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Junjie Yao

Associate Professor of Biomedical Engineering
Biomedical Engineering
Room 1427, Fitzpatrick Ciemas, 101 Science Drive, PO Box 90281, Durham, NC 27708
Hudson Hall Annex 261, Durham, NC 27708
Office hours Monday to Friday: 9:30 am to 6:00 pm (walk-in welcome)  

Selected Publications


Longitudinal intravital imaging of mouse placenta.

Journal Article Sci Adv · March 22, 2024 Studying placental functions is crucial for understanding pregnancy complications. However, imaging placenta is challenging due to its depth, volume, and motion distortions. In this study, we have developed an implantable placenta window in mice that enabl ... Full text Link to item Cite

Advanced 3D imaging and organoid bioprinting for biomedical research and therapeutic applications.

Journal Article Advanced drug delivery reviews · March 2024 Organoid cultures offer a valuable platform for studying organ-level biology, allowing for a closer mimicry of human physiology compared to traditional two-dimensional cell culture systems or non-primate animal models. While many organoid cultures use cell ... Full text Cite

Multi-molecular hyperspectral PRM-SRS microscopy.

Journal Article Nat Commun · February 21, 2024 Lipids play crucial roles in many biological processes. Mapping spatial distributions and examining the metabolic dynamics of different lipid subtypes in cells and tissues are critical to better understanding their roles in aging and diseases. Commonly use ... Full text Link to item Cite

On the Importance of Low-Frequency Signals in Functional and Molecular Photoacoustic Computed Tomography.

Journal Article IEEE transactions on medical imaging · February 2024 In photoacoustic computed tomography (PACT) with short-pulsed laser excitation, wideband acoustic signals are generated in biological tissues with frequencies related to the effective shapes and sizes of the optically absorbing targets. Low-frequency photo ... Full text Cite

Sounding out the dynamics: a concise review of high-speed photoacoustic microscopy.

Journal Article Journal of biomedical optics · January 2024 SignificancePhotoacoustic microscopy (PAM) offers advantages in high-resolution and high-contrast imaging of biomedical chromophores. The speed of imaging is critical for leveraging these benefits in both preclinical and clinical settings. Ongoing ... Full text Cite

Shock waves generated by toroidal bubble collapse are imperative for kidney stone dusting during Holmium:YAG laser lithotripsy.

Journal Article Ultrasonics sonochemistry · December 2023 Holmium:yttrium-aluminum-garnet (Ho:YAG) laser lithotripsy (LL) has been the treatment of choice for kidney stone disease for more than two decades, yet the mechanisms of action are not completely clear. Besides photothermal ablation, recent evidence sugge ... Full text Cite

Self-enhancing sono-inks enable deep-penetration acoustic volumetric printing.

Journal Article Science (New York, N.Y.) · December 2023 Volumetric printing, an emerging additive manufacturing technique, builds objects with enhanced printing speed and surface quality by forgoing the stepwise ink-renewal step. Existing volumetric printing techniques almost exclusively rely on light energy to ... Full text Cite

Theoretical and experimental study on the detection limit of the micro-ring resonator based ultrasound point detectors.

Journal Article Photoacoustics · December 2023 Combining the diffusive laser excitation and the photoacoustic signals detection, photoacoustic computed tomography (PACT) is uniquely suited for deep tissue imaging. A diffraction-limited ultrasound point detector is highly desirable for maximizing the sp ... Full text Cite

A frequency-domain model-based reconstruction method for transcranial photoacoustic imaging: A 2D numerical investigation.

Journal Article Photoacoustics · October 2023 Phase aberration caused by the skull is a major barrier to achieving high quality photoacoustic images of human and non-human primates' brains. To address this issue, time-reversal methods have been used but they are computationally demanding and slow due ... Full text Cite

Multiscale photoacoustic tomography using reversibly switchable thermochromics.

Journal Article Journal of biomedical optics · August 2023 SignificanceBased on acoustic detection of optical absorption, photoacoustic tomography (PAT) allows functional and molecular imaging beyond the optical diffusion limit with high spatial resolution. However, multispectral functional and molecular ... Full text Cite

Miniaturized Stacked Transducer for Intravascular Sonothrombolysis With Internal-Illumination Photoacoustic Imaging Guidance and Clot Characterization.

Journal Article IEEE transactions on bio-medical engineering · August 2023 Thromboembolism in blood vessels can lead to stroke or heart attack and even sudden death unless brought under control. Sonothrombolysis enhanced by ultrasound contrast agents has shown promising outcome on effective treatment of thromboembolism. Intravasc ... Full text Cite

Epinephrine-induced Effects on Cerebral Microcirculation and Oxygenation Dynamics Using Multimodal Monitoring and Functional Photoacoustic Microscopy.

Journal Article Anesthesiology · August 1, 2023 BACKGROUND: The administration of epinephrine after severe refractory hypotension, shock, or cardiac arrest restores systemic blood flow and major vessel perfusion but may worsen cerebral microvascular perfusion and oxygen delivery through vasoconstriction ... Full text Link to item Cite

Vortex-ultrasound for microbubble-mediated thrombolysis of retracted clots.

Journal Article Applied physics letters · August 2023 Endovascular sonothrombolysis has gained significant attention due to its benefits, including direct targeting of the thrombus with sonication and reduced side effects. However, the small aperture of endovascular transducers restricts the improvement of th ... Full text Cite

Integrated Photoacoustic, Ultrasound, and Angiographic Tomography (PAUSAT) for NonInvasive Whole-Brain Imaging of Ischemic Stroke.

Journal Article J Vis Exp · June 2, 2023 Presented here is an experimental ischemic stroke study using our newly developed noninvasive imaging system that integrates three acoustic-based imaging technologies: photoacoustic, ultrasound, and angiographic tomography (PAUSAT). Combining these three m ... Full text Link to item Cite

The sound of blood: photoacoustic imaging in blood analysis.

Journal Article Medicine in novel technology and devices · June 2023 Blood analysis is a ubiquitous and critical aspect of modern medicine. Analyzing blood samples requires invasive techniques, various testing systems, and samples are limited to relatively small volumes. Photoacoustic imaging (PAI) is a novel imaging modali ... Full text Cite

Mouse Cardiac Arrest Model for Brain Imaging and Brain Physiology Monitoring During Ischemia and Resuscitation.

Journal Article J Vis Exp · April 14, 2023 Most cardiac arrest (CA) survivors experience varying degrees of neurologic deficits. To understand the mechanisms that underpin CA-induced brain injury and, subsequently, develop effective treatments, experimental CA research is essential. To this end, a ... Full text Link to item Cite

Photoacoustic imaging with limited sampling: a review of machine learning approaches.

Journal Article Biomedical optics express · April 2023 Photoacoustic imaging combines high optical absorption contrast and deep acoustic penetration, and can reveal structural, molecular, and functional information about biological tissue non-invasively. Due to practical restrictions, photoacoustic imaging sys ... Full text Cite

Sustained overexpression of spliced X-box-binding protein-1 in neurons leads to spontaneous seizures and sudden death in mice.

Journal Article Commun Biol · March 9, 2023 The underlying etiologies of seizures are highly heterogeneous and remain incompletely understood. While studying the unfolded protein response (UPR) pathways in the brain, we unexpectedly discovered that transgenic mice (XBP1s-TG) expressing spliced X-box ... Full text Link to item Cite

Longitudinal intravital imaging of mouse placenta.

Journal Article Sci Adv · March 22, 2024 Studying placental functions is crucial for understanding pregnancy complications. However, imaging placenta is challenging due to its depth, volume, and motion distortions. In this study, we have developed an implantable placenta window in mice that enabl ... Full text Link to item Cite

Advanced 3D imaging and organoid bioprinting for biomedical research and therapeutic applications.

Journal Article Advanced drug delivery reviews · March 2024 Organoid cultures offer a valuable platform for studying organ-level biology, allowing for a closer mimicry of human physiology compared to traditional two-dimensional cell culture systems or non-primate animal models. While many organoid cultures use cell ... Full text Cite

Multi-molecular hyperspectral PRM-SRS microscopy.

Journal Article Nat Commun · February 21, 2024 Lipids play crucial roles in many biological processes. Mapping spatial distributions and examining the metabolic dynamics of different lipid subtypes in cells and tissues are critical to better understanding their roles in aging and diseases. Commonly use ... Full text Link to item Cite

On the Importance of Low-Frequency Signals in Functional and Molecular Photoacoustic Computed Tomography.

Journal Article IEEE transactions on medical imaging · February 2024 In photoacoustic computed tomography (PACT) with short-pulsed laser excitation, wideband acoustic signals are generated in biological tissues with frequencies related to the effective shapes and sizes of the optically absorbing targets. Low-frequency photo ... Full text Cite

Sounding out the dynamics: a concise review of high-speed photoacoustic microscopy.

