication_date": "2004-11-07",
"series_number": "21",
"volume": "49",
"issue": "21",
"pages": "4861-4877"
},
{
"id": "authors:8p1jg-n1d43",
"collection": "authors",
"collection_id": "8p1jg-n1d43",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161207-144806440",
"type": "article",
"title": "Determination of local polarization properties of biological samples in the presence of diattenuation by use of Mueller optical coherence tomography",
"author": [
{
"family_name": "Todorovi\u0107",
"given_name": "Milo\u0161",
"clpid": "Todorovi\u0107-M"
},
{
"family_name": "Jiao",
"given_name": "Shuliang",
"clpid": "Jiao-Shuliang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
}
],
"abstract": "A unique feature of polarization-sensitive Mueller optical coherence tomography is that, by measuring Jones or Mueller matrices, it can reveal the complete polarization properties of biological samples, even in the presence of diattenuation. We map local polarization properties for the first time to our knowledge by using polar decomposition in combination with least-squares fitting to differentiate measured integrated Jones matrices with respect to depth. We also introduce the new concept of dual attenuation coefficients to characterize diattenuation per unit infinitesimal length in tissues. We experimentally verify the algorithm using measurements of a section of porcine tendon and the septum of a rat heart.",
"doi": "10.1364/OL.29.002402",
"issn": "0146-9592",
"publisher": "optic",
"publication": "Optics Letters",
"publication_date": "2004-10-15",
"series_number": "20",
"volume": "29",
"issue": "20",
"pages": "2402-2404"
},
{
"id": "authors:edpsk-dhy33",
"collection": "authors",
"collection_id": "edpsk-dhy33",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161207-155728543",
"type": "article",
"title": "Photoacoustic Tomography of a Nanoshell Contrast Agent in the in Vivo Rat Brain",
"author": [
{
"family_name": "Wang",
"given_name": "Yiwen",
"clpid": "Wang-Yiwen"
},
{
"family_name": "Xie",
"given_name": "Xueyi",
"clpid": "Xie-Xueyi"
},
{
"family_name": "Wang",
"given_name": "Xueding",
"clpid": "Wang-Xueding"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Gill",
"given_name": "Kelly L.",
"clpid": "Gill-Sharp-K-L"
},
{
"family_name": "O'Neal",
"given_name": "D. Patrick",
"clpid": "O'Neal-D-P"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "This study demonstrates the feasibility of using nanoshells in vivo as a new contrast-enhancing agent for photoacoustic tomography. Deep penetrating near-infrared light was employed to image the in vivo distribution of poly(ethylene glycol)-coated nanoshells circulating in the vasculature of a rat brain. The images, captured after three sequential administrations of nanoshells, present a gradual enhancement of the optical absorption in the brain vessels by up to 63%. Subsequent clearance of the nanoshells from the blood was imaged for \u223c6 h after the administrations.",
"doi": "10.1021/nl049126a",
"issn": "1530-6984",
"publisher": "American Chemical Society",
"publication": "Nano Letters",
"publication_date": "2004-09",
"series_number": "9",
"volume": "4",
"issue": "9",
"pages": "1689-1692"
},
{
"id": "authors:ezhaz-j5d17",
"collection": "authors",
"collection_id": "ezhaz-j5d17",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161118-154904816",
"type": "article",
"title": "A mouse optical simulation environment (MOSE) to investigate bioluminescent phenomena in the living mouse with the monte carlo method",
"author": [
{
"family_name": "Li",
"given_name": "Hui",
"clpid": "Li-Hui"
},
{
"family_name": "Tian",
"given_name": "Jie",
"clpid": "Tian-Jie"
},
{
"family_name": "Zhu",
"given_name": "Fuping",
"clpid": "Zhu-Fuping"
},
{
"family_name": "Cong",
"given_name": "Wenxiang",
"clpid": "Cong-Wenxiang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Hoffman",
"given_name": "Eric A.",
"clpid": "Hoffman-E-A"
},
{
"family_name": "Wang",
"given_name": "Ge",
"clpid": "Wang-Ge"
}
],
"abstract": "Rationale and objectives:\n\nAs an important part of bioluminescence tomography, which is a newly developed optical imaging modality, mouse optical simulation environment (MOSE) is developed to simulate bioluminescent phenomena in the living mouse and to predict bioluminescent signals detectable outside the mouse. This simulator is dedicated to small animal optical imaging based on bioluminescence.\n\nMaterials and methods:\n\nWith the parameters of biological tissues, bioluminescent sources, and charge coupled device (CCD) detectors, the 2-dimensional/3-dimensional MOSE simulates the whole process of the light propagation in 2-dimensional/3-dimensional biological tissues using the Monte Carlo method. Both the implementation details and the software architecture are described in this article.\n\nResults:\n\nThe software system is implemented in the Visual C++ programming language with the OpenGL techniques and has a user-friendly interface facilitating interactions relevant to bioluminescent imaging. The accuracy of the system is verified by comparing the MOSE results with independent data from analytic solutions and commercial software.\n\nConclusion:\n\nAs shown in our simulation and analysis, the MOSE is accurate, flexible, and efficient to simulate the photon propagation for bioluminescence tomography. With graduate refinements and enhancements, it is hoped that the MOSE will become a standard tool for bioluminescence tomography.",
"doi": "10.1016/j.acra.2004.05.021",
"issn": "1076-6332",
"publisher": "Elsevier",
"publication": "Academic Radiology",
"publication_date": "2004-09",
"series_number": "9",
"volume": "11",
"issue": "9",
"pages": "1029-1038"
},
{
"id": "authors:f200h-fzw91",
"collection": "authors",
"collection_id": "f200h-fzw91",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190304-125703035",
"type": "article",
"title": "Formulation of photon diffusion from spherical bioluminescent sources in an infinite homogeneous medium",
"author": [
{
"family_name": "Cong",
"given_name": "Wenxiang",
"clpid": "Cong-Wenxiang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Wang",
"given_name": "Ge",
"clpid": "Wang-Ge"
}
],
"abstract": "Background: The bioluminescent enzyme firefly luciferase (Luc) or variants of green fluorescent protein (GFP) in transformed cells can be effectively used to reveal molecular and cellular features of neoplasia in vivo. Tumor cell growth and regression in response to various therapies can be evaluated by using bioluminescent imaging. In bioluminescent imaging, light propagates in highly scattering tissue, and the diffusion approximation is sufficiently accurate to predict the imaging signal around the biological tissue. The numerical solutions to the diffusion equation take large amounts of computational time, and the studies for its analytic solutions have attracted more attention in biomedical engineering applications. \n\nMethods: Biological tissue is a turbid medium that both scatters and absorbs photons. An accurate model for the propagation of photons through tissue can be adopted from transport theory, and its diffusion approximation is applied to predict the imaging signal around the biological tissue. The solution to the diffusion equation is formulated by the convolution between its Green's function and source term. The formulation of photon diffusion from spherical bioluminescent sources in an infinite homogeneous medium can be obtained to accelerate the forward simulation of bioluminescent phenomena. \n\nResults: The closed form solutions have been derived for the time-dependent diffusion equation and the steady-state diffusion equation with solid and hollow spherical sources in a homogeneous medium, respectively. Meanwhile, the relationship between solutions with a solid sphere source and ones with a surface sphere source is obtained. \n\nConclusion: We have formulated solutions for the diffusion equation with solid and hollow spherical sources in an infinite homogeneous medium. These solutions have been verified by Monte Carlo simulation for use in biomedical optical imaging studies. The closed form solution is highly accurate and more computationally efficient in biomedical engineering applications. By using our analytic solutions for spherical sources, we can better predict bioluminescent signals and better understand both the potential for, and the limitations of, bioluminescent tomography in an idealized case. The formulas are particularly valuable for furthering the development of bioluminescent tomography.",
"doi": "10.1186/1475-925x-3-12",
"pmcid": "PMC421737",
"issn": "1475-925X",
"publisher": "Springer Nature",
"publication": "BioMedical Engineering OnLine",
"publication_date": "2004-05-04",
"volume": "3",
"pages": "Art. No. 12"
},
{
"id": "authors:q5smf-q2245",
"collection": "authors",
"collection_id": "q5smf-q2245",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170131-102047846",
"type": "article",
"title": "Skin cancer detection by spectroscopic oblique-incidence reflectometry: classification and physiological origins",
"author": [
{
"family_name": "Garcia-Uribe",
"given_name": "Alejandro",
"clpid": "Garcia-Uribe-A"
},
{
"family_name": "Kehtarnavaz",
"given_name": "Nasser",
"clpid": "Kehtarnavaz-N"
},
{
"family_name": "Marquez",
"given_name": "Guillermo",
"clpid": "Marquez-G"
},
{
"family_name": "Prieto",
"given_name": "Victor",
"clpid": "Prieto-V-G"
},
{
"family_name": "Duvic",
"given_name": "Madeleine",
"clpid": "Duvic-M"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Data obtained from 102 skin lesions in vivo by spectroscopic oblique-incidence reflectometry were analyzed. The participating physicians initially divided the skin lesions into two visually distinguishable groups based on the lesions' melanocytic conditions. Group 1 consisted of the following two cancerous and benign subgroups: (1) basal cell carcinomas and squamous cell carcinomas and (2) benign actinic keratoses, seborrheic keratoses, and warts. Group 2 consisted of (1) dysplastic nevi and (2) benign common nevi. For each group, a bootstrap-based Bayes classifier was designed to separate the benign from the dysplastic or cancerous tissues. A genetic algorithm was then used to obtain the most effective combination of spatiospectral features for each classifier. The classifiers, tested with prospective blind studies, reached statistical accuracies of 100% and 95% for groups 1 and 2, respectively. Properties that related to cell-nuclear size, to the concentration of oxyhemoglobin, and to the concentration of deoxyhemoglobin as well as the derived concentration of total hemoglobin and oxygen saturation were defined to explain the origins of the classification outcomes.",
"doi": "10.1364/AO.43.002643",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2004-05-01",
"series_number": "13",
"volume": "43",
"issue": "13",
"pages": "2643-2650"
},
{
"id": "authors:a1r6z-83746",
"collection": "authors",
"collection_id": "a1r6z-83746",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161207-145717339",
"type": "article",
"title": "Multiple-bandwidth photoacoustic tomography",
"author": [
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Xueding",
"clpid": "Wang-Xueding"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Photoacoustic tomography, also referred to as optoacoustic tomography, employs short laser pulses to generate ultrasonic waves in biological tissues. The reconstructed images can be characterized by the convolution of the structure of samples, the laser pulse and the impulse response of the ultrasonic transducer used for detection. Although the laser-induced ultrasonic waves cover a wide spectral range, a single transducer can receive only part of the spectrum because of its limited bandwidth. To systematically analyse this problem, we constructed a photoacoustic tomographic system that uses multiple ultrasonic transducers simultaneously, each at a different central frequency. The photoacoustic images associated with the different transducers were compared and analysed. The system was tested by imaging both mouse brains and phantom samples. The vascular vessels in the brain were revealed by all of the transducers, but the image resolutions differed. The higher frequency detectors provided better image resolution while the lower frequency detectors delineated the major structural traits with a higher signal\u2013noise ratio.",
"doi": "10.1088/0031-9155/49/7/018",
"issn": "0031-9155",
"publisher": "IOP",
"publication": "Physics in Medicine and Biology",
"publication_date": "2004-04-07",
"series_number": "7",
"volume": "49",
"issue": "7",
"pages": "1329-1338"
},
{
"id": "authors:4fzft-hpd10",
"collection": "authors",
"collection_id": "4fzft-hpd10",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161207-150017901",
"type": "article",
"title": "Noninvasive photoacoustic angiography of animal brains in vivo with near-infrared light and an optical contrast agent",
"author": [
{
"family_name": "Wang",
"given_name": "Xueding",
"clpid": "Wang-Xueding"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wegiel",
"given_name": "Malgorzata A.",
"clpid": "Wegiel-M-A"
},
{
"family_name": "Bornhop",
"given_name": "Darryl J.",
"clpid": "Bornhop-D-J"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical contrast agents have been widely applied to enhance the sensitivity and specificity of optical imaging with near-infrared (NIR) light. However, because of the overwhelming scattering of light in biological tissues, the spatial resolution of traditional optical imaging degrades drastically as the imaging depth increases. Here, for the first time to our knowledge, we present noninvasive photoacoustic angiography of animal brains in vivo with NIR light and an optical contrast agent. When indocyanine green polyethylene glycol, a novel absorption dye with prolonged clearance, is injected into the circulatory system of a rat, it obviously enhances the absorption contrast between the blood vessels and the background tissues. Because NIR light can penetrate deep into the brain tissues through the skin and skull, we are able to successfully reconstruct the vascular distribution in the rat brain from the photoacoustic signals. On the basis of differential optical absorption with and without contrast enhancement, a photoacoustic angiograph of a rat brain is acquired that matches the anatomical photograph well and exhibits high spatial resolution and a much-reduced background. This new technology demonstrates the potential for dynamic and molecular biomedical imaging.",
"doi": "10.1364/OL.29.000730",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2004-04-01",
"series_number": "7",
"volume": "29",
"issue": "7",
"pages": "730-732"
},
{
"id": "authors:0c0dc-6a011",
"collection": "authors",
"collection_id": "0c0dc-6a011",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161207-160158037",
"type": "article",
"title": "Reconstructions in limited-view thermoacoustic tomography",
"author": [
{
"family_name": "Xu",
"given_name": "Yuan",
"orcid": "0000-0001-9326-2197",
"clpid": "Xu-Yuan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Ambartsoumian",
"given_name": "Gaik",
"clpid": "Ambartsoumian-G"
},
{
"family_name": "Kuchment",
"given_name": "Peter",
"clpid": "Kuchment-P"
}
],
"abstract": "The limited-view problem is studied for thermoacoustic tomography, which is also referred to as photoacoustic or optoacoustic tomography depending on the type of radiation for the induction of acoustic waves. We define a \"detection region,\" within which all points have sufficient detection views. It is explained analytically and shown numerically that the boundaries of any objects inside this region can be recovered stably. Otherwise some sharp details become blurred. One can identify in advance the parts of the boundaries that will be affected if the detection view is insufficient. If the detector scans along a circle in a two-dimensional case, acquiring a sufficient view might require covering more than a \u03c0-, or less than a \u03c0-arc of the trajectory depending on the position of the object. Similar results hold in a three-dimensional case. In order to support our theoretical conclusions, three types of reconstruction methods are utilized: a filtered backprojection (FBP) approximate inversion, which is shown to work well for limited-view data, a local-tomography-type reconstruction that emphasizes sharp details (e.g., the boundaries of inclusions), and an iterative algebraic truncated conjugate gradient algorithm used in conjunction with FBP. Computations are conducted for both numerically simulated and experimental data. The reconstructions confirm our theoretical predictions.",
"doi": "10.1118/1.1644531",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2004-04",
"series_number": "4",
"volume": "31",
"issue": "4",
"pages": "724-733"
},
{
"id": "authors:hpaz0-wxd33",
"collection": "authors",
"collection_id": "hpaz0-wxd33",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170131-102649377",
"type": "article",
"title": "Ultrasound-modulated optical computed tomography of biological tissues",
"author": [
{
"family_name": "Li",
"given_name": "Jun",
"clpid": "Li-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "An optical imaging technique called ultrasound-modulated optical computed tomography is demonstrated for tomographic imaging of biological tissues. Ultrasound-modulated optical signals are extracted from scattered light to provide projection data for the image reconstruction. A filtered back-projection algorithm is implemented to reconstruct an image reflecting optical tissue properties from angular and linear scans of an ultrasonic beam across a sample. This reconstruction-based imaging technique provides a way to obtain images of cross sections containing the scanned ultrasonic axis in biological tissues, which enables three-dimensional ultrasound-modulated optical imaging. The technique combines the contrast advantage of optical waves and the resolution advantage of ultrasonic waves.",
"doi": "10.1063/1.1651330",
"issn": "0003-6951",
"publisher": "American Institute of Physics",
"publication": "Applied Physics Letters",
"publication_date": "2004-03-01",
"series_number": "9",
"volume": "84",
"issue": "9",
"pages": "1597-1599"
},
{
"id": "authors:3cf9f-cy452",
"collection": "authors",
