Scholars@Duke
Junjie Yao

Junjie Yao

Jeffrey N. Vinik 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)  

Featured Works

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

Journal article Advanced drug delivery reviews · May 2024 Featured Publication 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

Longitudinal intravital imaging of mouse placenta.

Journal article Sci Adv · March 22, 2024 Featured Publication 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 Open Access Link to item Cite

Multi-molecular hyperspectral PRM-SRS microscopy.

Journal article Nat Commun · February 21, 2024 Featured Publication 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 Featured Publication 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

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

Journal article IEEE Trans Med Imaging · February 2024 Featured Publication 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 Link to item Cite

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

Journal article Journal of biomedical optics · January 2024 Featured Publication 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 Featured Publication 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 Featured Publication 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 Featured Publication 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 Featured Publication 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

From Ultraviolet to Near-Infrared: Label-Free Reflection-Mode Hyperspectral Photoacoustic Microscopy for Single-Cell Biochemical Mapping

Journal article GEN Biotechnology · October 1, 2023 Featured Publication Hyperspectral imaging has emerged as a valuable technique for analyzing biological tissue compositions by probing intrinsic or exogenous biomolecules. However, conventional hyperspectral imaging methods predominantly rely on fl ... Full text Cite

Multiscale photoacoustic tomography using reversibly switchable thermochromics.

Journal article Journal of biomedical optics · August 2023 Featured Publication 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 Featured Publication 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 Featured Publication 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 Featured Publication 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

Editorial: Breaking the speed limits in photoacoustic microscopy.

Journal article Photoacoustics · August 2023 Featured Publication Full text Cite

Non-invasive Deep-Brain Imaging with 3D Integrated Photoacoustic Tomography and Ultrasound Localization Microscopy (3D-PAULM).

Journal article ArXiv · July 27, 2023 Featured Publication Photoacoustic computed tomography (PACT) is a proven technology for imaging hemodynamics in deep brain of small animal models. PACT is inherently compatible with ultrasound (US) imaging, providing complementary contrast mechanisms. While PACT can quantify ... Link to item Cite

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

Journal article J Vis Exp · June 2, 2023 Featured Publication 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 Med Nov Technol Devices · June 2023 Featured Publication 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 Link to item Cite

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

Journal article J Vis Exp · April 14, 2023 Featured Publication 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 Featured Publication 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 Featured Publication 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 Featured Publication 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 Open Access Cite

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

Journal article Nanoscale · March 2023 Featured Publication 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 Featured Publication 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

Time-resolved passive cavitation mapping using the transient angular spectrum approach

Conference The Journal of the Acoustical Society of America · March 1, 2023 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. This study investigates a transient angular spectrum (AS) approach fo ... Full text Cite

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

Journal article Photoacoustics · February 2023 Featured Publication 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 Featured Publication 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

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

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

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

Editorial: Advances in Photoacoustic Neuroimaging.

Journal article Frontiers in neuroscience · January 2022 Featured Publication 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

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

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

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

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

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

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

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

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

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

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

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

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

Journal article Light, science & applications · June 2017 Featured Publication 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

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

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

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

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

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

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

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

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

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

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

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

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

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

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