Journal Article Journal of biomedical optics · January 2024 SignificancePhotoacoustic microscopy (PAM) offers advantages in high-resolution and high-contrast imaging of biomedical chromophores. The speed of imaging is critical for leveraging these benefits in both preclinical and clinical settings. Ongoing ... Full text Cite

Shock waves generated by toroidal bubble collapse are imperative for kidney stone dusting during Holmium:YAG laser lithotripsy.

Journal Article Ultrasonics sonochemistry · December 2023 Holmium:yttrium-aluminum-garnet (Ho:YAG) laser lithotripsy (LL) has been the treatment of choice for kidney stone disease for more than two decades, yet the mechanisms of action are not completely clear. Besides photothermal ablation, recent evidence sugge ... Full text Cite

Self-enhancing sono-inks enable deep-penetration acoustic volumetric printing.

Journal Article Science (New York, N.Y.) · December 2023 Volumetric printing, an emerging additive manufacturing technique, builds objects with enhanced printing speed and surface quality by forgoing the stepwise ink-renewal step. Existing volumetric printing techniques almost exclusively rely on light energy to ... Full text Cite

Theoretical and experimental study on the detection limit of the micro-ring resonator based ultrasound point detectors.

Journal Article Photoacoustics · December 2023 Combining the diffusive laser excitation and the photoacoustic signals detection, photoacoustic computed tomography (PACT) is uniquely suited for deep tissue imaging. A diffraction-limited ultrasound point detector is highly desirable for maximizing the sp ... Full text Cite

A frequency-domain model-based reconstruction method for transcranial photoacoustic imaging: A 2D numerical investigation.

Journal Article Photoacoustics · October 2023 Phase aberration caused by the skull is a major barrier to achieving high quality photoacoustic images of human and non-human primates' brains. To address this issue, time-reversal methods have been used but they are computationally demanding and slow due ... Full text Cite

Multiscale photoacoustic tomography using reversibly switchable thermochromics.

Journal Article Journal of biomedical optics · August 2023 SignificanceBased on acoustic detection of optical absorption, photoacoustic tomography (PAT) allows functional and molecular imaging beyond the optical diffusion limit with high spatial resolution. However, multispectral functional and molecular ... Full text Cite

Miniaturized Stacked Transducer for Intravascular Sonothrombolysis With Internal-Illumination Photoacoustic Imaging Guidance and Clot Characterization.

Journal Article IEEE transactions on bio-medical engineering · August 2023 Thromboembolism in blood vessels can lead to stroke or heart attack and even sudden death unless brought under control. Sonothrombolysis enhanced by ultrasound contrast agents has shown promising outcome on effective treatment of thromboembolism. Intravasc ... Full text Cite

Epinephrine-induced Effects on Cerebral Microcirculation and Oxygenation Dynamics Using Multimodal Monitoring and Functional Photoacoustic Microscopy.

Journal Article Anesthesiology · August 1, 2023 BACKGROUND: The administration of epinephrine after severe refractory hypotension, shock, or cardiac arrest restores systemic blood flow and major vessel perfusion but may worsen cerebral microvascular perfusion and oxygen delivery through vasoconstriction ... Full text Link to item Cite

Vortex-ultrasound for microbubble-mediated thrombolysis of retracted clots.

Journal Article Applied physics letters · August 2023 Endovascular sonothrombolysis has gained significant attention due to its benefits, including direct targeting of the thrombus with sonication and reduced side effects. However, the small aperture of endovascular transducers restricts the improvement of th ... Full text Cite

Integrated Photoacoustic, Ultrasound, and Angiographic Tomography (PAUSAT) for NonInvasive Whole-Brain Imaging of Ischemic Stroke.

Journal Article J Vis Exp · June 2, 2023 Presented here is an experimental ischemic stroke study using our newly developed noninvasive imaging system that integrates three acoustic-based imaging technologies: photoacoustic, ultrasound, and angiographic tomography (PAUSAT). Combining these three m ... Full text Link to item Cite

The sound of blood: photoacoustic imaging in blood analysis.

Journal Article Medicine in novel technology and devices · June 2023 Blood analysis is a ubiquitous and critical aspect of modern medicine. Analyzing blood samples requires invasive techniques, various testing systems, and samples are limited to relatively small volumes. Photoacoustic imaging (PAI) is a novel imaging modali ... Full text Cite

Mouse Cardiac Arrest Model for Brain Imaging and Brain Physiology Monitoring During Ischemia and Resuscitation.

Journal Article J Vis Exp · April 14, 2023 Most cardiac arrest (CA) survivors experience varying degrees of neurologic deficits. To understand the mechanisms that underpin CA-induced brain injury and, subsequently, develop effective treatments, experimental CA research is essential. To this end, a ... Full text Link to item Cite

Photoacoustic imaging with limited sampling: a review of machine learning approaches.

Journal Article Biomedical optics express · April 2023 Photoacoustic imaging combines high optical absorption contrast and deep acoustic penetration, and can reveal structural, molecular, and functional information about biological tissue non-invasively. Due to practical restrictions, photoacoustic imaging sys ... Full text Cite

Sustained overexpression of spliced X-box-binding protein-1 in neurons leads to spontaneous seizures and sudden death in mice.

Journal Article Commun Biol · March 9, 2023 The underlying etiologies of seizures are highly heterogeneous and remain incompletely understood. While studying the unfolded protein response (UPR) pathways in the brain, we unexpectedly discovered that transgenic mice (XBP1s-TG) expressing spliced X-box ... Full text Link to item Cite

Dissimilar cavitation dynamics and damage patterns produced by parallel fiber alignment to the stone surface in holmium:yttrium aluminum garnet laser lithotripsy.

Journal Article Physics of fluids (Woodbury, N.Y. : 1994) · March 2023 Recent studies indicate that cavitation may play a vital role in laser lithotripsy. However, the underlying bubble dynamics and associated damage mechanisms are largely unknown. In this study, we use ultra-high-speed shadowgraph imaging, hydrophone measure ... Full text Cite

Plasmonic nanorod probes' journey inside plant cells for in vivo SERS sensing and multimodal imaging.

Journal Article Nanoscale · March 2023 Nanoparticle-based platforms are gaining strong interest in plant biology and bioenergy research to monitor and control biological processes in whole plants. However, in vivo monitoring of biomolecules using nanoparticles inside plant cells remains ... Full text Cite

High-Speed Photoacoustic Microscopy Captures Processes Within Tissue

Journal Article Biophotonics International · March 1, 2023 When Alexander Graham Bell discovered the photoacoustic effect in the 1880s, he might not have envisioned that this technology would ultimately be successfully implemented in biomedical imaging applications such as neuroscience, dermatology, and cancer bio ... Cite

Three-dimensional non-invasive brain imaging of ischemic stroke by integrated photoacoustic, ultrasound and angiographic tomography (PAUSAT).

Journal Article Photoacoustics · February 2023 We present an ischemic stroke study using our newly-developed PAUSAT system that integrates photoacoustic computed tomography (PACT), high-frequency ultrasound imaging, and acoustic angiographic tomography. PAUSAT is capable of three-dimensional (3D) imagi ... Full text Link to item Cite

High-fidelity deep functional photoacoustic tomography enhanced by virtual point sources.

Journal Article Photoacoustics · February 2023 Photoacoustic tomography (PAT), a hybrid imaging modality that acoustically detects the optical absorption contrast, is a promising technology for imaging hemodynamic functions in deep tissues far beyond the traditional optical microscopy. However, the mos ... Full text Cite

Deep-tissue SWIR imaging using rationally designed small red-shifted near-infrared fluorescent protein.

Journal Article Nat Methods · January 2023 Applying rational design, we developed 17 kDa cyanobacteriochrome-based near-infrared (NIR-I) fluorescent protein, miRFP718nano. miRFP718nano efficiently binds endogenous biliverdin chromophore and brightly fluoresces in mammalian cells and tissues. miRFP7 ... Full text Open Access Link to item Cite

SwinIR for Photoacoustic Computed Tomography Artifact Reduction

Conference IEEE International Ultrasonics Symposium, IUS · January 1, 2023 Photoacoustic (PA) imaging is an emerging hybrid medical imaging modality involving the optical excitation of chromophores - light-sensitive molecules like hemoglobin and lipids, to infer underlying vascular structure. Supplying them energy in the form of ... Full text Cite

Intraperitoneal administration for sustained photoacoustic contrast agent imaging.

Journal Article Photoacoustics · December 2022 Photoacoustic (PA) imaging at 1064 nm in the second near-infrared (NIR-II) has attracted recent attention. We recently reported a surfactant-based formulation of a NIR-II dye (BIBDAH) for NIR-II PA contrast. Here, we investigated BIBDAH as a NIR-II PA cont ... Full text Cite

High-speed wide-field photoacoustic microscopy using a cylindrically focused transparent high-frequency ultrasound transducer.

Journal Article Photoacoustics · December 2022 Combining focused optical excitation and high-frequency ultrasound detection, optical-resolution photoacoustic microscopy (OR-PAM) can provide micrometer-level spatial resolution with millimeter-level penetration depth and has been employed in a variety of ... Full text Link to item Cite

Glassfrogs conceal blood in their liver to maintain transparency.