"collection_id": "3cf9f-cy452",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160711-132025386",
"type": "article",
"title": "Signal dependence and noise source in ultrasound-modulated optical tomography",
"author": [
{
"family_name": "Yao",
"given_name": "Gang",
"clpid": "Yao-Gang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A Monte Carlo modeling technique was used to simulate ultrasound-modulated optical tomography in inhomogeneous scattering media. The contributions from two different modulation mechanisms were included in the simulation. Results indicate that ultrasound-modulated optical signals are much more sensitive to small embedded objects than unmodulated intensity signals. The differences between embedded absorption and scattering objects in the ultrasound-modulated optical signals were compared. The effects of neighboring inhomogeneity and background optical properties on the ultrasound-modulated optical signals were also studied. We analyzed the signal-to-noise ratio in the experiment and found that the major noise source is the speckle noise caused by small particle movement within the biological tissue sample. We studied this effect by incorporating a Brownian motion factor in the simulation.",
"doi": "10.1364/AO.43.001320",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2004-02-20",
"series_number": "6",
"volume": "43",
"issue": "6",
"pages": "1320-1326"
},
{
"id": "authors:p051q-0km97",
"collection": "authors",
"collection_id": "p051q-0km97",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160616-083045938",
"type": "article",
"title": "Time Reversal and Its Application to Tomography with Diffracting Sources",
"author": [
{
"family_name": "Xu",
"given_name": "Yuan",
"orcid": "0000-0001-9326-2197",
"clpid": "Xu-Yuan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "An exact time-domain method is proposed to time reverse a transient scalar wave using only the field measured on an arbitrary closed surface enclosing the initial source. Under certain conditions, a time-reversed field can be approximated by retransmitting the measured signals in a reversed temporal order. Exact reconstruction for three-dimensional broadband diffraction tomography (a linearized inverse scattering problem) is proposed by time-reversing the measured field back to the time when each secondary source is excited. The algorithm is verified by a numerical simulation. Extension to the case using Green's function in a heterogeneous medium is discussed.",
"doi": "10.1103/PhysRevLett.92.033902",
"issn": "0031-9007",
"publisher": "American Physical Society",
"publication": "Physical Review Letters",
"publication_date": "2004-01-23",
"series_number": "3",
"volume": "92",
"issue": "3",
"pages": "Art. No. 033902"
},
{
"id": "authors:3w7n5-k0k44",
"collection": "authors",
"collection_id": "3w7n5-k0k44",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-085059219",
"type": "article",
"title": "Ultrasound-Mediated Biophotonic Imaging: A Review of Acousto-Optical Tomography and Photo-Acoustic Tomography",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "This article reviews two types of ultrasound-mediated biophotonic imaging\u2013acousto-optical tomography (AOT, also called ultrasound-modulated optical tomography) and photo-acoustic tomography (PAT, also called opto-acoustic or thermo-acoustic tomography)\u2013both of which are based on non-ionizing optical and ultrasonic waves. The goal of these technologies is to combine the contrast advantage of the optical properties and the resolution advantage of ultrasound. In these two technologies, the imaging contrast is based primarily on the optical properties of biological tissues, and the imaging resolution is based primarily on the ultrasonic waves that either are provided externally or produced internally, within the biological tissues. In fact, ultrasonic mediation overcomes both the resolution disadvantage of pure optical imaging in thick tissues and the contrast and speckle disadvantages of pure ultrasonic imaging. In our discussion of AOT, the relationship between modulation depth and acoustic amplitude is clarified. Potential clinical applications of ultrasound-mediated biophotonic imaging include early cancer detection, functional imaging, and molecular imaging.",
"doi": "10.1155/2004/478079",
"pmcid": "PMC3851612",
"issn": "0278-0240",
"publisher": "Hindawi Publishing Corporation",
"publication": "Disease Markers",
"publication_date": "2004",
"series_number": "2-3",
"volume": "19",
"issue": "2-3",
"pages": "123-138"
},
{
"id": "authors:5nea1-rj480",
"collection": "authors",
"collection_id": "5nea1-rj480",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170131-110249709",
"type": "article",
"title": "Three-dimensional laser-induced photoacoustic tomography of mouse brain with the skin and skull intact",
"author": [
{
"family_name": "Wang",
"given_name": "Xueding",
"clpid": "Wang-Xueding"
},
{
"family_name": "Pang",
"given_name": "Yongjiang",
"clpid": "Pang-Yongjiang"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Three-dimensional laser-induced photoacoustic tomography, also referred to as optoacoustic tomography, is developed to image animal brain structures noninvasively with the skin and skull intact. This imaging modality combines the advantages of optical contrast and ultrasonic resolution. The distribution of optical absorption in a mouse brain is imaged successfully. The intrinsic optical contrast reveals not only blood vessels but also other detailed brain structures, such as the cerebellum, hippocampus, and ventriculi lateralis. The spatial resolution is primarily diffraction limited by the received photoacoustic waves. Imaged structures of the brain at different depths match the corresponding histological pictures well.",
"doi": "10.1364/OL.28.001739",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2003-10-01",
"series_number": "19",
"volume": "28",
"issue": "19",
"pages": "1739-1741"
},
{
"id": "authors:hx6e8-ekg72",
"collection": "authors",
"collection_id": "hx6e8-ekg72",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170131-105542212",
"type": "article",
"title": "Polarized light propagation through scattering media: time-resolved Monte Carlo simulations and experiments",
"author": [
{
"family_name": "Wang",
"given_name": "Xueding",
"clpid": "Wang-Xueding"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Sun",
"given_name": "Chia-Wei",
"clpid": "Sun-Chia-Wei"
},
{
"family_name": "Yang",
"given_name": "Chih-Chung",
"clpid": "Yang-Chih-Chung"
}
],
"abstract": "A study of polarized light transmitted through randomly scattering media of a polystyrene-microsphere solution is described. Temporal profiles of the Stokes vectors and the degree of polarization are measured experimentally and calculated theoretically based on a Monte Carlo technique. The experimental results match the theoretical results well, which demonstrates that the time-resolved Monte Carlo technique is a powerful tool that can contribute to the understanding of polarization propagation in biological tissue. Analysis based on the Stokes-Mueller formalism and the Mie theory shows that the first scattering event determines the major spatial patterns of the transmitted Stokes vectors. When an area detected at the output surface of a turbid medium is circularly symmetrical about the incident beam, the temporal profile of the transmitted light is independent of the incident polarization state. A linear relationship between the average order of the scatters and the light propagation time can be used to explain the exponential decay of the degree of polarization of transmitted light.",
"doi": "10.1117/1.1606462",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2003-10-01",
"series_number": "4",
"volume": "8",
"issue": "4",
"pages": "608-617"
},
{
"id": "authors:kxnmr-fqv17",
"collection": "authors",
"collection_id": "kxnmr-fqv17",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170131-103138593",
"type": "article",
"title": "Contrast mechanisms in polarization-sensitive Mueller-matrix optical coherence tomography and application in burn imaging",
"author": [
{
"family_name": "Jiao",
"given_name": "Shuliang",
"clpid": "Jiao-Shuliang"
},
{
"family_name": "Yu",
"given_name": "Wurong",
"clpid": "Yu-Wurong"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We investigate the various contrast mechanisms provided by polarization-sensitive (PS) Mueller-matrix optical coherence tomography (OCT). Our PS multichannel Mueller-matrix OCT is the first, to our knowledge, to offer simultaneously comprehensive polarization-contrast mechanisms, including the amplitude of birefringence, the orientation of birefringence, and the diattenuation in addition to the polarization-independent intensity contrast, all of which can be extracted from the measured Jones or the equivalent Mueller matrix. Theoretical analysis shows that when diattenuation is negligible, the round-trip Jones matrix represents a linear retarder, which is the foundation of conventional PS-OCT, and can be calculated with a single incident polarization state, although the one-way Jones matrix generally represents an elliptical retarder; otherwise, two incident polarization states are needed. The experimental results obtained from rat skin samples, which conform well with the histology, show that Mueller OCT provides complementary structural and functional information on biological samples and reveal that polarization contrast is more sensitive to thermal degeneration of biological tissue than amplitude-based contrast. Thus, Mueller OCT has significant potential for application in the noninvasive assessment of burn depth.",
"doi": "10.1364/AO.42.005191",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2003-09-01",
"series_number": "25",
"volume": "42",
"issue": "25",
"pages": "5191-5197"
},
{
"id": "authors:czx06-04837",
"collection": "authors",
"collection_id": "czx06-04837",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170131-141722751",
"type": "article",
"title": "Time-domain reconstruction algorithms and numerical simulations for thermoacoustic tomography in various geometries",
"author": [
{
"family_name": "Xu",
"given_name": "Minghua",
"clpid": "Xu-Minghua"
},
{
"family_name": "Xu",
"given_name": "Yuan",
"orcid": "0000-0001-9326-2197",
"clpid": "Xu-Yuan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In this paper, we present time-domain reconstruction algorithms for the thermoacoustic imaging of biological tissues. The algorithm for a spherical measurement configuration has recently been reported in another paper. Here, we extend the reconstruction algorithms to planar and cylindrical measurement configurations. First, we generalize the rigorous reconstruction formulas by employing Green's function technique. Then, in order to detect small (compared with the measurement geometry) but deeply buried objects, we can simplify the formulas when two practical conditions exist: 1) that the high-frequency components of the thermoacoustic signals contribute more to the spatial resolution than the low-frequency ones, and 2) that the detecting distances between the thermoacoustic sources and the detecting transducers are much greater than the wavelengths of the high-frequency thermoacoustic signals (i.e., those that are useful for imaging). The simplified formulas are computed with temporal back projections and coherent summations over spherical surfaces using certain spatial weighting factors. We refer to these reconstruction formulas as modified back projections. Numerical results are given to illustrate the validity of these algorithms.",
"doi": "10.1109/TBME.2003.816081",
"issn": "0018-9294",
"publisher": "IEEE",
"publication": "IEEE Transactions on Biomedical Engineering",
"publication_date": "2003-09",
"series_number": "9",
"volume": "50",
"issue": "9",
"pages": "1086-1099"
},
{
"id": "authors:1kzer-exr79",
"collection": "authors",
"collection_id": "1kzer-exr79",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170131-103633376",
"type": "article",
"title": "Effects of acoustic heterogeneity in breast thermoacoustic tomography",
"author": [
{
"family_name": "Xu",
"given_name": "Yuan",
"orcid": "0000-0001-9326-2197",
"clpid": "Xu-Yuan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The effects of wavefront distortions induced by acoustic heterogeneities in breast thermoacoustic tomography (TAT) are studied. Amplitude distortions are shown to be insignificant for different scales of acoustic heterogeneities. For wavelength-scale, or smaller, heterogeneities, amplitude distortion of the wavefront is minor as a result of diffraction when the detectors are placed in the far field of the heterogeneities. For larger-scale heterogeneities at the parenchyma wall, by using a ray approach (geometric optics), we show that no refraction-induced multipath interference occurs and, consequently, that no severe amplitude distortion, such as is found in ultrasound tomography, exists. Next, we consider the effects of phase distortions (errors in time-of-flight) in our numerical studies. The numerical results on the spreads of point sources and boundaries caused by the phase distortions are in good agreement with the proposed formula. After that, we demonstrate that the blurring of images can be compensated for by using the distribution of acoustic velocity in the tissues in the reconstructions. The effects of the errors in the acoustical velocities on this compensation also are investigated. An approach to implement the compensation using only TAT data is proposed. Lastly, the differences in the effects of acoustic heterogeneity and the generation of speckles in breast TAT and breast ultrasound imaging are discussed.",
"doi": "10.1109/TUFFC.2003.1235325",
"issn": "0885-3010",
"publisher": "IEEE",
"publication": "IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control",
"publication_date": "2003-09",
"series_number": "9",
"volume": "50",
"issue": "9",
"pages": "1134-1146"
},
{
"id": "authors:mh39b-x7e30",
"collection": "authors",
"collection_id": "mh39b-x7e30",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170131-104612458",
"type": "article",
"title": "Optical-fiber-based Mueller optical coherence tomography",
"author": [
{
"family_name": "Jiao",
"given_name": "Shuliang",
"clpid": "Jiao-Shuliang"
},
{
"family_name": "Yu",
"given_name": "Wurong",
"clpid": "Yu-Wurong"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "An optical-fiber-based multichannel polarization-sensitive Mueller optical coherence tomography (OCT) system was built to acquire the Jones or Mueller matrix of a scattering medium, such as biological tissue. For the first time to our knowledge, fiber-based polarization-sensitive OCT was dynamically calibrated to eliminate the polarization distortion caused by the single-mode optical fiber in the sample arm, thereby overcoming a key technical impediment to the application of optical fibers in this technology. The round-trip Jones matrix of the sampling fiber was acquired from the reflecting surface of the sample for each depth scan (A scan) with our OCT system. A new rigorous algorithm was then used to retrieve the calibrated polarization properties of the sample. This algorithm was validated with experimental data. The skin of a rat was imaged with this fiber-based system.",
"doi": "10.1364/OL.28.001206",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2003-07-15",
"series_number": "14",
"volume": "28",
"issue": "14",
"pages": "1206-1208"
},
{
"id": "authors:yycdx-xhh28",
"collection": "authors",
"collection_id": "yycdx-xhh28",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-084721718",
"type": "article",
"title": "Transmission- and side-detection configurations in ultrasound-modulated optical tomography of thick biological tissues",
"author": [
{
"family_name": "Li",
"given_name": "Jun",
"clpid": "Li-Jun"
},
{
"family_name": "Sakad\u017ei\u0107",
"given_name": "Sava",
"clpid": "Sakad\u017ei\u0107-S"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Ultrasound-modulated optical tomography of thick biological tissues was studied based on speckle-contrast detection. Speckle decorrelation was investigated with biological tissue samples of various thicknesses. Images of optically absorbing objects buried in biological tissue samples with thicknesses up to 50 mm were obtained in a transmission-detection configuration. The image contrast was more than 30%, and the spatial resolution was approximately 2 mm. In addition, a side-detection scheme along with two specific configurations were examined, and the advantages were demonstrated. Experimental results implied feasibility of applying the ultrasound-modulation technique to characterize optical properties in inhomogeneous biological tissues.",
"doi": "10.1364/AO.42.004088",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2003-07-01",
"series_number": "19",
"volume": "42",
"issue": "19",
"pages": "4088-4094"
},
{
"id": "authors:qy1p2-hhm46",
"collection": "authors",
"collection_id": "qy1p2-hhm46",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170314-134813209",
"type": "article",
"title": "Polarization reveals the details",
"author": [
{
"family_name": "Jiao",
"given_name": "Shuliang",
"clpid": "Jiao-Shuliang"
},
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Optical coherence tomography (OCT) is an interferometric, noninvasive, noncontact imaging technology that can image biological tissues at micrometer-scale resolutions. Since it was first developed in 1991, the technique has become a major area of research in the field of biomedical optics with applications in ophthalmology, cardiology, neurology, gynecology, dermatology, dentistry, developmental biology, urology, and gastroenterology.",
"doi": "10.1117/2.5200307.0002",
"issn": "1533-5496",
"publisher": "SPIE",
"publication": "OE Magazine",
"publication_date": "2003-07"
},
{
"id": "authors:ykahz-66n91",
"collection": "authors",
"collection_id": "ykahz-66n91",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160608-160149843",
"type": "article",
"title": "Noninvasive laser-induced photoacoustic tomography for structural and functional in vivo imaging of the brain",
"author": [
{
"family_name": "Wang",
"given_name": "Xueding",
"clpid": "Wang-Xueding"
},
{
"family_name": "Pang",
"given_name": "Yongjiang",
"clpid": "Pang-Yongjiang"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Xie",