Journal Article Science (New York, N.Y.) · December 2022 Transparency in animals is a complex form of camouflage involving mechanisms that reduce light scattering and absorption throughout the organism. In vertebrates, attaining transparency is difficult because their circulatory system is full of red blood cell ... Full text Cite

Three-Dimensional Deep-Tissue Functional and Molecular Imaging by Integrated Photoacoustic, Ultrasound, and Angiographic Tomography (PAUSAT).

Journal Article IEEE Trans Med Imaging · October 2022 Featured Publication Non-invasive small-animal imaging technologies, such as optical imaging, magnetic resonance imaging and x -ray computed tomography, have enabled researchers to study normal biological phenomena or disease progression in their native conditions. However, ex ... Full text Link to item Cite

Multiscale photoacoustic tomography of neural activities with GCaMP calcium indicators.

Journal Article Journal of biomedical optics · September 2022 SignificanceOptical 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 diffus ... Full text Cite

The Effects of Scanning Speed and Standoff Distance of the Fiber on Dusting Efficiency during Short Pulse Holmium: YAG Laser Lithotripsy.

Journal Article J Clin Med · August 28, 2022 Featured Publication To investigate the effects of fiber lateral scanning speed across the stone surface (vfiber) and fiber standoff distance (SD) on dusting efficiency during short pulse holmium (Ho): YAG laser lithotripsy (LL), pre-soaked BegoStone samples were treated in wa ... Full text Link to item Cite

Real-time whole-brain imaging of hemodynamics and oxygenation at micro-vessel resolution with ultrafast wide-field photoacoustic microscopy.

Journal Article Light Sci Appl · May 17, 2022 High-speed high-resolution imaging of the whole-brain hemodynamics is critically important to facilitating neurovascular research. High imaging speed and image quality are crucial to visualizing real-time hemodynamics in complex brain vascular networks, an ... Full text Open Access Link to item Cite

Deep-E: A Fully-Dense Neural Network for Improving the Elevation Resolution in Linear-Array-Based Photoacoustic Tomography.

Journal Article IEEE transactions on medical imaging · May 2022 Featured Publication Linear-array-based photoacoustic tomography has shown broad applications in biomedical research and preclinical imaging. However, the elevational resolution of a linear array is fundamentally limited due to the weak cylindrical focus of the transducer elem ... Full text Cite

Deep thrombosis characterization using photoacoustic imaging with intravascular light delivery.

Journal Article Biomedical engineering letters · May 2022 Featured Publication Venous thromboembolism (VTE) is a condition in which blood clots form within the deep veins of the leg or pelvis to cause deep vein thrombosis. The optimal treatment of VTE is determined by thrombus properties such as the age, size, and chemical compositio ... Full text Cite

Optogenetic manipulation and photoacoustic imaging using a near-infrared transgenic mouse model.

Journal Article Nature communications · May 2022 Featured Publication Optogenetic manipulation and optical imaging in the near-infrared range allow non-invasive light-control and readout of cellular and organismal processes in deep tissues in vivo. Here, we exploit the advantages of Rhodopseudomonas palustris BphP1 bacterial ... Full text Cite

Detection of weak optical absorption by optical-resolution photoacoustic microscopy.

Journal Article Photoacoustics · March 2022 Featured Publication Optical-resolution photoacoustic microscopy (OR-PAM) is one of the major implementations of photoacoustic (PA) imaging. With tightly focused optical illumination and high-frequency ultrasound detection, OR-PAM provides micrometer-level resolutions as well ... Full text Cite

Photoacoustic imaging of 3D-printed vascular networks.

Journal Article Biofabrication · January 2022 Thrombosis in the circulation system can lead to major myocardial infarction and cardiovascular deaths. Understanding thrombosis formation is necessary for developing safe and effective treatments. In this work, using digital light processing (DLP)-based 3 ... Full text Cite

Editorial: Advances in Photoacoustic Neuroimaging.

Journal Article Frontiers in neuroscience · January 2022 Featured Publication Full text Cite

Sound out the impaired perfusion: Photoacoustic imaging in preclinical ischemic stroke.

Journal Article Front Neurosci · 2022 Acoustically detecting the optical absorption contrast, photoacoustic imaging (PAI) is a highly versatile imaging modality that can provide anatomical, functional, molecular, and metabolic information of biological tissues. PAI is highly scalable and can p ... Full text Link to item Cite

High-Frequency 3D Photoacoustic Computed Tomography Using an Optical Microring Resonator.

Journal Article BME frontiers · January 2022 3D photoacoustic computed tomography (3D-PACT) has made great advances in volumetric imaging of biological tissues, with high spatial-temporal resolutions and large penetration depth. The development of 3D-PACT requires high-performance acoustic sensors wi ... Full text Cite

Tumour classification with optimized sliding window size for OCT imaging

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2022 Skin and subcutaneous tumors are widespread in dogs and cats. Current tumor diagnostics (e.g., biopsy, fine-needle cytology) is invasive and labor-consuming. In this work, we studied ex vivo the most common canine and feline tumor OCT images using sliding ... Full text Cite

High-speed functional photoacoustic microscopy using a water-immersible two-axis torsion-bending scanner.

Journal Article Photoacoustics · December 2021 Optical-resolution photoacoustic microscopy (OR-PAM) can provide functional, anatomical, and molecular images at micrometer level resolution with an imaging depth of less than 1 mm in tissue. However, the imaging speed of traditional OR-PAM is often low du ... Full text Link to item Cite

Photoacoustic computed tomography of mechanical HIFU-induced vascular injury.

Journal Article Biomedical optics express · September 2021 Mechanical high-intensity focused ultrasound (HIFU) has been used for cancer treatment and drug delivery. Existing monitoring methods for mechanical HIFU therapies such as MRI and ultrasound imaging often suffer from high cost, poor spatial-temporal resolu ... Full text Cite

Seeing through the Skin: Photoacoustic Tomography of Skin Vasculature and Beyond.

Journal Article JID innovations : skin science from molecules to population health · September 2021 Skin diseases are the most common human diseases and manifest in distinct structural and functional changes to skin tissue components such as basal cells, vasculature, and pigmentation. Although biopsy is the standard practice for skin disease diagnosis, i ... Full text Cite

Handheld bioprinting strategies for in situ wound dressing.

Journal Article Essays in biochemistry · August 2021 Handheld bioprinting has recently attracted considerable attention as a technology to deliver biomaterials and/or cells to injury sites by using freeform, user-instructed deposition approaches, specifically targeted towards in situ wound dressing and heali ... Full text Cite

Time-Resolved Passive Cavitation Mapping Using the Transient Angular Spectrum Approach.

Journal Article IEEE transactions on ultrasonics, ferroelectrics, and frequency control · July 2021 Featured Publication Passive cavitation mapping (PCM), which generates images using bubble acoustic emission signals, has been increasingly used for monitoring and guiding focused ultrasound surgery (FUS). PCM can be used as an adjunct to magnetic resonance imaging to provide ... Full text Cite

Photoacoustic imaging of in vivo hemodynamic responses to sodium nitroprusside.

Journal Article J Biophotonics · July 2021 Featured Publication The in vivo hemodynamic impact of sodium nitroprusside (SNP), a widely used antihypertensive agent, has not been well studied. Here, we applied functional optical-resolution photoacoustic microscopy (OR-PAM) to study the hemodynamic responses to SNP in mic ... Full text Open Access Link to item Cite

Structural and Functional Imaging of the Retina in Central Retinal Artery Occlusion - Current Approaches and Future Directions.

Journal Article J Stroke Cerebrovasc Dis · July 2021 Central retinal artery occlusion (CRAO) is a form of acute ischemic stroke which affects the retina. Intravenous thrombolysis is emerging as a compelling therapeutic approach. However, it is not known which patients may benefit from this therapy because th ... Full text Link to item Cite

Translational Photoacoustic Imaging for Disease Diagnosis, Monitoring, and Surgical Guidance: introduction to the feature issue.

Journal Article Biomedical optics express · July 2021 This feature issue of Biomedical Optics Express covered all aspects of translational photoacoustic research. Application areas include screening and diagnosis of diseases, imaging of disease progression and therapeutic response, and image-guided tre ... Full text Cite

Deep image prior for undersampling high-speed photoacoustic microscopy.

Journal Article Photoacoustics · June 2021 Photoacoustic microscopy (PAM) is an emerging imaging method combining light and sound. However, limited by the laser's repetition rate, state-of-the-art high-speed PAM technology often sacrifices spatial sampling density (i.e., undersampling) for i ... Full text Cite

Sounding out the hidden data: A concise review of deep learning in photoacoustic imaging.

Journal Article Experimental biology and medicine (Maywood, N.J.) · June 2021 The rapidly evolving field of photoacoustic tomography utilizes endogenous chromophores to extract both functional and structural information from deep within tissues. It is this power to perform precise quantitative measurements in vivo-with endoge ... Full text Cite

Deep image prior for undersampling high-speed photoacoustic microscopy

Journal Article Photoacoustics · June 1, 2021 Photoacoustic microscopy (PAM) is an emerging imaging method combining light and sound. However, limited by the laser's repetition rate, state-of-the-art high-speed PAM technology often sacrifices spatial sampling density (i.e., undersampling) for increase ... Full text Cite

Perspective on fast-evolving photoacoustic tomography.