"given_name": "Xueyi",
"clpid": "Xie-Xueyi"
},
{
"family_name": "Stoica",
"given_name": "George",
"orcid": "0000-0001-8071-4828",
"clpid": "Stoica-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Imaging techniques based on optical contrast analysis can be used to visualize dynamic and functional properties of the nervous system via optical signals resulting from changes in blood volume, oxygen consumption and cellular swelling associated with brain physiology and pathology. Here we report in vivo noninvasive transdermal and transcranial imaging of the structure and function of rat brains by means of laser-induced photoacoustic tomography (PAT). The advantage of PAT over pure optical imaging is that it retains intrinsic optical contrast characteristics while taking advantage of the diffraction-limited high spatial resolution of ultrasound. We accurately mapped rat brain structures, with and without lesions, and functional cerebral hemodynamic changes in cortical blood vessels around the whisker-barrel cortex in response to whisker stimulation. We also imaged hyperoxia- and hypoxia-induced cerebral hemodynamic changes. This neuroimaging modality holds promise for applications in neurophysiology, neuropathology and neurotherapy.",
"doi": "10.1038/nbt839",
"issn": "1087-0156",
"publisher": "Nature Publishing Group",
"publication": "Nature Biotechnology",
"publication_date": "2003-07",
"series_number": "7",
"volume": "21",
"issue": "7",
"pages": "803-806"
},
{
"id": "authors:mpz7t-5fv41",
"collection": "authors",
"collection_id": "mpz7t-5fv41",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160711-155756395",
"type": "article",
"title": "Analytic explanation of spatial resolution related to bandwidth and detector aperture size in thermoacoustic or photoacoustic reconstruction",
"author": [
{
"family_name": "Xu",
"given_name": "Minghua",
"clpid": "Xu-Minghua"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "An analytic explanation of the spatial resolution in thermoacoustic or photoacoustic reconstruction is presented. Three types of specific recording geometries, including spherical, planar, and cylindrical surface, as well as other general cases, are investigated. Analytic expressions of the point-spread functions (PSF's), as a function of the bandwidth of the measurement system and the finite size of the detector aperture, are derived based on rigorous reconstruction formulas. The analyses clearly reveal that the dependence of the PSF's on the bandwidth of all recording geometries shares the same space-invariant expression while the dependence on the aperture size of the detector differs. The bandwidth affects both axial and lateral resolutions; in contrast, the detector aperture blurs the lateral resolution greatly but the axial resolution only slightly.",
"doi": "10.1103/PhysRevE.67.056605",
"issn": "1063-651X",
"publisher": "American Physical Society",
"publication": "Physical Review E",
"publication_date": "2003-05",
"series_number": "5",
"volume": "67",
"issue": "5",
"pages": "Art. No. 056605"
},
{
"id": "authors:d2js1-x8j50",
"collection": "authors",
"collection_id": "d2js1-x8j50",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170131-105144286",
"type": "article",
"title": "Optimum pulse duration and radiant exposure for vascular laser therapy of dark port-wine skin: a theoretical study",
"author": [
{
"family_name": "Tunnell",
"given_name": "James W.",
"clpid": "Tunnell-J-W"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Anvari",
"given_name": "Bahman",
"clpid": "Anvari-B"
}
],
"abstract": "Laser therapy for cutaneous hypervascular malformations such as port-wine stain birthmarks is currently not feasible for dark-skinned individuals. We study the effects of pulse duration, radiant exposure, and cryogen spray cooling (CSC) on the thermal response of skin, using a Monte Carlo based optical-thermal model. Thermal injury to the epidermis decreases with increasing pulse duration during irradiation at a constant radiant exposure; however, maintaining vascular injury requires that the radiant exposure also increase. At short pulse durations, only a minimal increase in radiant exposure is necessary for a therapeutic effect to be achieved because thermal diffusion from the vessels is minimal. However, at longer pulse durations the radiant exposure must be greatly increased. There exists an optimum pulse duration at which minimal damage to the epidermis and significant injury within the targeted vasculature occur. For example, the model predicts optimum pulse durations of approximately 1.5, 6, and 20 ms for vessel diameters of 40, 80, and 120 \u03bcm, respectively. Optimization of laser pulse duration and radiant exposure in combination with CSC may offer a means to treat cutaneous lesions in dark-skinned individuals.",
"doi": "10.1364/AO.42.001367",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2003-03-01",
"series_number": "7",
"volume": "42",
"issue": "7",
"pages": "1367-1378"
},
{
"id": "authors:kn32k-cx067",
"collection": "authors",
"collection_id": "kn32k-cx067",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-134935888",
"type": "article",
"title": "Photoacoustic tomography of biological tissues with high cross-section resolution: Reconstruction and experiment",
"author": [
{
"family_name": "Wang",
"given_name": "Xueding",
"clpid": "Wang-Xueding"
},
{
"family_name": "Xu",
"given_name": "Yuan",
"orcid": "0000-0001-9326-2197",
"clpid": "Xu-Yuan"
},
{
"family_name": "Xu",
"given_name": "Minghua",
"clpid": "Xu-Minghua"
},
{
"family_name": "Yokoo",
"given_name": "Seiichirou",
"clpid": "Yokoo-Seiichirou"
},
{
"family_name": "Fry",
"given_name": "Edward S.",
"clpid": "Fry-E-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A modified back-projection approach deduced from an exact reconstruction solution was applied to our photoacoustic tomography of the optical absorption in biological tissues. Pulses from a Ti:sapphire laser (4.7 ns FWHM at 789.2 nm) were employed to generate a distribution of photoacoustic sources in a sample. The sources were detected by a wide-band nonfocused ultrasonic transducer at different positions around the imaging cross section perpendicular to the axis of the laser irradiation. Reconstructed images of phantoms made from chicken breast tissue agreed well with the structures of the samples. The resolution in the imaging cross section was experimentally demonstrated to be better than 60 \u03bcm when a 10 MHz transducer (140% bandwidth at \u221260 dB) was employed, which was nearly diffraction limited by the detectable photoacoustic waves of the highest frequency.",
"doi": "10.1118/1.1521720",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2002-12",
"series_number": "12",
"volume": "29",
"issue": "12",
"pages": "2799-2805"
},
{
"id": "authors:t683v-65653",
"collection": "authors",
"collection_id": "t683v-65653",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-092623874",
"type": "article",
"title": "Ultrasound-modulated optical tomography of biological tissue by use of contrast of laser speckles",
"author": [
{
"family_name": "Li",
"given_name": "Jun",
"clpid": "Li-Jun"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Ultrasound-modulated optical tomography based on the measurement of laser-speckle contrast was investigated. An ultrasonic beam was focused into a biological-tissue sample to modulate the laser light passing through the ultrasonic column inside the tissue. The contrast of the speckle pattern formed by the transmitted light was found to depend on the ultrasonic modulation and could be used for imaging. Variation in the speckle contrast reflected optical inhomogeneity in the tissue. With this technique, two-dimensional images of biological-tissue samples of as much as 25 mm thick were successfully obtained with a low-power laser. The technique was experimentally compared with speckle-contrast-based, purely optical imaging and with parallel-detection imaging techniques, and the advantages over each were demonstrated.",
"doi": "10.1364/AO.41.006030",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2002-10-01",
"series_number": "28",
"volume": "41",
"issue": "28",
"pages": "6030-6035"
},
{
"id": "authors:5z6n4-gxg83",
"collection": "authors",
"collection_id": "5z6n4-gxg83",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-104428351",
"type": "article",
"title": "Autocorrelation of scattered laser light for ultrasound-modulated optical tomography in dense turbid media",
"author": [
{
"family_name": "Li",
"given_name": "Hui",
"clpid": "Li-Hui"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Based on measurement of the intensity autocorrelation function, a new method to determine the modulation depth of scattered laser light modulated by an ultrasonic wave in turbid media was applied to ultrasound-modulated optical tomography. Good signal-to-noise ratios and high sensitivities were demonstrated. Images of double optically absorbing objects buried in a highly optically scattering gel sample were obtained. The contrast was more than 10%, and the spatial resolution was approximately 2 mm.",
"doi": "10.1364/AO.41.004739",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2002-08-01",
"series_number": "22",
"volume": "41",
"issue": "22",
"pages": "4739-4742"
},
{
"id": "authors:q7rb8-0qh29",
"collection": "authors",
"collection_id": "q7rb8-0qh29",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-140855040",
"type": "article",
"title": "Pulsed-microwave-induced thermoacoustic tomography: Filtered backprojection in a circular measurement configuration",
"author": [
{
"family_name": "Xu",
"given_name": "Minghua",
"clpid": "Xu-Minghua"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Our study on pulsed-microwave-induced thermoacoustic tomography in biological tissues is presented. A filtered backprojection algorithm based on rigorous theory is used to reconstruct the cross-sectional image from a thermoacoustic measurement in a circular configuration that encloses the sample under study. Specific details describing the measurement of thermoacoustic waves and the implementation of the reconstruction algorithm are discussed. A two-dimensional (2D) phantom sample with 2 mm features can be imaged faithfully. Through numerical simulation, the full width half-maximum (FWHM) of the point-spread function (PSF) is calculated to estimate the spatial resolution. The results demonstrate that the circular measurement configuration combined with the filtered backprojection method is a promising technique for detecting small tumors buried in biological tissues by utilizing microwave absorption contrast and ultrasound spatial resolution (\u223cmm).",
"doi": "10.1118/1.1493778",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2002-08",
"series_number": "8",
"volume": "29",
"issue": "8",
"pages": "1661-1669"
},
{
"id": "authors:3pe53-2b481",
"collection": "authors",
"collection_id": "3pe53-2b481",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-091544621",
"type": "article",
"title": "Ultrasonic modulation of multiply scattered coherent light: An analytical model for anisotropically scattering media",
"author": [
{
"family_name": "Sakad\u017ei\u0107",
"given_name": "Sava",
"clpid": "Sakad\u017ei\u0107-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "In this work, we have calculated analytically the temporal autocorrelation function of the electrical field component of multiply scattered coherent light transmitted through an anisotropically scattering media irradiated with a plane ultrasonic wave. The accuracy of the analytical solution is verified with an independent Monte Carlo simulation for different values of the ultrasonic and optical parameters. The analytical model shows that an approximate similarity relation exists; if the reduced scattering coefficient is unchanged regardless of the mean cosine of the scattering angle, the autocorrelation function remains approximately the same.",
"doi": "10.1103/PhysRevE.66.026603",
"issn": "1063-651X",
"publisher": "American Physical Society",
"publication": "Physical Review E",
"publication_date": "2002-08",
"series_number": "2",
"volume": "66",
"issue": "2",
"pages": "Art. No. 026603"
},
{
"id": "authors:8v257-hzp50",
"collection": "authors",
"collection_id": "8v257-hzp50",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-105428719",
"type": "article",
"title": "Degree of polarization in laser speckles from turbid media: Implications in tissue optics",
"author": [
{
"family_name": "Li",
"given_name": "Jun",
"clpid": "Li-Jun"
},
{
"family_name": "Yao",
"given_name": "Gang",
"clpid": "Yao-Gang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The degree of polarization (DOP) of laser-speckle fields, where the speckles were generated by a polarized laser beam incident upon two kinds of samples: ground glass and wax, was investigated within a single coherence area as well as over multiple coherence areas. For the surface-scattering ground glass, the incident polarization state was preserved in the speckle field, and hence the DOP remained at unity regardless of the area of detection. For the volume-scattering wax, the polarization states varied with positions in the field, and consequently the DOP depended on the area of detection: the DOP decreased with an increasing area of detection, and only when the area was much smaller than the coherence area would the DOP approach unity. A numerical simulation explained the experimental observation. These results are important for the understanding of polarization phenomena in turbid media such as biological tissue.",
"doi": "10.1117/1.1483313",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2002-07-01",
"series_number": "3",
"volume": "7",
"issue": "3",
"pages": "307-312"
},
{
"id": "authors:6gev6-k9w40",
"collection": "authors",
"collection_id": "6gev6-k9w40",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-125640928",
"type": "article",
"title": "Jones-matrix imaging of biological tissues with quadruple-channel optical coherence tomography",
"author": [
{
"family_name": "Jiao",
"given_name": "Shuliang",
"clpid": "Jiao-Shuliang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Two-dimensional depth-resolved Jones-matrix images of scattering biological tissues were measured with novel double-source double-detector polarization-sensitive optical coherence tomography (OCT). The Jones matrix can be determined in a single scan with this OCT system. The experimental results show that this system can be effectively applied to the measurement of soft tissues, which are less stable than hard tissues. Polarization parameters such as diattenuation, birefringence, and orientation of the fast axis can be extracted through decomposition of the measured Jones matrix. The Jones matrix of thermally treated porcine tendon showed a reduction of birefringence from thermal damage. The Jones matrices of porcine skin and bovine cartilage also revealed that the density and orientation of the collagen fibers in porcine skin and bovine cartilage are not distributed as uniformly as in porcine tendon. Birefringence is sensitive to changes in tissue because it is based on phase contrast.",
"doi": "10.1117/1.1483878",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2002-07-01",
"series_number": "3",
"volume": "7",
"issue": "3",
"pages": "350-358"
},
{
"id": "authors:fnrpz-ah467",
"collection": "authors",
"collection_id": "fnrpz-ah467",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-142444792",
"type": "article",
"title": "Special Section Guest Editorial - Tissue Polarimetry",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Cot\u00e9",
"given_name": "Gerard L.",
"clpid": "Cot\u00e9-G-L"
},
{
"family_name": "Jacques",
"given_name": "Steven L.",
"clpid": "Jacques-S-L"
}
],
"abstract": "Tissue polarimetry is an emerging area of technology development in tissue optics that is expected to lead to important research applications in biology and medicine. Traditional polarimetry is a mature field, but its application to thick tissues has been hindered by technical hurdles associated with multiple light scattering. However, light is intrinsically polarized; and many biological tissue components or molecules\u2014such as collagen, muscle fibers, keratin, retina, and glucose\u2014possess polarization properties. Further, biological scatterers\u2014such as cell nuclei and mitochondria\u2014alter light polarization upon each scattering event according to the geometric and optical parameters of the scatterers. Since incident polarized light is rapidly depolarized by scattering, polarization-sensitive detection of reflected or transmitted light selects only the early escaping photons and rejects multiply scattered light. Hence, polarized light offers a means of gating: reflected polarized photons interrogate superficial tissue layers, whereas transmitted polarized photons image the ballistic or quasi-ballistic region. Polarization can therefore provide novel contrast mechanisms for imaging, diagnosis, and sensing.",
"doi": "10.1117/1.1489434",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2002-07",
"series_number": "3",
"volume": "7",
"issue": "3",
"pages": "278"
},
{
"id": "authors:c4e5t-xf790",
"collection": "authors",
"collection_id": "c4e5t-xf790",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160614-100850177",
"type": "article",
"title": "Time-domain reconstruction for thermoacoustic tomography in a spherical geometry",
"author": [
{
"family_name": "Xu",
"given_name": "Minghua",
"clpid": "Xu-Minghua"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Reconstruction-based microwave-induced thermoacoustic tomography in a spherical configuration is presented. Thermoacoustic waves from biological tissue samples excited by microwave pulses are measured by a wide-band unfocused ultrasonic transducer, which is set on a spherical surface enclosing the sample. Sufficient data are acquired from different directions to reconstruct the microwave absorption distribution. An exact reconstruction solution is derived and approximated to a modified backprojection algorithm. Experiments demonstrate that the reconstructed images agree well with the original samples. The spatial resolution of the system reaches 0.5 mm.",
"doi": "10.1109/TMI.2002.801176",
"issn": "0278-0062",
"publisher": "IEEE",