Journal Article Journal of biomedical optics · June 2021 SignificanceAcoustically 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 scal ... Full text Cite

Instant Ultrasound-Evoked Precise Nanobubble Explosion and Deep Photodynamic Therapy for Tumors Guided by Molecular Imaging.

Journal Article ACS applied materials & interfaces · May 2021 Nanobubbles (NBs) have recently gained interest in cancer imaging and therapy due to the fact that nanoparticles with the size range of 1-1000 nm can extravasate into permeable tumor types through the enhanced permeability and retention (EPR) effect. Howev ... Full text Cite

A near-infrared genetically encoded calcium indicator for in vivo imaging.

Journal Article Nat Biotechnol · March 2021 While calcium imaging has become a mainstay of modern neuroscience, the spectral properties of current fluorescent calcium indicators limit deep-tissue imaging as well as simultaneous use with other probes. Using two monomeric near-infrared (NIR) fluoresce ... Full text Link to item Cite

3D Monte Carlo simulation of light distribution in mouse brain in quantitative photoacoustic computed tomography.

Journal Article Quantitative imaging in medicine and surgery · March 2021 Featured Publication BackgroundPhotoacoustic computed tomography (PACT) detects light-induced ultrasound (US) waves to reconstruct the optical absorption contrast of the biological tissues. Due to its relatively deep penetration (several centimeters in soft tissue), h ... Full text Cite

Acoustic impact of the human skull on transcranial photoacoustic imaging.

Journal Article Biomedical optics express · March 2021 With balanced spatial resolution, imaging depth, and functional sensitivity, photoacoustic tomography (PAT) hold great promise for human brain imaging. However, the strong acoustic attenuation and aberration of the human skull (∼8 mm thick) are longstandin ... Full text Cite

Reconstructing Undersampled Photoacoustic Microscopy Images Using Deep Learning.

Journal Article IEEE transactions on medical imaging · February 2021 Featured Publication One primary technical challenge in photoacoustic microscopy (PAM) is the necessary compromise between spatial resolution and imaging speed. In this study, we propose a novel application of deep learning principles to reconstruct undersampled PAM images and ... Full text Cite

Tri-modality cavitation mapping in shock wave lithotripsy.

Journal Article The Journal of the Acoustical Society of America · February 2021 Featured Publication Shock wave lithotripsy (SWL) has been widely used for non-invasive treatment of kidney stones. Cavitation plays an important role in stone fragmentation, yet it may also contribute to renal injury during SWL. It is therefore crucial to determine the spatio ... Full text Cite

Internal-Illumination Photoacoustic Tomography Enhanced by a Graded-Scattering Fiber Diffuser.

Journal Article IEEE transactions on medical imaging · January 2021 Featured Publication The penetration depth of photoacoustic imaging in biological tissues has been fundamentally limited by the strong optical attenuation when light is delivered externally through the tissue surface. To address this issue, we previously reported internal-illu ... Full text Cite

Reconstructing Undersampled Photoacoustic Microscopy Images Using Deep Learning.

Journal Article IEEE Trans. Medical Imaging · 2021 Featured Publication Full text Cite

Photoacoustic Molecular Imaging: Principles and Practice

Chapter · January 1, 2021 Physically combining optical excitation and acoustic detection, photoacoustic (PA) tomography (PAT) has become increasingly popular in biomedical research. By analyzing the optical absorption signature of the target, PAT can image various endogenous and ex ... Full text Cite

Fiber based laser ultrasound transducer for intravascular thrombolysis with detective photoacoustic imaging

Conference IEEE International Ultrasonics Symposium, IUS · September 7, 2020 Featured Publication Ultrasound-enhanced thrombolysis, or sonothrombolysis, has been actively investigated due to its relatively high efficiency and better safeness compared with traditional thrombolysis methods such as mechanical thrombectomy and pharmaceutical treatment. Mos ... Full text Cite

Ultrasfast Wide-field Photoacoustic Microscopy of Small-animal Models

Conference 2020 IEEE Photonics Conference, IPC 2020 - Proceedings · September 1, 2020 Featured Publication We present our recent progress on a super-fast photoacoustic microscopy with an ultra-wide field of view. By using a novel polygon mirror scanner that can be immersed in water, we have achieved a B-scan frame rate of 2000 Hz with a scanning range of at lea ... Full text Cite

Internal-Illumination Photoacoustic Tomography Enhanced by a Graded-scattering Fiber Diffuser

Conference 2020 IEEE Photonics Conference, IPC 2020 - Proceedings · September 1, 2020 Featured Publication We developed a new low-cost fiber diffuser based on a graded-scattering method and uniform light emission was achieved by performing numerical simulations on several key design parameters. Proof-of-concept studies on phantoms and swine model have demonstra ... Full text Cite

Abstract 5243: Averting tumor growth in rodent breast cancer models with a liquid ablation approach

Conference Cancer Research · August 15, 2020 AbstractIn low-resource settings, surgery or radiation are inaccessible to 90% of cancer patients due to inadequate infrastructure and lack of trained personnel. Resource appropriate technologies must be dev ... Full text Cite

A generative adversarial network for artifact removal in photoacoustic computed tomography with a linear-array transducer.

Journal Article Experimental biology and medicine (Maywood, N.J.) · April 2020 Featured Publication Full text Cite

Snapshot Photoacoustic Topography Through an Ergodic Relay for High-throughput Imaging of Optical Absorption.

Journal Article Nature photonics · March 2020 Featured Publication 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 t ... Full text Cite

Simultaneous Photoacoustic Imaging and Cavitation Mapping in Shockwave Lithotripsy.

Journal Article IEEE transactions on medical imaging · February 2020 Featured Publication Kidney stone disease is a major health problem worldwide. Shockwave lithotripsy (SWL), which uses high-energy shockwave pulses to break up kidney stones, is extensively used in clinic. However, despite its noninvasiveness, SWL can produce cavitation in viv ... Full text Cite

EGFR in enterocytes & endothelium and HIF1α in enterocytes are dispensable for massive small bowel resection induced angiogenesis.

Journal Article PloS one · January 2020 Featured Publication BackgroundShort 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, ... Full text Cite

From Light to Sound: Photoacoustic and Ultrasound Imaging in Fundamental Research of Alzheimer's Disease.

Journal Article OBM neurobiology · January 2020 Featured Publication Alzheimer's disease (AD) causes severe cognitive dysfunction and has long been studied for the underlining physiological and pathological mechanisms. Several biomedical imaging modalities have been applied, including MRI, PET, and high-resolution optical m ... Full text Cite

Sound Out the Deep Colors: Photoacoustic Molecular Imaging at New Depths.

Journal Article Molecular imaging · January 2020 Photoacoustic tomography (PAT) has become increasingly popular for molecular imaging due to its unique optical absorption contrast, high spatial resolution, deep imaging depth, and high imaging speed. Yet, the strong optical attenuation of biological tissu ... Full text Cite

Photoacoustic Tomography of Neural Systems

Chapter · January 1, 2020 Neuroscience has become one of the most exciting contemporary research areas with major breakthroughs expected in the coming decades. Modern imaging techniques have enabled scientific understanding of the neural system by revealing anatomical, functional, ... Full text Cite

Photoacoustic imaging of skin

Chapter · November 27, 2019 Photoacoustic tomography (PAT) is an emerging optical imaging modality with high spatial and temporal resolutions, deep penetration, and rich optical absorption contrast. Since the first demonstration of functional photoacoustic imaging in 2003, the last d ... Full text Cite

Listening to tissues with new light: recent technological advances in photoacoustic imaging.

Journal Article Journal of optics (2010) · October 2019 Featured Publication Photoacoustic tomography (PAT), or optoacoustic tomography, has achieved remarkable progress in the past decade, benefiting from the joint developments in optics, acoustics, chemistry, computing and mathematics. Unlike pure optical or ultrasound imaging, P ... Full text Cite

Simultaneous photoacoustic imaging of intravascular and tissue oxygenation.

Journal Article Optics letters · August 2019 Featured Publication Hypoxia, a low tissue oxygenation condition caused by insufficient oxygen supply, leads to potentially irreversible tissue damage, such as brain infarction during stroke. Intravascular oxygenation has long been used by photoacoustic imaging, among other im ... Full text Cite

Impacts of the murine skull on high-frequency transcranial photoacoustic brain imaging.

Journal Article Journal of biophotonics · July 2019 Featured Publication Non-invasive photoacoustic tomography (PAT) of mouse brains with intact skulls has been a challenge due to the skull's strong acoustic attenuation, aberration, and reverberation, especially in the high-frequency range (>15 MHz). In this paper, we systemati ... Full text Cite

Fiber-optic laser-ultrasound transducer using carbon nanoparticles for intravascular sonothrombolysis

Conference Proceedings of the IEEE Conference on Nanotechnology · July 1, 2019 Intravascular ultrasound thrombolysis has shown its advantages in the improved treatment rate compared with traditional administration of thrombolytic agents, and a safer treatment procedure compared with mechanical drilling methods. However, the method st ... Full text Cite

Imaging the aged brain: pertinence and methods.

Journal Article Quantitative imaging in medicine and surgery · May 2019 Featured Publication The global population is ageing at an accelerating speed. The ability to perform working memory tasks together with rapid processing becomes increasingly difficult with increases in age. With increasing national average life spans and a rise in the prevale ... Full text Cite

Photoacoustic imaging of skin

Chapter · April 24, 2019 Photoacoustic tomography (PAT) is an emerging optical imaging modality with high spatial and temporal resolutions, deep penetration, and rich optical absorption contrast. Since the first demonstration of functional photoacoustic imaging in 2003, the last d ... Cite

Thermal Memory Based Photoacoustic Imaging of Temperature.

Journal Article Optica · February 2019 Featured Publication Temperature mapping is essential in many biomedical studies and interventions to precisely control the tissue's thermal conditions for optimal treatment efficiency and minimal side effects. Based on the Grüneisen parameter's temperature dependence, photoac ... Full text Cite

In vivo photoacoustic multi-contrast imaging and detection of protein interactions using a small near-infrared photochromic protein

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019 Photoacoustic (PA) computed tomography (PACT) is a non-invasive imaging technique offering optical contrast, high resolution, and deep penetration in biological tissues. PACT, highly sensitive to optical absorption by molecules, is inherently suited for mo ... Full text Cite

Application of mathematical morphological filter for noise reduction in photoacoustic imaging

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019 Photoacoustic imaging (PAI) is a promising imaging technique in preclinical study, which combines both merits of optical and ultrasound imaging. However, PA image quality is seriously suffered from various noises such as random white noise, intrinsic noise ... Full text Cite

High-speed widefield photoacoustic microscopy of small-animal hemodynamics.

Journal Article Biomed Opt Express · October 1, 2018 Featured Publication Optical-resolution photoacoustic microscopy (OR-PAM) has become a popular tool in small-animal hemodynamic studies. However, previous OR-PAM techniques variously lacked a high imaging speed and/or a large field of view, impeding the study of highly dynamic ... Full text Open Access Link to item Cite

Dual-view acoustic-resolution photoacoustic microscopy with enhanced resolution isotropy.

Journal Article Optics letters · September 2018 Featured Publication Acoustic-resolution photoacoustic microscopy (AR-PAM) can provide penetration depths beyond the optical diffusion limit, but its lateral resolution is typically much worse than its axial resolution, resulting in a low-resolution isotropy. We herein present ... Full text Cite

Advances in super-resolution photoacoustic imaging.

Journal Article Quantitative imaging in medicine and surgery · September 2018 Featured Publication Full text Cite

Concurrent photoacoustic and ultrasound microscopy with a coaxial dual-element ultrasonic transducer.

Journal Article Visual computing for industry, biomedicine, and art · September 2018 Simultaneous photoacoustic and ultrasound (PAUS) imaging has attracted increasing attention in biomedical research to probe the optical and mechanical properties of tissue. However, the resolution for majority of the existing PAUS systems is on the order o ... Full text Cite

Recent progress in photoacoustic molecular imaging.

Journal Article Current opinion in chemical biology · August 2018 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 iden ... Full text Cite

Quad-mode functional and molecular photoacoustic microscopy.

Journal Article Scientific reports · July 2018 Featured Publication A conventional photoacoustic microscopy (PAM) system typically has to make tradeoffs between its spatial resolution and penetration depth, by choosing a fixed configuration of optical excitation and acoustic detection. The single-scale imaging capability o ... Full text Cite

Small near-infrared photochromic protein for photoacoustic multi-contrast imaging and detection of protein interactions in vivo.

Journal Article Nature communications · July 2018 Featured Publication 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 bac ... Full text Cite

Photoacoustic tomography of blood oxygenation: A mini review.

Journal Article Photoacoustics · June 2018 Photoacoustic tomography (PAT) is a hybrid imaging modality that combines rich contrast of optical excitation and deep penetration of ultrasound detection. With its unique optical absorption contrast mechanism, PAT is inherently sensitive to the functional ... Full text Cite

Photoacoustic microscopy: principles and biomedical applications.

Journal Article Biomedical engineering letters · May 2018 Photoacoustic microscopy (PAM) has become an increasingly popular technology for biomedical applications, providing anatomical, functional, and molecular information. In this concise review, we first introduce the basic principles and typical system design ... Full text Cite

Imaging Biomaterial-Tissue Interactions.

Journal Article Trends in biotechnology · April 2018 Modern biomedical imaging has revolutionized life science by providing anatomical, functional, and molecular information of biological species with high spatial resolution, deep penetration, enhanced temporal responsiveness, and improved chemical specifici ... Full text Cite

Dichroism-sensitive photoacoustic computed tomography.

Journal Article Optica · April 2018 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 bi ... Full text Cite

Internal-illumination photoacoustic computed tomography.

Journal Article Journal of biomedical optics · March 2018 We report a photoacoustic computed tomography (PACT) system using a customized optical fiber with a cylindrical diffuser to internally illuminate deep targets. The traditional external light illumination in PACT usually limits the penetration depth to a fe ... Full text Cite

Correcting the limited view in optical-resolution photoacoustic microscopy.

Journal Article Journal of biophotonics · February 2018 Featured Publication 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 ... Full text Cite

Deep-tissue temperature mapping by multi-illumination photoacoustic tomography aided by a diffusion optical model: a numerical study.

Journal Article Journal of biomedical optics · January 2018 Temperature mapping during thermotherapy can help precisely control the heating process, both temporally and spatially, to efficiently kill the tumor cells and prevent the healthy tissues from heating damage. Photoacoustic tomography (PAT) has been used fo ... Full text Cite

High-speed wide-field photoacoustic microscopy

Conference Optics InfoBase Conference Papers · January 1, 2018 We present our recent progress on a super-fast photoacoustic microscopy with an ultrawide field of view. By using a novel polygon mirror scanner that can be immersed in water, we have achieved a B-scan frame rate of 1000 Hz with a scanning range of at leas ... Full text Cite

From bench to market: commercialization of photoacoustic imaging

Journal Article Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering · November 25, 2017 Photoacoustic imaging (PAI) or optoacoustic imaging, the modern application of an ancient physical discovery to biomedical imaging, is without doubt one of the most exciting imaging technologies that has drawn increasing attention from biomedical specialis ... Full text Cite

Wide-field fast-scanning photoacoustic microscopy of brain functions in action

Conference 2017 Conference on Lasers and Electro-Optics, CLEO 2017 - Proceedings · October 25, 2017 We have developed fast functional photoacoustic microscopy for 3D high- resolution high-speed imaging of the mouse brain. In particular, a novel single-wavelength pulse- width-based method can image blood oxygenation with capillary-level resolution at 100 ... Full text Cite

Photoacoustic thermal flowmetry with a single light source.

Journal Article Journal of biomedical optics · September 2017 Featured Publication We report a photoacoustic thermal flowmetry based on optical-resolution photoacoustic microscopy (OR-PAM) using a single laser source for both thermal tagging and photoacoustic excitation. When an optically absorbing medium is flowing across the optical fo ... Full text Cite

Photoacoustic imaging using genetically encoded reporters: a review.

Journal Article Journal of biomedical optics · July 2017 Featured Publication Genetically encoded contrast in photoacoustic imaging (PAI) is complementary to the intrinsic contrast provided by endogenous absorbing chromophores such as hemoglobin. The use of reporter genes expressing absorbing proteins opens the possibility of visual ... Full text Cite

High-speed photoacoustic microscopy of mouse cortical microhemodynamics.

Journal Article Journal of biophotonics · June 2017 We applied high-speed photoacoustic microscopy (PAM) for both cortical microenvironment studies and dynamic brain studies, with micrometer-level optical resolution and a millisecond-level cross-sectional imaging speed over a millimeter-level field of view. ... Full text Cite

When pressure meets light: detecting the photoacoustic effect at the origin.

Journal Article Light, science & applications · June 2017 Featured Publication Full text Cite

Handheld optical-resolution photoacoustic microscopy.

Journal Article Journal of biomedical optics · April 2017 Optical-resolution photoacoustic microscopy (OR-PAM) offers label-free Full text Cite

Direct measurement of hypoxia in a xenograft multiple myeloma model by optical-resolution photoacoustic microscopy.