"publication": "IEEE Transactions on Medical Imaging",
"publication_date": "2002-07",
"series_number": "7",
"volume": "21",
"issue": "7",
"pages": "814-822"
},
{
"id": "authors:peh6c-2h064",
"collection": "authors",
"collection_id": "peh6c-2h064",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-135334462",
"type": "article",
"title": "Propagation of polarized light in birefringent turbid media: A Monte Carlo study",
"author": [
{
"family_name": "Wang",
"given_name": "Xueding",
"clpid": "Wang-Xueding"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A detailed study, based on a Monte Carlo algorithm, of polarized light propagation in birefringent turbid media is presented in this paper. Linear birefringence, which results from the fibrous structures, changes the single scattering matrix and alters the polarization states of photons propagating in biological tissues. Some Mueller matrix elements of light backscattered from birefringent anisotropic turbid media present unusual intensity patterns compared with those for nonbirefringent isotropic turbid media. This result is in good agreement with the analytic results based on the double-scattering model. Degree of polarization, Stokes parameters, and diffuse reflectance as functions of linearly birefringent parameters based on numerical results and theoretical analysis are discussed and compared in an effort to understand the essential physical processes of polarized light propagation in fibrous tissues.",
"doi": "10.1117/1.1483315",
"issn": "1083-3668",
"publisher": "Society of Photo-Optical Instrumentation Engineers",
"publication": "Journal of Biomedical Optics",
"publication_date": "2002-07",
"series_number": "3",
"volume": "7",
"issue": "3",
"pages": "279-290"
},
{
"id": "authors:jvq32-r0531",
"collection": "authors",
"collection_id": "jvq32-r0531",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-111548259",
"type": "article",
"title": "Exact frequency-domain reconstruction for thermoacoustic tomography. II. Cylindrical geometry",
"author": [
{
"family_name": "Xu",
"given_name": "Yuan",
"orcid": "0000-0001-9326-2197",
"clpid": "Xu-Yuan"
},
{
"family_name": "Xu",
"given_name": "Minghua",
"clpid": "Xu-Minghua"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "For pt. I see ibid., vol. 21, no. 7, p. 823-8 (2002). Microwave-induced thermoacoustic tomography (TAT) in a cylindrical configuration is developed to image biological tissue. Thermoacoustic signals are acquired by scanning a flat ultrasonic transducer. Using a new expansion of a spherical wave in cylindrical coordinates, we apply the Fourier and Hankel transforms to TAT and obtain an exact frequency-domain reconstruction method. The effect of discrete spatial sampling on image quality is analyzed. An aliasing-proof reconstruction method is proposed. Numerical and experimental results are included.",
"doi": "10.1109/TMI.2002.801171",
"issn": "0278-0062",
"publisher": "IEEE",
"publication": "IEEE Transactions on Medical Imaging",
"publication_date": "2002-07",
"series_number": "7",
"volume": "21",
"issue": "7",
"pages": "829-833"
},
{
"id": "authors:31k09-tzf61",
"collection": "authors",
"collection_id": "31k09-tzf61",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-110149420",
"type": "article",
"title": "Exact frequency-domain reconstruction for thermoacoustic tomography. I. Planar geometry",
"author": [
{
"family_name": "Xu",
"given_name": "Yuan",
"orcid": "0000-0001-9326-2197",
"clpid": "Xu-Yuan"
},
{
"family_name": "Feng",
"given_name": "Dazi",
"clpid": "Feng-Dazi"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We report an exact and fast Fourier-domain reconstruction algorithm for thermoacoustic tomography in a planar configuration assuming thermal confinement and constant acoustic speed. The effects of the finite size of the detector and the finite length of the excitation pulse are explicitly included in the reconstruction algorithm. The algorithm is numerically and experimentally verified. We also demonstrate that the blurring caused by the finite size of the detector surface is the primary limiting factor on the resolution and that it can be compensated for by deconvolution.",
"doi": "10.1109/TMI.2002.801172",
"issn": "0278-0062",
"publisher": "IEEE",
"publication": "IEEE Transactions on Medical Imaging",
"publication_date": "2002-07",
"series_number": "7",
"volume": "21",
"issue": "7",
"pages": "823-828"
},
{
"id": "authors:abkaq-5mv32",
"collection": "authors",
"collection_id": "abkaq-5mv32",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-130915446",
"type": "article",
"title": "Methods for parallel-detection-based ultrasound-modulated optical tomography",
"author": [
{
"family_name": "Li",
"given_name": "Jun",
"clpid": "Li-Jun"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The research reported here focuses on ultrasound-modulated optical tomography based on parallel speckle detection. Four methods were investigated for signal acquisition and analysis, in which laser speckle statistics was applied. The methods were compared with the previously used four-phase method in the imaging of all-biological-tissue samples, in which the buried objects were also biological tissues. The image quality obtained with these methods was comparable with that obtained with the four-phase method; in addition, these methods have advantages in reducing acquisition time and improving the signal-to-noise ratio.",
"doi": "10.1364/AO.41.002079",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2002-04-01",
"series_number": "10",
"volume": "41",
"issue": "10",
"pages": "2079-2084"
},
{
"id": "authors:t0swv-c7608",
"collection": "authors",
"collection_id": "t0swv-c7608",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-132613947",
"type": "article",
"title": "Monte Carlo model and single-scattering approximation of the propagation of polarized light in turbid media containing glucose",
"author": [
{
"family_name": "Wang",
"given_name": "Xueding",
"clpid": "Wang-Xueding"
},
{
"family_name": "Yao",
"given_name": "Gang",
"clpid": "Yao-Gang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We present a single-scattering model as well as a Monte Carlo model of the effect of glucose on polarized light in turbid media. Glucose alters the Mueller-matrix patterns of diffusely backscattered and forward-scattered light because glucose molecules rotate the polarization plane of linearly polarized light. For example, the angles of rotation in Mueller-matrix elements S_(21) and S_(12) are linearly related to the concentration of glucose and increase with the source\u2013detector distance. In the nondiffusion regime, the two models agree well with each other. In the diffusion regime, the single-scattering model is invalid, but there still exists a linear relationship between the angles of rotation in the Mueller-matrix elements and the concentration of glucose, which is predicted by the Monte Carlo model.",
"doi": "10.1364/AO.41.000792",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2002-02-01",
"series_number": "4",
"volume": "41",
"issue": "4",
"pages": "792-801"
},
{
"id": "authors:ap1ef-nf083",
"collection": "authors",
"collection_id": "ap1ef-nf083",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-091101554",
"type": "article",
"title": "Two-dimensional depth-resolved Mueller matrix of biological tissue measured with double-beam polarization-sensitive optical coherence tomography",
"author": [
{
"family_name": "Jiao",
"given_name": "Shuliang",
"clpid": "Jiao-Shuliang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A double-beam polarization-sensitive system based on optical coherence tomography was built to measure the Mueller matrix of scattering biological tissue with high spatial resolution. The Jones matrix of a sample can be determined with a single scan and subsequently converted into an equivalent nondepolarizing Mueller matrix. As a result, the system can be used to measure the Mueller matrix of an unstable sample, such as soft tissue. The polarization parameters of a porcine tendon, including magnitude and orientation of birefringence and diattenuation, were extracted by decomposition of the measured Mueller matrix.",
"doi": "10.1364/OL.27.000101",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2002-01-15",
"series_number": "2",
"volume": "27",
"issue": "2",
"pages": "101-103"
},
{
"id": "authors:zxchn-hjq31",
"collection": "authors",
"collection_id": "zxchn-hjq31",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170201-141254869",
"type": "article",
"title": "Skin lesion classification using oblique-incidence diffuse reflectance spectroscopic imaging",
"author": [
{
"family_name": "Mehr\u00fcbeo\u011flu",
"given_name": "Mehr\u00fcbe",
"clpid": "Mehr\u00fcbeo\u011flu-M"
},
{
"family_name": "Kehtarnavaz",
"given_name": "Nasser",
"clpid": "Kehtarnavaz-N"
},
{
"family_name": "Marquez",
"given_name": "Guillermo",
"clpid": "Marquez-G"
},
{
"family_name": "Duvic",
"given_name": "Madeleine",
"clpid": "Duvic-M"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We discuss the use of a noninvasive in vivo optical technique, diffuse reflectance spectroscopic imaging with oblique incidence, to distinguish between benign and cancer-prone skin lesions. Various image features were examined to classify the images from lesions into benign and cancerous categories. Two groups of lesions were processed separately: Group 1 includes keratoses, warts versus carcinomas; and group 2 includes common nevi versus dysplastic nevi. A region search algorithm was developed to extract both one- and two-dimensional spectral information. A bootstrap-based Bayes classifier was used for classification. A computer-assisted tool was then devised to act as an electronic second opinion to the dermatologist. Our approach generated only one false-positive misclassification out of 23 cases collected for group 1 and two misclassifications out of 34 cases collected for group 2 under the worst estimation condition.",
"doi": "10.1364/AO.41.000182",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2002-01-01",
"series_number": "1",
"volume": "41",
"issue": "1",
"pages": "182-192"
},
{
"id": "authors:25xe5-vjx74",
"collection": "authors",
"collection_id": "25xe5-vjx74",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-125952256",
"type": "article",
"title": "Microwave-induced thermoacoustic tomography: Reconstruction by synthetic aperture",
"author": [
{
"family_name": "Feng",
"given_name": "Dazi",
"clpid": "Feng-Dazi"
},
{
"family_name": "Xu",
"given_name": "Yuan",
"orcid": "0000-0001-9326-2197",
"clpid": "Xu-Yuan"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have applied the synthetic-aperture method to linear-scanning microwave-induced thermoacoustic tomography in biological tissues. A nonfocused ultrasonic transducer was used to receive thermoacoustic signals, to which the delay-and-sum algorithm was applied for image reconstruction. We greatly improved the lateral resolution of images and acquired a clear view of the circular boundaries of buried cylindrical objects, which could not be obtained in conventional linear-scanning microwave-induced thermoacoustic tomography based on focused transducers. Two microwave sources, which had frequencies of 9 and 3 GHz, respectively, were used in the experiments for comparison. The 3 GHz system had a much larger imaging depth but a lower signal\u2013noise ratio than the 9 GHz system in near-surface imaging.",
"doi": "10.1118/1.1418015",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2001-12",
"series_number": "12",
"volume": "28",
"issue": "12",
"pages": "2427-2431"
},
{
"id": "authors:n3762-k6t05",
"collection": "authors",
"collection_id": "n3762-k6t05",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-133103633",
"type": "article",
"title": "On the horizontal-well pumping tests in anisotropic confined aquifers",
"author": [
{
"family_name": "Zhan",
"given_name": "Hongbin",
"clpid": "Zhan-Hongbin"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Park",
"given_name": "Eungyu",
"clpid": "Park-Eungyu"
}
],
"abstract": "A method that directly solves the boundary problem of flow to a horizontal-well in an anisotropic confined aquifer is provided. This method solves the point source problem first, and then integrates the point source solution along the horizontal well axis to obtain the horizontal well solution. The short and long time approximations of drawdowns are discussed and are utilized in the semilog analysis of the drawdown. A closed-form analytical solution of geometrical skin effect at the wellbore is derived. Type curves and derivative type curves of horizontal pumping wells are generated using the chow program. This program also calculates the drawdown at any given observation well at any given time. The horizontal-well type curves are different from the vertical-well type curves at early time, reflecting the different nature of flow to a horizontal-well and to a vertical-well. The horizontal-well type curves converge to the vertical-well type curves at late time, showing the similar nature of flow to a horizontal-well and to a vertical-well at late time. The sensitivity of the type curves and derivative type curves on monitoring well location, aquifer anisotropy, horizontal well depth, and horizontal well length is tested. These type curves and derivative type curves can be used in the matching point method for interpreting the pumping test data.",
"doi": "10.1016/S0022-1694(01)00453-X",
"issn": "0022-1694",
"publisher": "Elsevier",
"publication": "Journal of Hydrology",
"publication_date": "2001-10-31",
"series_number": "1-4",
"volume": "252",
"issue": "1-4",
"pages": "37-50"
},
{
"id": "authors:yje3r-wez91",
"collection": "authors",
"collection_id": "yje3r-wez91",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-111054770",
"type": "article",
"title": "Microwave-induced thermoacoustic tomography using multi-sector scanning",
"author": [
{
"family_name": "Xu",
"given_name": "Minghua",
"clpid": "Xu-Minghua"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A study of microwave-induced thermoacoustic tomography of inhomogeneous tissues using multi-sector scanning is presented. A short-pulsed microwave beam is used to irradiate the tissue samples. The microwave absorption excites time-resolved acoustic waves by thermoelastic expansion. The amplitudes of the acoustic waves are strongly related to locally absorbed microwave-energy density. The acoustic waves may propagate in all spatial directions. A focused ultrasonic transducer is employed to acquire temporal acoustic signals from multiple directions. Each detected signal is converted into a one-dimensional (1D) image along the acoustic axis of the transducer. The cross-sectional images of the tissue samples are calculated by combining all of the 1D images acquired in the same planes.",
"doi": "10.1118/1.1395037",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2001-09",
"series_number": "9",
"volume": "28",
"issue": "9",
"pages": "1958-1963"
},
{
"id": "authors:462kg-99k22",
"collection": "authors",
"collection_id": "462kg-99k22",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-134536940",
"type": "article",
"title": "Propagation of polarized light in birefringent turbid media: time-resolved simulations",
"author": [
{
"family_name": "Wang",
"given_name": "Xueding",
"clpid": "Wang-Xueding"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A Monte Carlo model was used to analyze the propagation of polarized light in linearly birefringent turbid media, such as fibrous tissues. Linearly and circularly polarized light sources were used to demonstrate the change of polarizations in turbid media with different birefringent parameters. Videos of spatially distributed polarization states of light backscattered from or propagating in birefringent media are presented.",
"doi": "10.1364/OE.9.000254",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "2001-08-27",
"series_number": "5",
"volume": "9",
"issue": "5",
"pages": "254-259"
},
{
"id": "authors:w0z6y-ksk95",
"collection": "authors",
"collection_id": "w0z6y-ksk95",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-095440346",
"type": "article",
"title": "Mechanisms of ultrasonic modulation of multiply scattered coherent light: a Monte Carlo model",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A Monte Carlo model of the ultrasonic modulation of multiply scattered coherent light in scattering media is provided. The model is based on two mechanisms:\u2003the ultrasonic modulation of the index of refraction, which causes a modulation of the optical path lengths between consecutive scattering events, and the ultrasonic modulation of the displacements of scatterers, which causes a modulation of optical path lengths with each scattering event. Multiply scattered light accumulates modulated optical path lengths along its path. Consequently, the intensity of the speckles that are formed by the multiply scattered light is modulated. The contribution from the index of refraction is comparable with the contribution from displacement when the acoustic-wave vector is less than a critical fraction of the transport mean free path and becomes increasingly greater than the contribution from displacement beyond this critical point. This Monte Carlo model agrees well with an independent analytical model for isotropically scattering media. Both mechanisms are coherent phenomena, requiring the use of a coherent light source.",
"doi": "10.1364/OL.26.001191",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2001-08-01",
"series_number": "15",
"volume": "26",
"issue": "15",
"pages": "1191-1193"
},
{
"id": "authors:rd7bf-dcn40",
"collection": "authors",
"collection_id": "rd7bf-dcn40",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160617-094806907",
"type": "article",
"title": "Mechanisms of Ultrasonic Modulation of Multiply Scattered Coherent Light: An Analytic Model",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "An analytic model of the ultrasonic modulation of multiply scattered coherent light in scattering media is developed based on two mechanisms: the ultrasonic modulation of the index of refraction and the ultrasonic modulation of the displacements of Rayleigh scatterers. In water solutions, for example, the first mechanism is slightly less important than the second mechanism when the scattering mean free path is less than a critical fraction (0.0890) of the acoustic wavelength, and it becomes increasingly more important beyond this point. This model agrees well with an independent Monte Carlo model.",