Journal Article Cancer biology & therapy · February 2017 Using photoacoustic microscopy (PAM), we evaluated non-invasively oxygenation and vascularization in vivo due to multiple myeloma (MM) progression. Mice injected with MM.1S-GFP were monitored with a fluorescence microscope for tumor progression. In vivo PA ... Full text Cite

Real-time photoacoustic flow cytography and photothermolysis of single circulating melanoma cells in vivo

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2017 Metastasis is responsible for as many as 90% of cancer-related deaths, and the deadliest skin cancer, melanoma, has a high propensity for metastasis. Since hematogenous spread of circulating tumor cells (CTCs) is cancer's main route of metastasis, detectin ... Full text Cite

Imaging small animal whole-body dynamics by single-impulse panoramic photoacoustic computed tomography

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2017 Small animal whole-body imaging, providing physiological, pathological, and phenotypical insights into biological processes, is indispensable in preclinical research. With high spatiotemporal resolution and functional contrast, small animal imaging can vis ... Full text Cite

Single-impulse Panoramic Photoacoustic Computed Tomography of Small-animal Whole-body Dynamics at High Spatiotemporal Resolution.

Journal Article Nature biomedical engineering · January 2017 Featured Publication 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 ( ... Full text Cite

Photoacoustic neuroimaging

Chapter · January 1, 2017 The photoacoustic effect, first discovered by Alexander Bell in 1880 (Bell 1880), refers to the formation of sound waves following light absorption in an object. The conversion of optical energy to acoustic energy allows visualization of deep tissue optica ... Full text Cite

In vivo label-free photoacoustic flow cytography and on-the-spot laser killing of single circulating melanoma cells.

Journal Article Scientific reports · December 2016 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 cell ... Full text Cite

A practical guide to photoacoustic tomography in the life sciences.

Journal Article Nature methods · July 2016 Featured Publication 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 imag ... Full text Open Access Cite

Tutorial on photoacoustic tomography.

Journal Article Journal of biomedical optics · June 2016 Featured Publication 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 h ... Full text Cite

In vivo photoacoustic tomography of myoglobin oxygen saturation.

Journal Article Journal of biomedical optics · June 2016 Featured Publication Myoglobin is an essential oxygen-binding hemoprotein in skeletal and cardiac muscles that buffers intracellular oxygen (O2) concentration in response to hypoxia or elevated muscle activities. We present a method that uses photoacoustic computed tomography ... Full text Cite

Photoacoustic elastography.

Journal Article Optics letters · February 2016 Featured Publication 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 ... Full text Cite

Multiscale photoacoustic tomography using reversibly switchable bacterial phytochrome as a near-infrared photochromic probe.

Journal Article Nature methods · January 2016 Featured Publication 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 ... Full text Open Access Cite

Multiscale Functional and Molecular Photoacoustic Tomography.

Journal Article Ultrasonic imaging · January 2016 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 orga ... Full text Cite

Reversibly switchable photoacoustic tomography using a genetically encoded near-infrared phytochrome

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2016 Optical imaging of genetically encoded probes has revolutionized biomedical studies by providing valuable information about targeted biological processes. Here, we report a novel imaging technique, termed reversibly switchable photoacoustic tomography (RS- ... Full text Cite

Nanoparticles for photoacoustic imaging of vasculature

Chapter · January 1, 2016 Photoacoustic imaging (PAI) is a multi-scale, multi-contrast biomedical imaging modality that can provide anatomical, functional, metabolic, and molecular information about tissue. PAI offers up to submicron resolution and several centimeters penetration d ... Full text Cite

High-speed label-free functional photoacoustic microscopy of mouse brain in action.

Journal Article Nature methods · May 2015 Featured Publication 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-dimens ... Full text Open Access Cite

Photoacoustic microscopy: superdepth, superresolution, and superb contrast.

Journal Article IEEE pulse · May 2015 Featured Publication 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 ... Full text Cite

Fast functional photoacoustic microscopy of mouse brain

Conference Optics and the Brain, BRAIN 2015 · April 6, 2015 We have developed fast functional photoacoustic microscopy (ffPAM). which can be utilized for three-dimensional morphological, functional, flow dynamic and metabolic mouse brain imaging through an intact skull with endogenous contrast only. ... Full text Cite

Photoacoustic imaging of single circulating melanoma cells in vivo

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · March 11, 2015 Melanoma, one of the most common types of skin cancer, has a high mortality rate, mainly due to a high propensity for tumor metastasis. The presence of circulating tumor cells (CTCs) is a potential predictor for metastasis. Label-free imaging of single cir ... Full text Cite

Photo-imprint super-resolution photoacoustic microscopy

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · March 11, 2015 Combining the absorption-based photoacoustic effect and intensity-dependent photobleaching effect, we demonstrate a simple method for super-resolution photoacoustic imaging of both fluorescent and non-fluorescent samples. Our method is based on a double-ex ... Full text Cite

Label-free optical-resolution photoacoustic endomicroscopy in vivo

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · March 11, 2015 Intravital microscopy techniques have become increasingly important in biomedical research because they can provide unique microscopic views of various biological or disease developmental processes in situ. Here we present an optical-resolution photoacoust ... Full text Cite

Three-dimensional photoacoustic and ultrasonic endoscopic imaging of two rabbit esophagi

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · March 11, 2015 The addition of photoacoustic endoscopy to conventional endoscopic ultrasound offers imaging capabilities that may improve diagnosis and clinical care of gastrointestinal tract diseases. In this study, using a 3.8-mm diameter dual-mode photoacoustic and ul ... Full text Cite

Optical-resolution photoacoustic endomicroscopy in vivo.

Journal Article Biomedical optics express · March 2015 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 ... Full text Cite

Three-dimensional photoacoustic endoscopic imaging of the rabbit esophagus.

Journal Article PloS one · January 2015 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 ... Full text Cite

Fast functional photoacoustic microscopy of mouse brain

Conference Optics and the Brain, BRAIN 2015 · January 1, 2015 © OSA 2015. We have developed fast functional photoacoustic microscopy (ffPAM). which can be utilized for three-dimensional morphological, functional, flow dynamic and metabolic mouse brain imaging through an intact skull with endogenous contrast only. ... Cite

Photoacoustic lymphatic imaging with high spatial-temporal resolution.

Journal Article Journal of biomedical optics · November 2014 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 mo ... Full text Cite

Near-infrared optical-resolution photoacoustic microscopy.

Journal Article Optics letters · September 2014 Compared with visible light (380-700 nm), near-infrared light (700-1400 nm) undergoes weaker optical attenuation in biological tissue; thus, it can penetrate deeper. Herein, we demonstrate near-infrared optical-resolution photoacoustic microscopy (NIR-OR-P ... Full text Cite

Reversibly switchable fluorescence microscopy with enhanced resolution and image contrast.

Journal Article Journal of biomedical optics · August 2014 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 ... Full text Cite

Optical-resolution photoacoustic microscopy for volumetric and spectral analysis of histological and immunochemical samples.

Journal Article Angewandte Chemie (International ed. in English) · July 2014 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 chro ... Full text Cite

In vivo optically encoded photoacoustic flowgraphy.

Journal Article Optics letters · July 2014 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 enc ... Full text Cite

Sensitivity of photoacoustic microscopy.

Journal Article Photoacoustics · June 2014 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 broke ... Full text Cite

Photoacoustic Brain Imaging: from Microscopic to Macroscopic Scales.

Journal Article Neurophotonics · May 2014 Human brain mapping has become one of the most exciting contemporary research areas, with major breakthroughs expected in the following decades. Modern brain imaging techniques have allowed neuroscientists to gather a wealth of anatomic and functional info ... Full text Cite

Breakthrough in Photonics 2013: Photoacoustic Tomography in Biomedicine.

Journal Article IEEE photonics journal · April 2014 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 p ... Full text Cite

Calibration-free structured-illumination photoacoustic flowgraphy of transverse flow in scattering media.

Journal Article Journal of biomedical optics · April 2014 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 ... Full text Cite

Photoacoustic microscopy with enhanced resolution and imaging depth aided by optical clearing

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · March 3, 2014 Both the spatial resolution and maximum penetration depth of optical-resolution photoacoustic microscopy (ORPAM) deteriorate sharply with depth due to strong light scattering in tissue. To reduce tissue scattering, we propose to use glycerol as an optical ... Full text Cite

Calibration-free absolute quantification of particle concentration by statistical analyses of photoacoustic signals in vivo.

Journal Article Journal of biomedical optics · March 2014 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 analyzin ... Full text Cite

Photoacoustic tomography: principles and advances.

Journal Article Electromagnetic waves (Cambridge, Mass.) · January 2014 Featured Publication 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 chromophore ... Full text Open Access Cite

Fabrication of Cell Patches Using Biodegradable Scaffolds with a Hexagonal Array of Interconnected Pores (SHAIPs).

Journal Article Polymer · January 2014 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 patc ... Full text Cite

Photoimprint photoacoustic microscopy for three-dimensional label-free subdiffraction imaging.

Journal Article Physical review letters · January 2014 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 demo ... Full text Cite

Photoacoustic correlation spectroscopy for calibration-free absolute quantification of particle concentration

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014 Currently, laser fluence calibration is typically required for quantitative measurement of particle concentration in photoacoustic microscopy. In this paper, we present another quantitative approach to measure absolute absorber concentrations by photoacous ... Full text Cite

Photoacoustic Doppler axial flow measurement of homogenous media using structured illumination

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014 We propose time and frequency domain methods for homogenous flow measurement based on the photoacoustic Doppler effect. Excited by spatially modulated laser pulses, the flowing medium induces a Doppler frequency shift in the received photoacoustic signals. ... Full text Cite

Multi-parametric quantitative microvascular imaging with optical-resolution photoacoustic microscopy in vivo.