"doi": "10.1103/PhysRevLett.87.043903",
"issn": "0031-9007",
"publisher": "American Physical Society",
"publication": "Physical Review Letters",
"publication_date": "2001-07-23",
"series_number": "4",
"volume": "87",
"issue": "4",
"pages": "Art. No. 043903"
},
{
"id": "authors:9ayan-9ym21",
"collection": "authors",
"collection_id": "9ayan-9ym21",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-140443612",
"type": "article",
"title": "Signal processing in scanning thermoacoustic tomography in biological tissues",
"author": [
{
"family_name": "Xu",
"given_name": "Yuan",
"orcid": "0000-0001-9326-2197",
"clpid": "Xu-Yuan"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Microwave-induced thermoacoustic tomography was explored to image biological tissues. Short microwave pulses irradiated tissues to generate acoustic waves by thermoelastic expansion. The microwave-induced thermoacoustic waves were detected with a focused ultrasonic transducer to obtain two-dimensional tomographic images of biological tissues. The dependence of the axial and the lateral resolutions on the spectra of the signals was studied. A reshaping filter was applied to the temporal piezoelectric signals from the transducer to increase the weight of the high-frequency components, which improved the lateral resolution, and to broaden the spectrum of the signal, which enhanced the axial resolution. A numerical simulation validated our signal-processing approach.",
"doi": "10.1118/1.1380436",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2001-07",
"series_number": "7",
"volume": "28",
"issue": "7",
"pages": "1519-1524"
},
{
"id": "authors:8q75g-nt957",
"collection": "authors",
"collection_id": "8q75g-nt957",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-133552771",
"type": "article",
"title": "Optical-thermal simulation of tonsillar tissue irradiation",
"author": [
{
"family_name": "Shah",
"given_name": "Rahul K.",
"clpid": "Shah-R-K"
},
{
"family_name": "Nemati",
"given_name": "Babak",
"clpid": "Nemati-B"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Shapshay",
"given_name": "Stanley M.",
"clpid": "Shapshay-S-M"
}
],
"abstract": "Background and Objective:\n\nDespite laser applications targetted toward tonsillar tissue, there has been no characterization of underlying optical and thermal events during laser irradiation of tonsillar tissue.\n\n\nStudy Design/Materials and Methods:\n\nThe optical properties of canine and human tonsils were determined at 805 nm (diode laser) and 1,064 nm (Nd:YAG laser). An optical-thermal simulation was developed to predict the temperature rise in irradiated human tonsils.\n\n\nResults:\n\nThe optical properties of human and canine tonsillar tissue are similar at both wavelengths. The optical-thermal simulation was validated and predicts that at 10 W and 1 minute of irradiation, the heat will be contained within the human tonsil. The diode laser causes more superficial heating than the Nd:YAG laser.\n\n\nConclusions:\n\nThe safety of irradiating human tonsils was shown. The diode laser is superior to the Nd:YAG laser because less heat affects collateral structures. The optical-thermal simulation detailed in this study can be used to predict the temperature rise in tissues undergoing irradiation.",
"doi": "10.1002/lsm.1055",
"issn": "0196-8092",
"publisher": "Wiley",
"publication": "Lasers in Surgery and Medicine",
"publication_date": "2001-04",
"series_number": "4",
"volume": "28",
"issue": "4",
"pages": "313-319"
},
{
"id": "authors:scg7s-q0627",
"collection": "authors",
"collection_id": "scg7s-q0627",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-135907488",
"type": "article",
"title": "Scanning microwave-induced thermoacoustic tomography: Signal, resolution, and contrast",
"author": [
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Scanning thermoacoustic tomography was explored in the microwave region of the electromagnetic spectrum. Short microwave pulses were used to induce acoustic waves by thermoelastic expansion in biological tissues. Cross sections of tissue samples were imaged by a linear scan of the samples while a focused ultrasonic transducer detected the time-resolved thermoacoustic signals. Based on the microwave-absorption properties of normal and cancerous breast tissues, the piezoelectric signals in response to the thermoacoustic contrast were investigated over a wide range of electromagnetic frequencies and depths of tumor locations. The axial resolution is related to the temporal profile of the microwave pulses and to the impulse response of the ultrasonic transducer. The lateral resolution is related to the numerical aperture of the ultrasonic transducer as well as to the frequency spectra of the piezoelectric signals in the time window corresponding to the axial resolution. Gain compensation, counteracting the microwave attenuation, was applied to enhance the image contrast.",
"doi": "10.1118/1.1333409",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2001-01",
"series_number": "1",
"volume": "28",
"issue": "1",
"pages": "4-10"
},
{
"id": "authors:93yx1-nw995",
"collection": "authors",
"collection_id": "93yx1-nw995",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-142949931",
"type": "article",
"title": "Depth-resolved two-dimensional Stokes vectors of backscattered light and Mueller matrices of biological tissue measured with optical coherence tomography",
"author": [
{
"family_name": "Jiao",
"given_name": "Shuliang",
"clpid": "Jiao-Shuliang"
},
{
"family_name": "Yao",
"given_name": "Gang",
"clpid": "Yao-Gang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Mueller matrices provide a complete characterization of the optical polarization properties of biological tissue. A polarization-sensitive optical coherence tomography (OCT) system was built and used to investigate the optical polarization properties of biological tissues and other turbid media. The apparent degree of polarization (DOP) of the backscattered light was measured with both liquid and solid scattering samples. The DOP maintains the value of unity within the detectable depth for the solid sample, whereas the DOP decreases with the optical depth for the liquid sample. Two-dimensional depth-resolved images of both the Stokes vectors of the backscattered light and the full Mueller matrices of biological tissue were measured with this system. These polarization measurements revealed some tissue structures that are not perceptible with standard OCT.",
"doi": "10.1364/AO.39.006318",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2000-12-01",
"series_number": "34",
"volume": "39",
"issue": "34",
"pages": "6318-6324"
},
{
"id": "authors:twtgx-9fw31",
"collection": "authors",
"collection_id": "twtgx-9fw31",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-145349723",
"type": "article",
"title": "Propagation of polarized light in turbid media: simulated animation sequences",
"author": [
{
"family_name": "Yao",
"given_name": "Gang",
"clpid": "Yao-Gang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A time-resolved Monte Carlo technique was used to simulate the propagation of polarized light in turbid media. Calculated quantities include the reflection Mueller matrices, the transmission Mueller matrices, and the degree of polarization (DOP). The effects of the polarization state of the incident light and of the size of scatterers on the propagation of DOP were studied. Results are shown in animation sequences.",
"doi": "10.1364/OE.7.000198",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "2000-08-28",
"series_number": "5",
"volume": "7",
"issue": "5",
"pages": "198-203"
},
{
"id": "authors:xqzhg-q2b33",
"collection": "authors",
"collection_id": "xqzhg-q2b33",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-143419144",
"type": "article",
"title": "Frequency-swept ultrasound-modulated optical tomography in biological tissue by use of parallel detection",
"author": [
{
"family_name": "Yao",
"given_name": "Gang",
"clpid": "Yao-Gang"
},
{
"family_name": "Jiao",
"given_name": "Shuliang",
"clpid": "Jiao-Shuliang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A frequency-swept ultrasonic beam was focused into a biological tissue sample to modulate the laser light passing through the ultrasonic beam inside the tissue. Parallel detection of the speckle field formed by the transmitted laser light was implemented with the source-synchronous-illumination lock-in technique to improve the signal-to-noise ratio. The ultrasound-modulated laser light reflects the local optical and mechanical properties in the ultrasonic beam and can be used for tomographic imaging of the tissue. Sweeping the ultrasonic frequency provides spatial resolution along the ultrasonic axis, which is scalable with the frequency span of the sweep. Two-dimensional images of biological tissue with buried objects were successfully obtained experimentally.",
"doi": "10.1364/OL.25.000734",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "2000-05-15",
"series_number": "10",
"volume": "25",
"issue": "10",
"pages": "734-736"
},
{
"id": "authors:2c31g-q6g49",
"collection": "authors",
"collection_id": "2c31g-q6g49",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-152231282",
"type": "article",
"title": "Scanning thermoacoustic tomography in biological tissue",
"author": [
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Microwave-induced thermoacoustic tomography was explored to image biological tissue. Short microwave pulses irradiated tissue to generate acoustic waves by thermoelastic expansion. The microwave-induced thermoacoustic waves were detected with a focused ultrasonic transducer. Each time-domain signal from the ultrasonic transducer represented a one-dimensional image along the acoustic axis of the ultrasonic transducer similar to an ultrasonic A-scan. Scanning the system perpendicularly to the acoustic axis of the ultrasonic transducer would generate multi-dimensional images. Two-dimensional tomographic images of biological tissue were obtained with 3-GHz microwaves. The axial and lateral resolutions were characterized. The time-domain piezo-electric signal from the ultrasonic transducer in response to the thermoacoustic signal was simulated theoretically, and the theoretical result agreed with the experimental result very well.",
"doi": "10.1118/1.598984",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "2000-05",
"series_number": "5",
"volume": "27",
"issue": "5",
"pages": "1195-1202"
},
{
"id": "authors:9bsha-hp256",
"collection": "authors",
"collection_id": "9bsha-hp256",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160720-130003261",
"type": "article",
"title": "Source of error in calculation of optical diffuse reflectance from turbid media using diffusion theory",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Jacques",
"given_name": "Steven L.",
"clpid": "Jacques-S-L"
}
],
"abstract": "Diffusion theory and similarity relations were used to calculate the optical diffuse reflectance of an infinitely narrow laser beam incident upon a semi-infinite turbid medium. The results were analyzed by comparison with the accurate results from Monte Carlo simulations. Because a large number of photon packets were traced, the variance of the results from Monte Carlo simulations was small enough to reveal the detailed defects of the diffusion theory and the similarity relations, which are broadly used in photomedicine. We demonstrated that both diffusion theory and similarity relations provide very accurate results when the photon sources are isotropic and buried more deeply than one transport mean free path in turbid media. We found that the key factor affecting the accuracy of the diffusion theory application was the conversion from the infinitely narrow laser beam to an isotropic point source in turbid media.",
"doi": "10.1016/S0169-2607(99)00041-3",
"issn": "0169-2607",
"publisher": "Elsevier",
"publication": "Computer Methods and Programs in Biomedicine",
"publication_date": "2000-03",
"series_number": "3",
"volume": "61",
"issue": "3",
"pages": "163-170"
},
{
"id": "authors:t0e3v-6pv55",
"collection": "authors",
"collection_id": "t0e3v-6pv55",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-152520639",
"type": "article",
"title": "Theoretical and experimental studies of ultrasound-modulated optical tomography in biological tissue",
"author": [
{
"family_name": "Yao",
"given_name": "Gang",
"clpid": "Yao-Gang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Ultrasound-modulated optical tomography in biological tissue was studied both theoretically and experimentally. An ultrasonic beam was focused into biological tissue samples to modulate the laser light passing through the ultrasonic beam inside the tissue. The ultrasound-modulated laser light reflects the local optical and mechanical properties in the ultrasonic beam and permits tomographic imaging of biological tissues by scanning. Parallel detection of the speckle field formed by the transmitted laser light was implemented with the source-synchronous-illumination lock-in technique to improve the signal-to-noise ratio. Two-dimensional images of biological tissues were successfully obtained experimentally with a laser beam at either normal or oblique incidence, which showed that ultrasound-modulated optical tomography depends on diffuse light rather than on ballistic light. Monte Carlo simulations showed that the modulation depth decreased much more slowly than the diffuse transmittance, which indicated the possibility that even thicker biological tissues can be imaged with this technique.",
"doi": "10.1364/AO.39.000659",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "2000-02-01",
"series_number": "4",
"volume": "39",
"issue": "4",
"pages": "659-664"
},
{
"id": "authors:82z6j-g8958",
"collection": "authors",
"collection_id": "82z6j-g8958",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-144928894",
"type": "article",
"title": "Optical-thermal simulation of human tonsillar tissue irradiation: Clinical implications",
"author": [
{
"family_name": "Shah",
"given_name": "Rahul K.",
"clpid": "Shah-R-K"
},
{
"family_name": "Nemati",
"given_name": "Babak",
"clpid": "Nemati-B"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Volk",
"given_name": "Mark S.",
"clpid": "Volk-M-S"
},
{
"family_name": "Shapshay",
"given_name": "Stanley M.",
"clpid": "Shapshay-S-M"
}
],
"abstract": "Background and Objective:\n\nMucosa intact laser tonsillar ablation is an alternative to conventional tonsillectomy. The efficacy of this procedure was demonstrated in canines, but establishing the safety of irradiating human tonsils is paramount.\n\nStudy Design/Materials and Methods:\n\nAn optical-thermal simulation of tonsillar tissue irradiation was previously developed, but the effect of varying parameters was not investigated. The tissue response to irradiation at 5\u201325 watts for 1 minute and 10 watts for 10 seconds to 162 seconds is simulated.\n\nResults:\n\nAt 15 watts and greater, the peak temperature is over 100\u00b0C and the mucosal temperature is over 70\u00b0C. At the depth of the tonsil, the temperature does not vary significantly. The peak temperature is at 1 mm. The radial temperature profile is not significantly altered by longer irradiation times.\n\nConclusions:\n\nThe optimal dosimetry parameters for irradiation of human tonsillar tissue at 805 nm with the MILTA technique is under 15 watts for approximately 1 minute.",
"doi": "10.1002/1096-9101(2000)27:3<269::AID-LSM9>3.0.CO;2-2",
"issn": "0196-8092",
"publisher": "Wiley",
"publication": "Lasers in Surgery and Medicine",
"publication_date": "2000",
"series_number": "3",
"volume": "27",
"issue": "3",
"pages": "269-273"
},
{
"id": "authors:wnteb-g9738",
"collection": "authors",
"collection_id": "wnteb-g9738",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-153206043",
"type": "article",
"title": "Cu K-Edge Studies of the Charge Carries in Th-Doped Cuprate System R_(2-x)Th_xCuO_(4-\u03b4) (R = Nd, Sm amd Gd)",
"author": [
{
"family_name": "Liang",
"given_name": "G.",
"clpid": "Liang-G"
},
{
"family_name": "Yi",
"given_name": "Y.",
"clpid": "Yi-Y"
},
{
"family_name": "Jardim",
"given_name": "R. F.",
"clpid": "Jardim-R-F"
},
{
"family_name": "Wang",
"given_name": "L. V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "To further study the charge carrier concentration in electron doped cuprate superconductors, a systematic x-ray absorption near edge structure (XANES) measurement has been carried out on Th-doped superconductor system R_(2-x)Th_xCuO_(4-\u03b4) (R=Nd, Sm, and Gd). The XANES results show that, similar to the Ce-doped compounds, while the intensity of the Cu^(1+)4p\u03c0 feature increase with the increase of the Th doping level x, the intensities of the Cu2+4p\u03c0 and 4p\u03c3 features decreases. This clearly indicates that the electrons doped by the Th atoms are injected into the local Cu 3d-orbitals. The normalized Cu^(1+)4p\u03c0 intensity data show that the Cu^(1+) concentration in the Th-doped compound series with different R-elements is linearly proportional to the Th doping-level x. The data suggest that both Ce and Th donate the same fraction of electrons into the Cu sites.",
"doi": "10.1142/S0217979299003854",
"issn": "0217-9792",
"publisher": "World Scientific Publishing",
"publication": "International Journal of Modern Physics B",
"publication_date": "1999-12-20",
"series_number": "29-31",
"volume": "13",
"issue": "29-31",
"pages": "3750-3754"
},
{
"id": "authors:v4hw7-dvk82",
"collection": "authors",
"collection_id": "v4hw7-dvk82",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170314-103202121",
"type": "article",
"title": "XANES Study of the Valence of Pb IN (Tl_(0.5)Pb_(0.5))Sr_2Ca_(1-x)Y_xCu_2O_(7- \u03b4)",
"author": [
{
"family_name": "Liang",
"given_name": "G.",
"clpid": "Liang-G"
},
{
"family_name": "Liu",
"given_name": "R. S.",
"clpid": "Liu-R-S"
},
{
"family_name": "Wang",
"given_name": "L. V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Near edge x-ray-absorption spectra at Pb L_3-edges have been measured for (Tl_(0.5)Pb_(0.5))Sr_2Ca_(1-x)Y_xCu_2O_(7-\u03b4) compound series. It is found that the intensity of the 2p\u21926s transition feature decreases with the substitution of Ca^(+2) by Y^(+3). This result indicates that some electronic charges have been transferred into the Pb(Tl)-O layers by this substitution. Detailed analysis suggests that the valence value of Pb in this compound series is close to +4 and it decreases with the increase of the Y-doping level x.",
"doi": "10.1142/S0217979299003684",
"issn": "0217-9792",
"publisher": "World Scientific Publishing",
"publication": "International Journal of Modern Physics B",
"publication_date": "1999-12-20",
"series_number": "29",
"volume": "13",
"issue": "29",
"pages": "3693-3696"
},
{
"id": "authors:1sqqq-arb97",
"collection": "authors",
"collection_id": "1sqqq-arb97",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170308-111604955",
"type": "article",
"title": "Full-field mapping of ultrasonic field by light-source-synchronized projection",
"author": [
{
"family_name": "Yao",
"given_name": "Gang",
"clpid": "Yao-Gang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "A simple method for imaging ultrasonic fields in clear media is introduced. A modulated laser source is used to project the ultrasonic field onto a CCD camera. By use of the source-synchronized lock-in detection scheme, 2D images of the amplitude and phase distributions can be determined simultaneously. This technique is experimentally demonstrated with a 1-MHz and a 3.5-MHz ultrasonic transducer operated in continuous-wave mode. This method is very straightforward to implement and can be combined with the traditional tomographic reconstruction technique to obtain the 3D distribution of an ultrasonic field.",
"doi": "10.1121/1.427892",
"issn": "0001-4966",
"publisher": "Acoustical Society of America",
"publication": "Journal of the Acoustical Society of America",
"publication_date": "1999-10",
"series_number": "4",
"volume": "106",
"issue": "4",
"pages": "L36-L40"
},
{
"id": "authors:59sc3-y0k80",
"collection": "authors",
"collection_id": "59sc3-y0k80",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170308-135750465",
"type": "article",
"title": "Monte Carlo simulation of an optical coherence tomography signal in homogeneous turbid media",
"author": [
{
"family_name": "Yao",
"given_name": "Gang",
"clpid": "Yao-Gang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "The Monte Carlo technique with angle biasing is used to simulate the optical coherence tomography (OCT) signal from homogeneous turbid media. The OCT signal is divided into two categories: one is from a target imaging layer in the medium (Class I); the other is from the rest of the medium (Class II). These two classes of signal are very different in their spatial distributions, angular distributions and the numbers of experienced scattering events. Multiply scattered light contributes to the Class I signal as well as the Class II signal. The average number of scattering events increases linearly with the probing depth. The Class II signal decays much more slowly than the Class I signal whose decay constant is close to the total attenuation coefficient of the turbid medium. The effect of the optical properties of the medium on the Class I signal decay is studied.",
"doi": "10.1088/0031-9155/44/9/316",
"issn": "0031-9155",
"publisher": "IOP",
"publication": "Physics in Medicine and Biology",
"publication_date": "1999-09",
"series_number": "9",
"volume": "44",
"issue": "9",
"pages": "2307-2320"
},
{
"id": "authors:d32dt-94k95",
"collection": "authors",
"collection_id": "d32dt-94k95",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170308-133716543",
"type": "article",
"title": "Microwave-induced acoustic imaging of biological tissues",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Zhao",
"given_name": "Xuemei",
"clpid": "Zhao-Xuemei"
},
{
"family_name": "Sun",
"given_name": "Haitao",
"clpid": "Sun-Haitao"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
}
],
"abstract": "We present tomographic imaging of biological tissues by use of microwave-induced acoustic signal. It was demonstrated that the acoustic signal was proportional to the intensity of the incident microwave and was related to the absorption property of microwave in the medium. Pulsed microwave radiation was used to illuminate the samples. Absorbed microwave energy caused thermoelastic expansion that radiated acoustic waves. A focused ultrasonic transducer detected the time-resolved acoustic signals. Each acoustic signal was converted into a one-dimensional image. A linear scanning of the ultrasonic transducer yielded multiple one-dimensional images, which formed a two-dimensional image. The imaging contrast is based on the difference in the dielectric constants among biological tissues. Because of the large contrast in microwave absorption among different tissue types, microwave-induced acoustic tomography could potentially provide a new modality for detecting early-stage cancers.",
"doi": "10.1063/1.1149986",
"issn": "0034-6748",
"publisher": "American Institute of Physics",
"publication": "Review of Scientific Instruments",
"publication_date": "1999-09",
"series_number": "9",
"volume": "70",
"issue": "9",
"pages": "3744-3748"
},
{
"id": "authors:4gam9-64e53",
"collection": "authors",
"collection_id": "4gam9-64e53",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-152838438",
"type": "article",
"title": "Absorption distribution of an optical beam focused into a turbid medium",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Liang",
"given_name": "Gan",
"clpid": "Liang-Gan"
}
],
"abstract": "The focusing of light into a turbid medium was studied with Monte Carlo simulations. Focusing was found to have a significant effect on the absorption distribution in turbid media when the depth of the focal point (the distance between the focal point and the surface of the turbid media) was less than or comparable with the transport mean free path. Focusing could significantly increase the peak absorption and narrow the absorption distribution. As the depth of the focal point increased, the peak absorption decreased, and the depth of peak absorption increased initially but quickly reached a plateau that was less than the transport mean free path. A refractive-index-mismatched boundary between the ambient medium and the turbid medium deteriorated the focusing effect, increased the absorption near the boundary, lowered the peak absorption, and broadened the absorption distribution.",
"doi": "10.1364/AO.38.004951",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "1999-08-01",
"series_number": "22",
"volume": "38",
"issue": "22",
"pages": "4951-4958"
},
{
"id": "authors:p4p23-6zw49",
"collection": "authors",
"collection_id": "p4p23-6zw49",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170308-133109525",
"type": "article",
"title": "Light backscattering polarization patterns from turbid media: theory and experiment",
"author": [
{
"family_name": "Rakovi\u0107",
"given_name": "Milun J.",
"clpid": "Rakovi\u0107-M-J"
},
{
"family_name": "Kattawar",
"given_name": "George W.",
"clpid": "Kattawar-G-W"
},
{
"family_name": "Mehr\u00fcbeo\u011flu",
"given_name": "Mehr\u00fcbe",
"clpid": "Mehr\u00fcbeo\u011flu-M"
},
{
"family_name": "Cameron",
"given_name": "Brent D.",
"clpid": "Cameron-B-D"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Rastegar",
"given_name": "Sohi",
"clpid": "Rastegar-S"
},
{
"family_name": "Cot\u00e9",
"given_name": "Gerard L.",
"clpid": "Cot\u00e9-G-L"
}
],
"abstract": "We present both experimental measurements and Monte-Carlo-based simulations of the diffusely backscattered intensity patterns that arise from illuminating a turbid medium with a polarized laser beam. It is rigorously shown that, because of axial symmetry of the system, only seven elements of the effective backscattering Mueller matrix are independent. A new numerical method that allows simultaneous calculation of all 16 elements of the two-dimensional Mueller matrix is used. To validate our method we compared calculations to measurements from a turbid medium that consisted of polystyrene spheres of different sizes and concentrations in deionized water. The experimental and numerical results are in excellent agreement.",
"doi": "10.1364/AO.38.003399",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "1999-05-20",
"series_number": "15",
"volume": "38",
"issue": "15",
"pages": "3399-3408"
},
{
"id": "authors:hbe87-rqp31",
"collection": "authors",
"collection_id": "hbe87-rqp31",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170309-084712447",
"type": "article",
"title": "Two-dimensional depth-resolved Mueller matrix characterization of biological tissue by optical coherence tomography",
"author": [
{
"family_name": "Yao",
"given_name": "Gang",
"clpid": "Yao-Gang"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We built a polarization-sensitive optical coherence tomographic system and measured the two-dimensional depth-resolved full 4\u00d74 Mueller matrix of biological tissue for what is believed to be the first time. The Mueller matrix measurements, which we made by varying the polarization states of the light source and the detector, yielded a complete characterization of the polarization property of the tissue sample. The initial experimental results indicated that this new approach reveals some tissue structures that are not perceptible in standard optical coherence tomography.",
"doi": "10.1364/OL.24.000537",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "1999-04-15",
"series_number": "8",
"volume": "24",
"issue": "8",
"pages": "537-539"
},
{
"id": "authors:qnsmb-6wb28",
"collection": "authors",
"collection_id": "qnsmb-6wb28",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170309-085201604",
"type": "article",
"title": "Two-dimensional imaging of dense tissue-simulating turbid media by use of sonoluminescence",
"author": [
{
"family_name": "Shen",
"given_name": "Qimin",
"clpid": "Shen-Qimin"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "An optical imaging technique that is believed to be novel was developed for noninvasive cross-sectional imaging of tissuelike turbid media. By use of a sonoluminescence signal generated internally in the media with a 1-MHz continuous-wave ultrasound, two-dimensional images were produced for objects embedded in turbid media by a raster scan of the media. Multiple objects of different shapes were resolved with this imaging technique. The images showed a high contrast and good spatial resolution. The spatial resolution was limited by the focal size of the ultrasonic focus.",
"doi": "10.1364/AO.38.000246",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "1999-01-01",
"series_number": "1",
"volume": "38",
"issue": "1",
"pages": "246-252"
},
{
"id": "authors:a6d7c-pgj33",
"collection": "authors",
"collection_id": "a6d7c-pgj33",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170203-155553543",
"type": "article",
"title": "Development of tissue-simulating optical phantoms: poly-N-isopropylacrylamide solution entrapped inside a hydrogel",
"author": [
{
"family_name": "Marquez",
"given_name": "Guillermo",
"clpid": "Marquez-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Wang",
"given_name": "Changjie",
"clpid": "Wang-Changjie"
},
{
"family_name": "Hu",
"given_name": "Zhibing",
"clpid": "Hu-Zhibing"
}
],
"abstract": "The average turbid optical properties of the N-isopropylacrylamide (NIPA) polymer solution entrapped inside a polyacrylamide hydrogel (called an NIPA/PAAM gel system) were studied using a multiwavelength oblique-incidence reflectometer. The turbidity of such a system can be drastically changed by simply switching the temperature from below the low critical solution temperature of the NIPA, around 33\u00b0C, to above. The absorption coefficient and the reduced scattering coefficient were obtained as a function of wavelength for samples with selected NIPA and blue dextran concentrations. It is found that the scattering of the optical phantom comes from the NIPA polymer chains and the absorption from the blue dextran. The turbid optical properties of an NIPA/PAAM gel system can be tuned to simulate biological tissues at a specific wavelength by varying compositions of NIPA and blue dextran and further modified by controlling the temperature.",
"doi": "10.1088/0031-9155/44/1/022",
"issn": "0031-9155",
"publisher": "IOP",
"publication": "Physics in Medicine and Biology",
"publication_date": "1999-01",
"series_number": "1",
"volume": "44",
"issue": "1",
"pages": "309-318"
},
{
"id": "authors:xrpwz-40b76",
"collection": "authors",
"collection_id": "xrpwz-40b76",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170314-110617536",
"type": "article",
"title": "Cluster Model Description of Polarized Cu K-Edge Spectra of Nd_(2-x)Ce_xCuO_(4-\u03b4)",
"author": [
{
"family_name": "Liang",
"given_name": "G.",
"clpid": "Liang-G"
},
{
"family_name": "Li",
"given_name": "M.",
"clpid": "Li-M"
},
{
"family_name": "Markert",
"given_name": "J. T.",
"clpid": "Markert-J-T"
},
{
"family_name": "Wang",
"given_name": "L. V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Single crystals Nd_(2-x)Ce_xCuO_(4-\u03b4) with x=0.0 and 0.2 are studied by polarized X-ray absorption measurements at Cu K-edge. The positions and intensities of the 1s\u2192 4p\u03c3 transition features in the K-edge spectra are analyzed with a modified cluster model and functional curve fitting procedure. All of the experimental results including the energies of the spectral features, the energy separations between features and the variation of feature intensities, can be well explained by the cluster model parameters obtained from the curve fitting. Particularly, it is found that the charge transfer energy gap \u0394 in the Nd_(2-x)Ce_xCuO_(4-\u03b4) system decreases from about 1.4 eV at x=0 to 0.5 eV at x = 0.2. Our analysis in this paper provides a method for quantitative X-ray absorption spectroscopy (XAS) study of the charge transfer gap for electron-doped cuprate superconductors and related materials.",
"doi": "10.1142/S0217979298002519",
"issn": "0217-9792",
"publisher": "World Scientific Publishing",
"publication": "International Journal of Modern Physics B",
"publication_date": "1998-12-20",
"series_number": "29",
"volume": "12",
"issue": "29",
"pages": "3299-3305"
},
{
"id": "authors:5jvd7-ng639",
"collection": "authors",
"collection_id": "5jvd7-ng639",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170314-122702040",
"type": "article",
"title": "Cu K-Edge Study of (Tl_(0.5)Pb_(0.5))Sr_2Ca_(1-x)Y_xCu_2O_(7-\u03b4)",
"author": [
{
"family_name": "Liang",
"given_name": "G.",
"clpid": "Liang-G"
},
{
"family_name": "Liu",
"given_name": "R. S.",
"clpid": "Liu-R-S"
},
{
"family_name": "Wang",
"given_name": "L. V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Near-edge x-ray-absorption spectra at the Cu K-edge has been measured for (Tl_(0.5)Pb_(0.5))Sr_2Ca_(1-x)Y_xCu_2O_(7-\u03b4) compound series. It is found that both the intensity of the quadruple 1s \u2192 3d transition feature and the edge-energy decrease with increasing x. Our results show that the Cu valence decreases slightly with the substitution of Ca^(+2) by Y^(+3). This result, together with recent O K-edge result the O-2p holes are reduced by the substitution, indicates that electronic charge is transferred into the entire CuO_2 layers by the Y^(+3) for Ca^(+2) substitution.",
"doi": "10.1142/S0217979298002507",
"issn": "0217-9792",
"publisher": "World Scientific Publishing",
"publication": "International Journal of Modern Physics B",
"publication_date": "1998-12-20",
"series_number": "29",
"volume": "12",
"issue": "29",
"pages": "3296-3298"
},
{
"id": "authors:n5x2x-h3704",
"collection": "authors",
"collection_id": "n5x2x-h3704",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170309-090652612",
"type": "article",
"title": "Effect of molecular concentrations in tissue-simulating phantoms on images obtained using diffuse reflectance polarimetry",
"author": [
{
"family_name": "Mehr\u00fcbeo\u011flu",
"given_name": "Mehr\u00fcbe",
"clpid": "Mehr\u00fcbeo\u011flu-M"
},
{
"family_name": "Kehtarnavaz",
"given_name": "Nasser",
"clpid": "Kehtarnavaz-N"
},
{
"family_name": "Rastegar",
"given_name": "Sohi",
"clpid": "Rastegar-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We have investigated the possibility of using diffuse reflectance polarimetry to detect changes caused by different molecular compounds and concentrations in tissue-simulating phantoms. The effects of glucose, \u03b2-alanine and l-lysine at different concentrations in turbid media have been investigated separately. This approach is based on the effect of optical properties on the polarization state of light. The results show that this method has potential for determining changes in molecular concentrations in highly scattering biological media from polarization images.",
"doi": "10.1364/OE.3.000286",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "1998-09-28",
"series_number": "7",
"volume": "3",
"issue": "7",
"pages": "286-297"
},
{
"id": "authors:fpbb7-j5406",
"collection": "authors",
"collection_id": "fpbb7-j5406",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170309-090305443",
"type": "article",
"title": "Frequency-swept ultrasound-modulated optical tomography of scattering media",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Ku",
"given_name": "Geng",
"clpid": "Ku-Geng"
}
],
"abstract": "A novel frequency-swept ultrasound-modulated optical tomography technique was developed to image scattering media. A frequency-swept ultrasonic wave was used to modulate the laser light passing through a scattering medium. The modulated light was received by an optical detector and was heterodyned with a reference frequency sweep. The heterodyned signal was recorded in the time domain and was then analyzed in the frequency domain to yield a one-dimensional image along the ultrasonic axis. Multiple one-dimensional images obtained at various positions perpendicular to the ultrasonic axis were combined to yield a two-dimensional tomographic image of the medium.",
"doi": "10.1364/OL.23.000975",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "1998-06-15",
"series_number": "12",
"volume": "23",
"issue": "12",
"pages": "975-977"
},
{
"id": "authors:g6yg2-31k72",
"collection": "authors",
"collection_id": "g6yg2-31k72",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170313-134045406",