Conference Optics express · January 2014 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 m ... Full text Cite

Non-invasive and in situ characterization of the degradation of biomaterial scaffolds by volumetric photoacoustic microscopy.

Journal Article Angewandte Chemie (International ed. in English) · January 2014 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 ... Full text Cite

Absolute photoacoustic thermometry in deep tissue.

Journal Article Optics letters · December 2013 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 Grüneisen parameter and the speed of sound in tissue. By ... Full text Cite

Ultrasonically encoded photoacoustic flowgraphy in biological tissue.

Journal Article Physical review letters · November 2013 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 p ... Full text Cite

Ultrasound-heated photoacoustic flowmetry.

Journal Article Journal of biomedical optics · November 2013 Featured Publication 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. P ... Full text Cite

Photoacoustic Microscopy.

Journal Article Laser & photonics reviews · September 2013 Featured Publication 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 a ... Full text Cite

Structured-illumination photoacoustic Doppler flowmetry of axial flow in homogeneous scattering media.

Journal Article Applied physics letters · August 2013 Featured Publication 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. T ... Full text Cite

Optical clearing-aided photoacoustic microscopy with enhanced resolution and imaging depth.

Journal Article Optics letters · July 2013 Featured Publication 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 optica ... Full text Cite

A water-immersible 2-Axis scanning mirror microsystem for ultrasound and photoacoustic microscopic imaging applications

Conference Proceedings of SPIE - The International Society for Optical Engineering · June 12, 2013 For both ultrasound and photoacoustic microscopic imaging, a fast scanning ability is required, whereas the liquid environment for acoustic propagation limits the usage of traditional MEMS scanning mirrors. In this paper, a new waterimmersible scanning mir ... Full text Cite

Up-regulation of hypoxia-inducible factor 1 alpha and hemodynamic responses following massive small bowel resection.

Journal Article Journal of pediatric surgery · June 2013 Featured Publication PurposeMassive 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 (sO2) after SBR. We therefore sought to determine t ... Full text Cite

Photoacoustic microscopy of neovascularization in three-dimensional porous scaffolds

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 28, 2013 It is a challenge to non-invasively visualize in vivo the neovascularization in a three-dimensional (3D) scaffold with high spatial resolution and deep penetration depth. Here we used photoacoustic microscopy (PAM) to chronically monitor neovascularization ... Full text Cite

Noninvasive photoacoustic computed tomography of mouse brain metabolism in vivo

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 28, 2013 To control the overall action of the body, brain consumes a large amount of energy in proportion to its volume. In humans and many other species, the brain gets most of its energy from oxygen-dependent metabolism of glucose. An abnormal metabolic rate of g ... Full text Cite

Water-Immersible MEMS scanning mirror designed for wide-field fast-scanning photoacoustic microscopy

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 28, 2013 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 spe ... Full text Cite

Photoacoustic microscopy with 7.6-μm axial resolution

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · March 4, 2013 The axial resolution of photoacoustic microscopy (PAM) is much lower than its lateral resolution, which resolves down to the submicron level. Here we achieved so far the highest axial resolution of 7.6 μm by using a commercial 125 MHz ultrasonic transducer ... Full text Cite

Photoacoustic endoscopic imaging of the rabbit mediastinum

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · March 4, 2013 Like ultrasound endoscopy, photoacoustic endoscopy (PAE) could become a valuable addition to clinical practice due to its deep imaging capability. Results from our recent in vivo transesophageal endoscopic imaging study on rabbits demonstrate the technique ... Full text Cite

Investigation of neovascularization in three-dimensional porous scaffolds in vivo by a combination of multiscale photoacoustic microscopy and optical coherence tomography.

Journal Article Tissue engineering. Part C, Methods · March 2013 Featured Publication 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), includi ... Full text Cite

Noninvasive photoacoustic computed tomography of mouse brain metabolism in vivo.

Journal Article NeuroImage · January 2013 Featured Publication 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 stimulation ... Full text Cite

Multi-scale Multi-contrast Photoacoustic Microscopy

Conference Optics InfoBase Conference Papers · January 1, 2013 Photoacoustic microscopy (PAM) is a hybrid imaging technique that acoustically detects optical contrast via the photoacoustic effect. With its excellent scalability, PAM can simultaneously image anatomical, functional, molecular, flow dynamic, and metaboli ... Cite

A water-immersible 2-axis scanning mirror microsystem for ultrasound andha photoacoustic microscopic imaging applications.

Journal Article Microsystem technologies : sensors, actuators, systems integration · January 2013 Featured Publication 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 ... Full text Cite

Multi-scale Multi-contrast Photoacoustic Microscopy

Conference Optics InfoBase Conference Papers · January 1, 2013 Photoacoustic microscopy (PAM) is a hybrid imaging technique that acoustically detects optical contrast via the photoacoustic effect. With its excellent scalability, PAM can simultaneously image anatomical, functional, molecular, flow dynamic, and metaboli ... Full text Cite

Volumetric photoacoustic endoscopy

Conference Biomedical Optics, BIOMED 2012 · December 1, 2012 Photoacoustic endoscopy provides unique functional information through its broad spectroscopic imaging capability. The imaging results presented here suggest its potential for use as a comprehensive endoscopic tool in various medical applications. © 2012 O ... Cite

In vivo photoacoustic microscopy with 7.6-µm axial resolution using a commercial 125-MHz ultrasonic transducer.

Journal Article Journal of biomedical optics · November 2012 Featured Publication Photoacoustic microscopy has achieved submicron lateral resolution, but its axial resolution is much lower. Here an axial resolution of 7.6 μm, the highest axial resolution validated by experimental data, has been achieved by using a commercial 125 MHz ult ... Full text Cite

A 2.5-mm diameter probe for photoacoustic and ultrasonic endoscopy.

Journal Article Optics express · October 2012 Featured Publication 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 s ... Full text Cite

Wide-field fast-scanning photoacoustic microscopy based on a water-immersible MEMS scanning mirror.

Journal Article Journal of biomedical optics · August 2012 Featured Publication 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 spe ... Full text Cite

Simultaneous functional photoacoustic and ultrasonic endoscopy of internal organs in vivo.

Journal Article Nature medicine · August 2012 Featured Publication 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 ... Full text Cite

In vivo photoacoustic tomography of total blood flow and potential imaging of cancer angiogenesis and hypermetabolism.

Journal Article Technology in cancer research & treatment · August 2012 Featured Publication 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 ... Full text Cite

Immediate alterations in intestinal oxygen saturation and blood flow after massive small bowel resection as measured by photoacoustic microscopy.

Journal Article Journal of pediatric surgery · June 2012 Featured Publication PurposeMassive 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 o ... Full text Cite

Functional photoacoustic microscopy of diabetic vasculature.

Journal Article Journal of biomedical optics · June 2012 Featured Publication 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 pancr ... Full text Cite

Toward dual-wavelength functional photoacoustic endoscopy: Laser and peripheral optical systems development

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · April 9, 2012 Photoacoustic endoscopy (PAE) provides unique functional information with high spatial resolution at super depths. The provision of functional information is predicated on its strong spectroscopic imaging ability, and its deep imaging capability is derived ... Full text Cite

Multi-contrast photoacoustic microscopy

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · March 15, 2012 We developed multi-contrast photoacoustic microscopy (PAM) for in vivo anatomical, functional, metabolic, and molecular imaging. This technical innovation enables comprehensive understanding of the tumor microenvironment. With multi-contrast PAM, we longit ... Full text Cite

Double-illumination photoacoustic microscopy of intestinal hemodynamics following massive small bowel resection

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · February 23, 2012 Massive small bowel resection (SBR) results in villus angiogenesis and intestinal adaptation. The exact mechanism that causes intestinal villus angiogenesis remains unknown. We hypothesize that hemodynamic changes within the remnant bowel after SBR will tr ... Full text Cite

In vivo photoacoustic tomography of total blood flow and Doppler angle

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · February 23, 2012 As two hallmarks of cancer, angiogenesis and hypermetabolism are closely related to increased blood flow. Volumetric blood flow measurement is important to understanding the tumor microenvironment and developing new means to treat cancer. Current photoacou ... Full text Cite

Functional photoacoustic microscopy of pH

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · February 23, 2012 pH is a tightly regulated indicator of metabolic activity. In mammalian systems, imbalance of pH regulation may result from or result in serious illness. Even though the regulation system of pH is very robust, tissue pH can be altered in many diseases such ... Full text Cite

A 2.5-mm outer diameter photoacoustic endoscopic mini-probe based on a highly sensitive PMN-PT ultrasonic transducer

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · February 23, 2012 We have developed a 2.5-mm outer diameter photoacoustic endoscopic mini-probe to use in the instrument channel (typically 2.8 or 3.7 mm in diameter) of standard video endoscopes. To achieve adequate signal sensitivity, we fabricated a focused ultrasonic tr ... Full text Cite

Photoacoustic imaging of the near-infrared fluorescent protein iRFP in vivo

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · February 9, 2012 Genetically encoded probes powerfully and non-invasively target specific tissues, cells, and subcellular locations. iRFP, a novel near-infrared fluorescent protein with low quantum yield whose absorption and fluorescence maxima are located at wavelengths l ... Full text Cite

Double-illumination photoacoustic microscopy.