"type": "article",
"title": "Rapid modeling of diffuse reflectance of light in turbid slabs",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "An efficient and accurate hybrid model of the Monte Carlo technique and the diffusion theory was developed to simulate the diffuse reflectance of light in a turbid slab due to an infinitely narrow light beam. The narrow beam was normally incident on the top surface of the slab. The hybrid model was accurate in modeling the diffuse reflectance near the light source, where the diffusion theory was most inaccurate. The hybrid model was much faster than a pure Monte Carlo method by a factor as great as several hundred, depending on the optical properties, the thickness of the slab, and the settings of the hybrid and the Monte Carlo computations. The computation speed of the hybrid model was insensitive to the optical properties of the medium, in contrast to the pure Monte Carlo technique. The diffusion theory was accurate in modeling both the diffuse reflectance far from the source and the diffuse transmittance. The hybrid model and the diffusion theory should be used in conjunction for efficient and accurate computation of diffuse reflectance and diffuse transmittance.",
"doi": "10.1364/JOSAA.15.000936",
"issn": "1084-7529",
"publisher": "Optical Society of America",
"publication": "Journal of the Optical Society of America A",
"publication_date": "1998-04-01",
"series_number": "4",
"volume": "15",
"issue": "4",
"pages": "936-944"
},
{
"id": "authors:tdbk2-g8e76",
"collection": "authors",
"collection_id": "tdbk2-g8e76",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170313-132316717",
"type": "article",
"title": "Measurement and calculation of the two-dimensional backscattering Mueller matrix of a turbid medium",
"author": [
{
"family_name": "Cameron",
"given_name": "Brent D.",
"clpid": "Cameron-B-D"
},
{
"family_name": "Rakovi\u0107",
"given_name": "M. J.",
"clpid": "Rakovi\u0107-M-J"
},
{
"family_name": "Mehr\u00fcbeo\u011flu",
"given_name": "Mehr\u00fcbe",
"clpid": "Mehr\u00fcbeo\u011flu-M"
},
{
"family_name": "Kattawar",
"given_name": "George W.",
"clpid": "Kattawar-G-W"
},
{
"family_name": "Rastegar",
"given_name": "Sohi",
"clpid": "Rastegar-S"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Cot\u00e9",
"given_name": "Gerard L.",
"clpid": "Cot\u00e9-G-L"
}
],
"abstract": "We present both experimental and Monte Carlo\u2013based simulation results for the diffusely backscattered intensity patterns that arise from illumination of a turbid medium with a polarized laser beam. A numerical method that allows the calculation of all 16 elements of the two-dimensional Muller matrix is used; moreover, it is shown that only seven matrix elements are independent. To validate our method, we compared our simulations with experimental measurements, using a turbid medium consisting of 2.02\u2010\u00b5m-diameter polystyrene spheres suspended in deionized water. By varying the incident polarization and the analyzer optics for the experimental measurements, we obtained the diffuse backscattering Mueller matrix elements. The experimental and the numerical results are in good agreement.",
"doi": "10.1364/OL.23.000485",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "1998-04-01",
"series_number": "7",
"volume": "23",
"issue": "7",
"pages": "485-487"
},
{
"id": "authors:61dfx-aye36",
"collection": "authors",
"collection_id": "61dfx-aye36",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170313-134429560",
"type": "article",
"title": "Sonoluminescent tomography of strongly scattering media",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Shen",
"given_name": "Qimin",
"clpid": "Shen-Qimin"
}
],
"abstract": "A novel optical imaging technique called sonoluminescent tomography was developed for cross-sectional imaging of strongly scattering media noninvasively. Sonoluminescence, which was generated internally in the medium by cw ultrasound, was used to produce a two-dimensional image of an object embedded in a scattering medium by means of raster scanning the medium. The image had a high contrast and good spatial resolution. The spatial resolution was limited by the focal-spot size of the ultrasound, and one could improve the resolution by tightening the focus. This inexpensive imaging technique has potential applications in medicine and other fields related to scattering media.",
"doi": "10.1364/OL.23.000561",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "1998-04-01",
"series_number": "7",
"volume": "23",
"issue": "7",
"pages": "561-563"
},
{
"id": "authors:43gy8-ka927",
"collection": "authors",
"collection_id": "43gy8-ka927",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170313-133223733",
"type": "article",
"title": "Particle sizing in concentrated suspensions by use of steady-state, continuous-wave photon-migration techniques",
"author": [
{
"family_name": "Jiang",
"given_name": "Huabei",
"clpid": "Jiang-Huabei"
},
{
"family_name": "Marquez",
"given_name": "Guillermo",
"clpid": "Marquez-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We demonstrate a new approach for determining particle-size distribution in concentrated suspensions from spectral measurement of isotropic scattering coefficients by use of steady-state, continuous-wave photon-migration techniques. Successful recovery of particle-size distribution for TiO_2 suspensions in the form of log-normal functions is achieved through a regularized inverse algorithm, into which a synthesized scheme of Marquardt and Tikhonov regularizations has been incorporated. Our results for dense TiO_2 suspensions with three different particle concentrations are in excellent agreement with the size distribution as measured with x-ray sedimentation.",
"doi": "10.1364/OL.23.000394",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "1998-03-01",
"series_number": "5",
"volume": "23",
"issue": "5",
"pages": "394-396"
},
{
"id": "authors:tqvk3-m6665",
"collection": "authors",
"collection_id": "tqvk3-m6665",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170313-132928139",
"type": "article",
"title": "Optical tomography for biomedical applications",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Nonionizing optical tomography is a new and active research field although projection-light imaging was investigated as early as 1929. The optical properties of normal and diseased tissues are usually different despite the large variation of values in optical properties of the normal tissues alone. Therefore, it is possible to detect some breast cancers based on measurements of optical properties. In summary, optical techniques have the following advantages: (1) the use of nonionizing radiation, (2) the capability of measuring functional (physiological) parameters, (3) the potential high sensitivity to pathologic state of biological tissues, and (4) low cost. However, biomedical optics is a challenging research field requiring the participation of many diverse, talented scientists and engineers.",
"doi": "10.1109/51.664029",
"issn": "0739-5175",
"publisher": "IEEE",
"publication": "IEEE Engineering in Medicine and Biology Magazine",
"publication_date": "1998-03",
"series_number": "2",
"volume": "17",
"issue": "2",
"pages": "45-46"
},
{
"id": "authors:0x6hz-hj842",
"collection": "authors",
"collection_id": "0x6hz-hj842",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170309-085546921",
"type": "article",
"title": "Anisotropy in the absorption and scattering spectra of chicken breast tissue",
"author": [
{
"family_name": "Marquez",
"given_name": "Guillermo",
"clpid": "Marquez-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Lin",
"given_name": "Shao-Pow",
"clpid": "Lin-Shao-Pow"
},
{
"family_name": "Schwartz",
"given_name": "Jon A.",
"clpid": "Schwartz-J-A"
},
{
"family_name": "Thomsen",
"given_name": "Sharon L.",
"clpid": "Thomsen-S-L"
}
],
"abstract": "Oblique incidence reflectometry is a simple and accurate method for measuring the absorption and the reduced-scattering coefficients of turbid media. We used this technique to deduce absorption and reduced-scattering spectra from wavelength-resolved measurements of the relative diffuse reflectance profile of white light as a function of source\u2013detector distance. In this study, we measured the absorption and the reduced-scattering coefficients of chicken breast tissue in the visible range (400\u2013800 nm) with the oblique incidence probe oriented at 0\u00b0 and 90\u00b0 relative to the muscle fibers. We found that the deduced optical properties varied with the probe orientation. Measurements on homogenized chicken breast tissue yielded an absorption spectrum comparable with the average of the absorption spectra for 0\u00b0 and 90\u00b0 probe orientations measured on the unhomogenized tissue. The reduced-scattering spectrum for homogeneous tissue was greater than that acquired for unhomogenized tissue taken at either probe orientation. This experiment demonstrated the application of oblique-incidence, fiber-optic reflectometry to measurements on biological tissues and the effect of tissue structural anisotropy on optical properties.",
"doi": "10.1364/AO.37.000798",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "1998-02-01",
"series_number": "4",
"volume": "37",
"issue": "4",
"pages": "798-804"
},
{
"id": "authors:4pwqf-45689",
"collection": "authors",
"collection_id": "4pwqf-45689",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170313-140947669",
"type": "article",
"title": "Ultrasonic Modulation of Scattered Light in Turbid Media and a Potential Novel Tomography in Biomedicine",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "Ultrasonic modulation of scattered laser light was used to image objects buried in tissue-simulating turbid media. The ultrasonic wave focused into the turbid media modulated the laser light passing through the ultrasonic field. The modulated laser light collected by a photomultiplier tube reflected primarily the local mechanical and optical properties in the zone of ultrasonic modulation. A raster scanning over a heterogeneous turbid medium yielded an image of the medium based on the ultrasound-modulated optical signal. The detectability of modulated signal was estimated using diffusion theory. The dependence of the modulated signal on the off-axis distance of the detector from the optic axis and on the amplitude of ultrasound was studied. The mechanisms of ultrasonic modulation of scattered light are discussed. A theory based on the field autocorrelation function is reviewed as well.",
"doi": "10.1111/j.1751-1097.1998.tb05163.x",
"issn": "0031-8655",
"publisher": "Wiley",
"publication": "Photochemistry and Photobiology",
"publication_date": "1998-01",
"series_number": "1",
"volume": "67",
"issue": "1",
"pages": "41-49"
},
{
"id": "authors:crvky-pr868",
"collection": "authors",
"collection_id": "crvky-pr868",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190305-153255234",
"type": "article",
"title": "White light oblique incidence reflectometer for measuring absorption and reduced scattering spectra of tissue-like turbid media",
"author": [
{
"family_name": "Marquez",
"given_name": "Guillermo",
"clpid": "Marquez-G"
},
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
}
],
"abstract": "We designed a quick and inexpensive system for spectral measurements of optical properties including absorption coefficient and reduced scattering coefficient. The system was based on oblique incidence reflectometry.[1] A broad band light source was coupled into an optic fiber to deliver light obliquely to turbid media. Nine detection optic fibers were used to collect the diffuse reflectance as a function of source-detector distance. The relative diffuse reflectance profile was used to deduce the absorption and reduced scattering spectra. The system was able to acquire data in a wavelength range of 256 nm within a fraction of a second.",
"doi": "10.1364/oe.1.000454",
"issn": "1094-4087",
"publisher": "Optical Society of America",
"publication": "Optics Express",
"publication_date": "1997-12-22",
"series_number": "13",
"volume": "1",
"issue": "13",
"pages": "454-460"
},
{
"id": "authors:4yt35-mcf82",
"collection": "authors",
"collection_id": "4yt35-mcf82",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170313-143338769",
"type": "article",
"title": "Optimal beam size for light delivery to absorption-enhanced tumors buried in biological tissues and effect of multiple-beam delivery: a Monte Carlo study",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong V.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Nordquist",
"given_name": "Robert E.",
"clpid": "Nordquist-R-E"
},
{
"family_name": "Chen",
"given_name": "Wei R.",
"clpid": "Chen-Wei-R"
}
],
"abstract": "Optimal laser light delivery into turbid biological tissues was studied by using Monte Carlo simulations based on the delta-scattering technique. The goal was to deliver efficiently the maximum amount of optical power into buried tumors being treated while avoiding potential damage to normal tissue caused by strong optical power deposition underneath the tissue surface illuminated by the laser beam. The buried tumors were considered to have much higher absorption than the surrounding normal tissue because of selective uptake of the absorption-enhancement dye. The power delivering efficiency to buried tumors was investigated for various diameters of the laser beam. An optimal beam diameter was estimated to achieve the maximum product of the power coupling efficiency and the power delivered to the buried tumor. The distribution of power deposition was simulated for single-beam delivery and multiple-beam delivery as well. The simulated results showed that with an appropriate dye enhancement and an optimal laser delivery configuration, a high selectivity for laser treatment of tumor could be achieved.",
"doi": "10.1364/AO.36.008286",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "1997-11-01",
"series_number": "31",
"volume": "36",
"issue": "31",
"pages": "8286-8291"
},
{
"id": "authors:mw37n-ens85",
"collection": "authors",
"collection_id": "mw37n-ens85",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170313-141533137",
"type": "article",
"title": "CONV\u2014convolution for responses to a finite diameter photon beam incident on multi-layered tissues",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Jacques",
"given_name": "Steven L.",
"clpid": "Jacques-S-L"
},
{
"family_name": "Zheng",
"given_name": "Liqiong",
"clpid": "Zheng-Liqiong"
}
],
"abstract": "A convolution program (CONV) solving responses to a collimated finite diameter photon beam perpendicularly incident on a multi-layered tissue has been coded in ANSI Standard C, hence, the program can be executed on various computers. The program, employing an extended trapezoidal rule for integration, convolves the responses to an infinitely narrow photon beam computed by a companion program (MCML). Dynamic data allocation is used for CONV as well as MCML, therefore, the number of tissue layers and grid elements of the grid system can be varied at run time. The potential error due to not scoring the first photon-tissue interactions separately is illustrated. The program, including the source code, has been in the public domain since 1992 and can be downloaded from the web site at http://biomed.tamu.edu/~lw.",
"doi": "10.1016/S0169-2607(97)00021-7",
"issn": "0169-2607",
"publisher": "Elsevier",
"publication": "Computer Methods and Programs in Biomedicine",
"publication_date": "1997-11",
"series_number": "3",
"volume": "54",
"issue": "3",
"pages": "141-150"
},
{
"id": "authors:sgvhv-hra27",
"collection": "authors",
"collection_id": "sgvhv-hra27",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190305-153255323",
"type": "article",
"title": "Ultrasound-modulated optical tomography of absorbing objects buried in dense tissue-simulating turbid media",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Zhao",
"given_name": "Xuemei",
"clpid": "Zhao-Xuemei"
}
],
"abstract": "Continuous-wave ultrasonic modulation of scattered laser light was used to image objects buried in tissue-simulating turbid media. The buried object had an absorption coefficient greater than the background turbid medium. The ultrasonic wave that was focused into the turbid media modulated the laser light that passed through the ultrasonic field. The modulated laser light that was collected by a photomultiplier tube reflected the local mechanical and optical properties in the zone of ultrasonic modulation. Objects buried in the middle plane of 5-cm-thick dense turbid media were imaged with millimeter resolution through the scanning and detecting alterations of the ultrasound-modulated optical signal. The optical properties of the dense turbid media included an absorption coefficient of 0.1 cm^(-1) and a reduced scattering coefficient of 10 cm^(-1) and were comparable with those of biological tissues in the visible and near-IR ranges. The dependence of the ultrasound-modulated optical signal on the off-axis distance of the detector from the optic axis and the area of the detector was studied as well.",
"doi": "10.1364/ao.36.007277",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "1997-10-01",
"series_number": "28",
"volume": "36",
"issue": "28",
"pages": "7277-7282"
},
{
"id": "authors:n4asx-hmb65",
"collection": "authors",
"collection_id": "n4asx-hmb65",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170313-142220904",
"type": "article",
"title": "Measurement of tissue optical properties by the use of oblique-incidence optical fiber reflectometry",
"author": [
{
"family_name": "Lin",
"given_name": "Shao-Pow",
"clpid": "Lin-Shao-Pow"
},
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Jacques",
"given_name": "Steven L.",
"clpid": "Jacques-S-L"
},
{
"family_name": "Tittel",
"given_name": "Frank K.",
"clpid": "Tittel-F-K"
}
],
"abstract": "Fiber-optic-based oblique-incidence reflectometry is a simple and accurate method for measuring the absorption and reduced scattering coefficients \u03bc_a and \u03bc_s' of semi-infinite turbid media. Obliquely incident light produces a spatial distribution of diffuse reflectance that is not centered about the point of light entry. The amount of shift in the center of diffuse reflectance is directly related to the medium's diffusion length D. We developed a fiber-optic probe to deliver light obliquely and sample the relative profile of diffuse reflectance. Measurement in absolute units is not necessary. From the profile, it was possible to measure D, perform a curve fit for the effective attenuation coefficient \u03bc_(eff), and then calculate \u03bc_a and \u03bc_s'. This method was verified with Monte Carlo simulations and tested on tissue phantoms. Our measurements of D and \u03bc_(eff) had an accuracy of approximately 5%, thus giving us 10% and 5% accuracy for \u03bc_a and \u03bc_s', respectively.",
"doi": "10.1364/AO.36.000136",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "1997-01-01",
"series_number": "1",
"volume": "36",
"issue": "1",
"pages": "136-143"
},
{
"id": "authors:7qvsy-gpy22",
"collection": "authors",
"collection_id": "7qvsy-gpy22",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190305-153255411",
"type": "article",
"title": "Biological laser action",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Liu",
"given_name": "Da",
"clpid": "Liu-Da"
},
{
"family_name": "He",
"given_name": "Nancy",
"clpid": "He-Nancy"
},
{
"family_name": "Jacques",
"given_name": "Steven L.",
"clpid": "Jacques-S-L"
},
{
"family_name": "Thomsen",
"given_name": "Sharon L.",
"clpid": "Thomsen-S-L"
}
],
"abstract": "The narrowing of the spectral linewidth and the increasing of the peak intensity characteristic of laser action were observed in emission spectra of dye-infused biological tissues. The tissue was infused with a solution of Rhodamine 640 perchlorate in ethanol and then excited with frequency-doubled Q-switched Nd:YAG laser pulses. The dependence of emission linewidth on the excitation radiant exposure and dye concentration was investigated. Laser action was also observed in biologically compatible fluorescein sodium dye dissolved in phosphate-buffered saline mixed with scattering polystyrene spheres. The sharp spectral peaks of laser action in tissues may find applications in the detection of superficial disease.",
"doi": "10.1364/ao.35.001775",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "1996-04-01",
"series_number": "10",
"volume": "35",
"issue": "10",
"pages": "1775-1779"
},
{
"id": "authors:8yyed-jt564",
"collection": "authors",
"collection_id": "8yyed-jt564",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170313-150303167",
"type": "article",
"title": "The influence of boundary conditions on the accuracy of diffusion theory in time-resolved reflectance spectroscopy of biological tissues",
"author": [
{
"family_name": "Hielscher",
"given_name": "Andreas H.",
"clpid": "Hielscher-A-H"
},
{
"family_name": "Jacques",
"given_name": "Steven L.",
"clpid": "Jacques-S-L"
},
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Tittel",
"given_name": "Frank K.",
"clpid": "Tittel-F-K"
}
],
"abstract": "The applicability of diffusion theory for the determination of tissue optical properties from time-resolved reflectance spectroscopy is investigated. Analytical expressions from diffusion theory using the three most commonly assumed boundary conditions at the air-tissue interface are compared with time-resolved Monte Carlo simulations and measurements on tissue phantoms. The effects of the choice of the boundary conditions on the accuracy of the findings for the optical parameters are quantified, and criteria for accurate curve-fitting algorithms are developed.",
"doi": "10.1088/0031-9155/40/11/013",
"issn": "0031-9155",
"publisher": "IOP",
"publication": "Physics in Medicine and Biology",
"publication_date": "1995-11",
"series_number": "11",
"volume": "40",
"issue": "11",
"pages": "1957-1975"
},
{
"id": "authors:0ndwh-62936",
"collection": "authors",
"collection_id": "0ndwh-62936",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160616-102030882",
"type": "article",
"title": "MCML-Monte Carlo modeling of light transport in multi-layered tissues",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Jacques",
"given_name": "Steven L.",
"clpid": "Jacques-S-L"
},
{
"family_name": "Zheng",
"given_name": "Liqiong",
"clpid": "Zheng-Liqiong"
}
],
"abstract": "A Monte Carlo model of steady-state light transport in multi-layered tissues (MCML) has been coded in ANSI Standard C; therefore, the program can be used on various computers. Dynamic data allocation is used for MCML, hence the number of tissue layers and grid elements of the grid system can be varied by users at run time. The coordinates of the simulated data for each grid element in the radial and angular directions are optimized. Some of the MCML computational results have been verified with those of other theories or other investigators. The program, including the source code, has been in the public domain since 1992.",
"doi": "10.1016/0169-2607(95)01640-F",
"issn": "0169-2607",
"publisher": "Elsevier",
"publication": "Computer Methods and Programs in Biomedicine",
"publication_date": "1995-07",
"series_number": "2",
"volume": "47",
"issue": "2",
"pages": "131-146"
},
{
"id": "authors:crg1p-swp49",
"collection": "authors",
"collection_id": "crg1p-swp49",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170313-151029201",
"type": "article",
"title": "Use of a laser beam with an oblique angle of incidence to measure the reduced scattering coefficient of a turbid medium",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Jacques",
"given_name": "Steven L.",
"clpid": "Jacques-S-L"
}
],
"abstract": "A simple and quick approach is used to measure the reduced scattering coefficient (\u03bc_s') of a semi-infinite turbid medium having a much smaller absorption coefficient than \u03bc_s'. A laser beam with an oblique angle of incidence to the medium causes the center of the diffuse reflectance that is several transport mean-free paths away from the incident point to shift away from the point of incidence by an amount \u0394x. This amount is used to compute \u03bc_s' by \u03bc_s' = sin(\u03b1_i)/(n\u0394x), where n is the refractive index of the turbid medium divided by that of the incident medium and \u03b1_i is the angle of incidence measured from the surface normal. For a turbid medium having an absorption coefficient comparable with \u03bc_s', a revision to the above formula is made. This method is tested theoretically by Monte Carlo simulations and experimentally by a video reflectometer.",
"doi": "10.1364/AO.34.002362",
"issn": "0003-6935",
"publisher": "Optical Society of America",
"publication": "Applied Optics",
"publication_date": "1995-05-01",
"series_number": "13",
"volume": "34",
"issue": "13",
"pages": "2362-2366"
},
{
"id": "authors:47grb-rym48",
"collection": "authors",
"collection_id": "47grb-rym48",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160614-110751953",
"type": "article",
"title": "Continuous-wave ultrasonic modulation of scattered laser light to image objects in turbid media",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Jacques",
"given_name": "Steven L.",
"clpid": "Jacques-S-L"
},
{
"family_name": "Zhao",
"given_name": "Xuemei",
"clpid": "Zhao-Xuemei"
}
],
"abstract": "Continuous-wave ultrasonic modulation of scattered laser light has been used to image objects in tissue-simulating turbid media for what is to our knowledge the first time. The ultrasound wave focused into the turbid media modulates the laser light passing through the ultrasonic focal zone. The modulated laser light collected by a photomultiplier tube reflects the local mechanical and optical properties in the focal zone. Buried objects are located with millimeter resolution by scanning and detecting alterations of the modulated optical signal. This technique has the potential to provide a noninvasive, nonionizing, inexpensive diagnostic tool for diseases such as breast cancer.",
"doi": "10.1364/OL.20.000629",
"issn": "0146-9592",
"publisher": "Optical Society of America",
"publication": "Optics Letters",
"publication_date": "1995-03-15",
"series_number": "6",
"volume": "20",
"issue": "6",
"pages": "629-631"
},
{
"id": "authors:na0es-8gm44",
"collection": "authors",
"collection_id": "na0es-8gm44",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170313-152932083",
"type": "article",
"title": "Error estimation of measuring total interaction coefficients of turbid media using collimated light transmission",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Jacques",
"given_name": "Steven L.",
"clpid": "Jacques-S-L"
}
],
"abstract": "The error of measuring the total interaction coefficients of turbid media using collimated light transmission was estimated with an analytical expression, which was verified with accurate Monte Carlo simulations. The expression is based on the Henyey-Greenstein phase function of scattering and the probabilities of non-scattered and singly scattered photons transmitted through a tissue slab with a unit anisotropy factor.",
"doi": "10.1088/0031-9155/39/12/015",
"issn": "0031-9155",
"publisher": "IOP",
"publication": "Physics in Medicine and Biology",
"publication_date": "1994-12",
"series_number": "12",
"volume": "39",
"issue": "12",
"pages": "2349-2354"
},
{
"id": "authors:t5b2j-0y620",
"collection": "authors",
"collection_id": "t5b2j-0y620",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170313-155910653",
"type": "article",
"title": "Optimized radial and angular positions in Monte Carlo modeling",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Jacques",
"given_name": "Steven L.",
"clpid": "Jacques-S-L"
}
],
"abstract": "In Monte Carlo simulations of light transport in tissues, a grid system is set up to score physical quantities. This study of cylindrically symmetrical problems found that the optimized radial and angular positions for the averaged physical quantities in each grid element are off-center. The error of the extrapolated physical quantities at the light-incidence point using the centered radial positions is up to 14.3%.",
"doi": "10.1118/1.597351",
"issn": "0094-2405",
"publisher": "American Association of Physicists in Medicine",
"publication": "Medical Physics",
"publication_date": "1994-07",
"series_number": "7",
"volume": "21",
"issue": "7",
"pages": "1081-1083"
},
{
"id": "authors:9j8g5-sy637",
"collection": "authors",
"collection_id": "9j8g5-sy637",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170314-074849164",
"type": "article",
"title": "Hybrid model of Monte Carlo simulation and diffusion theory for light reflectance by turbid media",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Jacques",
"given_name": "Steven L.",
"clpid": "Jacques-S-L"
}
],
"abstract": "Light reflectance by semi-infinite turbid media is modeled by a hybrid of Monte Carlo simulation and diffusion theory, which combines the accuracy of Monte Carlo simulation near the source and the speed of diffusion theory distant from the source. For example, when the turbid medium has the following optical properties\u2014absorption coefficient 1 cm^(-1), scattering coefficient 100 cm^(-1), anisotropy 0.9, and refractive-index-matched boundary\u2014the hybrid simulation is 7 times faster than the pure Monte Carlo simulation (100,000 photon packets were traced), and the difference between the two simulations is within 2 standard deviations of the Monte Carlo simulation.",
"doi": "10.1364/JOSAA.10.001746",
"issn": "1084-7529",
"publisher": "Optical Society of America",
"publication": "Journal of the Optical Society of America A",
"publication_date": "1993-08-01",
"series_number": "8",
"volume": "10",
"issue": "8",
"pages": "1746-1752"
},
{
"id": "authors:p56qq-efw20",
"collection": "authors",
"collection_id": "p56qq-efw20",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170314-082825747",
"type": "article",
"title": "Isomers of gallium arsenide cluster ions",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Chibante",
"given_name": "L. P. F.",
"clpid": "Chibante-L-P-F"
},
{
"family_name": "Tittel",
"given_name": "F. K.",
"clpid": "Tittel-F-K"
},
{
"family_name": "Curl",
"given_name": "R. F.",
"clpid": "Curl-R-F"
},
{
"family_name": "Smalley",
"given_name": "R. E.",
"clpid": "Smalley-R-E"
}
],
"abstract": "Gallium arsenide cluster ions were generated by laser vaporization in a supersonic nozzle, trapped in a Fourier transform ion-cyclotron resonance mass spectrometer, and allowed to react with NH_3 forming addition complexes with the cluster cations. With excess NH_3, Ga_xAs_y(NH_3)^+_z with the same GaAs composition (x+y) was observed with several values of z. This observation of different numbers of chemisorbed NH_3 molecules at completion is explained in terms of the existence of multiple isomers of positive GaAs clusters. Negative Ga_xAs^\u2212_y clusters were found to be inert toward NH_3.",
"doi": "10.1016/0009-2614(92)85538-L",
"issn": "0009-2614",
"publisher": "Elsevier",
"publication": "Chemical Physics Letters",
"publication_date": "1992-06-26",
"series_number": "3",
"volume": "194",
"issue": "3",
"pages": "217-222"
},
{
"id": "authors:ydgcs-0px93",
"collection": "authors",
"collection_id": "ydgcs-0px93",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170314-083609172",
"type": "article",
"title": "Fullerenes with metals inside",
"author": [
{
"family_name": "Chai",
"given_name": "Yan",
"clpid": "Chai-Yan"
},
{
"family_name": "Guo",
"given_name": "Ting",
"clpid": "Guo-Ting"
},
{
"family_name": "Jin",
"given_name": "Changming",
"clpid": "Jin-Changming"
},
{
"family_name": "Haufler",
"given_name": "Robert E.",
"clpid": "Haufler-R-E"
},
{
"family_name": "Chibante",
"given_name": "L. P. Felipe",
"clpid": "Chibante-L-P-F"
},
{
"family_name": "Fure",
"given_name": "Jan",
"clpid": "Fure-Jan"
},
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Alford",
"given_name": "J. Michael",
"clpid": "Alford-J-M"
},
{
"family_name": "Smalley",
"given_name": "Richard E.",
"clpid": "Smalley-R-E"
}
],
"abstract": "Fullerenes with a single lanthanum atom trapped on the inside of the carbon cage were produced by laser vaporization of a lanthanum oxide/graphite composite rod in a flow of argon gas at 1200 \u00b0C. When sublimed with C_(60) and C_(70), they formed \nan air-stable film containing principally LaC_(60), LaC_(70), LaC_(74), and LaC_(82). When dissolved in toluene and exposed to air, \nLaC_(82) was found to be uniquely stable. Evidence was also obtained for coalescence reactions between these fullerenes at\nhigh temperatures to form larger cages with as many as three lanthanum atoms inside. Indications have also been obtained \nfor the successful production of KC_(60), C_(59)B, and KC_(59)B where the boron has substituted for a carbon in the soccerball cage. \nThe use of the @ symbol is advocated for specifying such complex fullerenes as (K@C_(59)B).",
"doi": "10.1021/j100173a002",
"issn": "0022-3654",
"publisher": "American Chemical Society",
"publication": "Journal of Physical Chemistry",
"publication_date": "1991-10-03",
"series_number": "20",
"volume": "95",
"issue": "20",
"pages": "7564-7568"
},
{
"id": "authors:64hfd-sxc63",
"collection": "authors",
"collection_id": "64hfd-sxc63",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170314-083237273",
"type": "article",
"title": "Electronic structure of small GaAs clusters",
"author": [
{
"family_name": "Lou",
"given_name": "L.",
"clpid": "Lou-L"
},
{
"family_name": "Wang",
"given_name": "L.",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Chibante",
"given_name": "L. P. F.",
"clpid": "Chibante-L-P-F"
},
{
"family_name": "Laaksonen",
"given_name": "R. T.",
"clpid": "Laaksonen-R-T"
},
{
"family_name": "Nordlander",
"given_name": "P.",
"orcid": "0000-0002-1633-2937",
"clpid": "Nordlander-P"
},
{
"family_name": "Smalley",
"given_name": "R. E.",
"clpid": "Smalley-R-E"
}
],
"abstract": "The electronic structure of small Ga_xAs_y clusters (x+y\u226410) are calculated using the local density method. The calculation shows that even\u2010numbered clusters tend to be singlets, as opposed to odd\u2010numbered clusters which are open shell systems. This is in agreement with the experimental observations of even/odd alternations of the electron affinity and ionization potential. In the larger clusters, the atoms prefer an alternating bond arrangement; charge transfers are observed from Ga sites to As sites. This observation is also in agreement with recent chemisorption studies of ammonia on GaAs clusters. The close agreement between theoretical calculations and experimental results, together with the rich variation of electronic properties of GaAs clusters with composition makes GaAs clusters an ideal prototype system for the study of how electronic structure influences chemical reactivity.",
"doi": "10.1063/1.460135",
"issn": "0021-9606",
"publisher": "American Institute of Physics",
"publication": "Journal of Chemical Physics",
"publication_date": "1991-03",
"series_number": "12",
"volume": "94",
"issue": "12",
"pages": "8015-8020"
},
{
"id": "authors:adhey-q0h35",
"collection": "authors",
"collection_id": "adhey-q0h35",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170314-102731033",
"type": "article",
"title": "Ammonia chemisorption on gallium arsenide clusters",
"author": [
{
"family_name": "Wang",
"given_name": "Lihong",
"orcid": "0000-0001-9783-4383",
"clpid": "Wang-Lihong-V"
},
{
"family_name": "Chibante",
"given_name": "L. P. F.",
"clpid": "Chibante-L-P-F"
},
{
"family_name": "Tittel",
"given_name": "F. K.",
"clpid": "Tittel-F-K"
},
{
"family_name": "Curl",
"given_name": "R. F.",
"clpid": "Curl-R-F"
},
{
"family_name": "Smalley",
"given_name": "R. E.",
"clpid": "Smalley-R-E"
}
],
"abstract": "Gallium arsenide clusters in the 6\u201316-atom size range were generated by laser vaporization in a supersonic nozzle and trapped as positive ions in Fourier transform ion-cyclotron resonance mass spectrometer. Measurements of the rate of attachment of ammonia revealed that all clusters larger than seven atoms were most reactive near the 11 composition ratio of gallium/arsenic. The results suggest that even at this small size the clusters begin to adopt the alternating gallium\u2014arsenic bonding arrangement characteristic of bulk GaAs crystal surfaces where gallium\u2014arsenic bonding activates gallium atoms for ammonia chemisorption.",
"doi": "10.1016/S0009-2614(90)87123-9",
"issn": "0009-2614",
"publisher": "Elsevier",
"publication": "Chemical Physics Letters",
"publication_date": "1990-09-14",
"series_number": "5",
"volume": "172",
"issue": "5",
"pages": "335-340"
}
]