Journal Article Optics letters · February 2012 Featured Publication 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 ~1 mm in tissue, owing to the strong tissue scattering. Here, w ... Full text Cite

Deep-tissue photoacoustic tomography of a genetically encoded near-infrared fluorescent probe.

Journal Article Angewandte Chemie (International ed. in English) · February 2012 Featured Publication Full text Cite

In vivo imaging of epileptic activity using 2-NBDG, a fluorescent deoxyglucose analog.

Journal Article Journal of neuroscience methods · January 2012 Featured Publication 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-nitro ... Full text Cite

Water-Immersible MEMS scanning mirror enhanced optical-resolution photoacoustic microscopy

Conference Biomedical Optics, BIOMED 2012 · January 1, 2012 A fast scanning optical-resolution photoacoustic microscopy has been developed using a water-immersible MEMS mirror. A B-scan rate of 400 Hz over a 3 mm scanning range has been demonstrated in phantom studies. © OSA 2012. ... Full text Cite

Functional photoacoustic microscopy of pH.

Journal Article Journal of biomedical optics · October 2011 Featured Publication 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 fl ... Full text Cite

Photoacoustic tomography: fundamentals, advances and prospects.

Journal Article Contrast media & molecular imaging · September 2011 Featured Publication 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 ph ... Full text Cite

Photoacoustic microscopy of tyrosinase reporter gene in vivo.

Journal Article Journal of biomedical optics · August 2011 Featured Publication 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 indu ... Full text Cite

VEGF is essential for hypoxia-inducible factor-mediated neovascularization but dispensable for endothelial sprouting.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · August 2011 Featured Publication 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 (HI ... Full text Cite

Photoacoustic microscopy of microvascular responses to cortical electrical stimulation.

Journal Article Journal of biomedical optics · July 2011 Featured Publication 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 ... Full text Cite

Label-free oxygen-metabolic photoacoustic microscopy in vivo.

Journal Article Journal of biomedical optics · July 2011 Featured Publication 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 diseas ... Full text Cite

Conditional HIF-1 induction produces multistage neovascularization with stage-specific sensitivity to VEGFR inhibitors and myeloid cell independence.

Journal Article Blood · April 2011 Featured Publication 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 man ... Full text Cite

Photoacoustic microscopy of human teeth

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · March 31, 2011 Photoacoustic microscopy (PAM) utilizes short laser pulses to deposit energy into light absorbers and sensitively detects the ultrasonic waves the absorbers generate in response. PAM directly renders a three-dimensional spatial distribution of sub-surface ... Full text Cite

Noninvasive quantification of metabolic rate of oxygen (MRO2) by photoacoustic microscopy

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · February 17, 2011 Many diseases, normal decay and physiological functions are closely related to alterations in the metabolic rate of oxygen (MRO2). In this study, we demonstrate that all the parameters for MRO2 quantification can be simultaneously obtained by optical-resol ... Full text Cite

Tyrosinase-catalyzed melanin as a contrast agent for photoacoustic tomography

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · February 10, 2011 It is difficult to distinguish between tumor cells and surrounding cells without staining as is done in histology. We developed tyrosinase-catalyzed melanin as a reporter gene for photoacoustic tomography. Tyrosinase is the primary enzyme responsible for t ... Full text Cite

Effects of calibration factors and intensity dependent non-linearity on functional photoacoustic microscopy

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · February 10, 2011 Functional photoacoustic microscopy is a valuable tool in quantifying hemoglobin oxygenation within single vessels. In several functional studies with this tool, quantitative sO2 measurements were taken both in vitro and in vivo. Although in vitro measurem ... Full text Cite

Development of real-time photoacoustic microscopy

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · February 10, 2011 Photoacoustic tomography detecting ultrasound signals generated from photon absorption provides optical absorption contrast in vivo for structural, functional and molecular imaging. Although photoacoustic tomography technology has grown fast in recent year ... Full text Cite

Fast voice-coil scanning optical-resolution photoacoustic microscopy.

Journal Article Optics letters · January 2011 Featured Publication We developed a photoacoustic imaging system that has real-time imaging capability with optical resolution. The imaging system is capable of scanning at 20 Hz over a 9 mm range and up to 40 Hz over a 1 mm scanning range. A focused laser beam provides a late ... Full text Cite

In vivo photoacoustic mapping of lymphatic systems with plasmon-resonant nanostars.

Journal Article Journal of materials chemistry · January 2011 Featured Publication Plasmon-resonant nanostars (NSTs) provide excellent contrast enhancement for photoacoustic tomography. The high photoacoustic sensitivity of NSTs at near-infrared wavelengths enable their in vivo detection in rat sentinel lymph nodes and vessels, with dire ... Full text Cite

Transverse flow measurement using photoacoustic Doppler bandwidth broadening: Phantom and in vivo studies

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 3, 2010 In photoacoustic (PA) imaging of microvascular networks, the transverse component of the blood flow that is perpendicular to the acoustic probing beam is usually dominant. We propose a new method to measure the transverse flow, based on the Doppler bandwid ... Full text Cite

Optical-resolution photoacoustic microscopy of angiogenesis in a transgenic mouse model

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 3, 2010 A major obstacle in studying angiogenesis is the inability to noninvasively image neovascular development in an individual animal. We applied optical-resolution photoacoustic microscopy (OR-PAM) to determine the kinetics of hypoxia-inducible factor-1 (HIF- ... Full text Cite

In vivo photoacoustic imaging of transverse blood flow by using Doppler broadening of bandwidth.

Journal Article Optics letters · May 2010 Featured Publication 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 ... Full text Cite

Transverse flow imaging based on photoacoustic Doppler bandwidth broadening.

Journal Article Journal of biomedical optics · March 2010 Featured Publication 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 ... Full text Cite

Photoacoustic microscopy using Evans Blue dye as a contrast agent

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · February 23, 2010 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 (RBC) as an endogenous co ... Full text Cite

Invasive and transcranial photoacoustic imaging of the vascular response to brain electrical stimulation

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · February 12, 2010 Advances in the brain functional imaging greatly facilitated the understanding of neurovascular coupling. For monitoring of the microvascular response to the brain electrical stimulation in vivo we used optical-resolution photoacoustic microscopy (OR-PAM) ... Full text Cite

Evans blue dye-enhanced capillary-resolution photoacoustic microscopy in vivo.

Journal Article Journal of biomedical optics · September 2009 Featured Publication 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 co ... Full text Cite

Three-dimensional reconstruction for fluorescence tomography using cylinder phantoms

Journal Article Ruan Jian Xue Bao/Journal of Software · May 1, 2009 Featured Publication Based on the finite element analysis, this study applies three iterative regularization algorithms to the 3D reconstruction of fluorescent yield, including conjugate gradient least square (CGLS), least square QR decomposition (LSQR), and 2-order pre-iterat ... Full text Cite

Modeling and validation of light propagation in free-space for non-contact near-infrared fluorescent tomography

Journal Article Hongwai Yu Haomibo Xuebao/Journal of Infrared and Millimeter Waves · October 1, 2008 Featured Publication Light propagation from the object boundary to detector was presented for non-contact near infrared fluorescent molecular tomography (FMT). Based on the work of Jorge Ripoll et al, perspective projection effect of lens was considered. The formula for light ... Cite

Fluorescent optical imaging of small animals using filtered back-projection 3D surface reconstruction method

Conference BioMedical Engineering and Informatics: New Development and the Future - Proceedings of the 1st International Conference on BioMedical Engineering and Informatics, BMEI 2008 · September 18, 2008 The CCD-based non-contact fluorescent optical imaging has got a promising progress in recent years. This imaging modality needs the 3D surface of the small animal, which is used for the forward model and inverse reconstruction. We propose a new 3D surface ... Full text Cite

A 3D-surface torso reconstruction method used in fluorescence molecular tomography of small animals

Journal Article Chinese Journal of Biomedical Engineering · June 1, 2008 Featured Publication Objective: The CCD-based non-contact fluorescencemolecular tomography has got a rapid progress in recent years. This imaging modality needs to acquire 3D-surface of the animal imaged, which is used as the forward model in the fluorescence concentration rec ... Cite

Full-angle optical imaging of near-infrared fluorescent probes implanted in small animals

Journal Article Progress in Natural Science · January 1, 2008 Featured Publication To provide a valuable experimental platform for in vivo biomedical research of small animal model with fluorescence mediated approach, we developed a whole-body near-infrared fluorescence molecular imaging system as described in this paper. This system is ... Full text Cite