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Abdul-Rahman A, Morgan W, Vukmirovic A, Mehnert A, Obreschow D, Yu DY. Empirical retinal venous pulse wave velocity using modified photoplethysmography. BMC Res Notes 2023; 16:48. [PMID: 37031176 PMCID: PMC10082983 DOI: 10.1186/s13104-023-06309-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 03/14/2023] [Indexed: 04/10/2023] Open
Abstract
OBJECTIVE Using the novel imaging method of high-speed modified photoplethysmography we measured the retinal venous pulse wave velocity in a single case. RESULTS A healthy 30-year-old subject underwent high-speed modified photoplethysmography (120 frames per second) with simultaneous ophthalmodynamometry at 26 Meditron units. A video of the optic nerve was analyzed using custom software. A harmonic regression model was fitted to each pixel in the time series and used to quantify the retinal vascular pulse wave parameters. Retinal venous pulsation at the optic disc was observed as a complex dynamic wall motion, whereas contraction commenced at a point in the vein at the center of the optic disc, and progressed centrifugally. The empirically estimated retinal venous pulse wave velocity at this segment was approximately 22.24694 mm/s. This measurement provides an estimate for future studies in the field.
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Affiliation(s)
- Anmar Abdul-Rahman
- Department of Ophthalmology, Counties Manukau DHB, Auckland, New Zealand.
| | - William Morgan
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Australia
- Lions Eye Institute, University of Western Australia, Perth, Australia
| | - Aleksandar Vukmirovic
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Australia
- Lions Eye Institute, University of Western Australia, Perth, Australia
| | - Andrew Mehnert
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Australia
- Lions Eye Institute, University of Western Australia, Perth, Australia
| | - Danail Obreschow
- International Centre for Radio Astronomy Research (ICRAR), University of Western Australia, Perth, Australia
- International Space Centre, University of Western Australia, Perth, Australia
| | - Dao-Yi Yu
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Australia
- Lions Eye Institute, University of Western Australia, Perth, Australia
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2
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Carson J, Warrander L, Johnstone E, van Loon R. Personalising cardiovascular network models in pregnancy: A two-tiered parameter estimation approach. Int J Numer Method Biomed Eng 2021; 37:e3267. [PMID: 31799783 PMCID: PMC9286682 DOI: 10.1002/cnm.3267] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 08/07/2019] [Accepted: 09/07/2019] [Indexed: 05/26/2023]
Abstract
Uterine artery Doppler waveforms are often studied to determine whether a patient is at risk of developing pathologies such as pre-eclampsia. Many uterine waveform indices have been developed, which attempt to relate characteristics of the waveform with the physiological adaptation of the maternal cardiovascular system, and are often suggested to be an indicator of increased placenta resistance and arterial stiffness. Doppler waveforms of four patients, two of whom developed pre-eclampsia, are compared with a comprehensive closed-loop model of pregnancy. The closed-loop model has been previously validated but has been extended to include an improved parameter estimation technique that utilises systolic and diastolic blood pressure, cardiac output, heart rate, and pulse wave velocity measurements to adapt model resistances, compliances, blood volume, and the mean vessel areas in the main systemic arteries. The shape of the model-predicted uterine artery velocity waveforms showed good agreement with the characteristics observed in the patient Doppler waveforms. The personalised models obtained now allow a prediction of the uterine pressure waveforms in addition to the uterine velocity. This allows for a more detailed mechanistic analysis of the waveforms, eg, wave intensity analysis, to study existing clinical indices. The findings indicate that to accurately estimate arterial stiffness, both pulse pressure and pulse wave velocities are required. In addition, the results predict that patients who developed pre-eclampsia later in pregnancy have larger vessel areas in the main systemic arteries compared with the two patients who had normal pregnancy outcomes.
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Affiliation(s)
- Jason Carson
- Zienkiewicz Centre for Computational Engineering, College of EngineeringSwansea UniversitySwanseaUK
- Data Science Building, Swansea University Medical SchoolSwansea UniversitySwanseaUK
- HDR UK Wales and Northern IrelandHealth Data Research UKLondonUK
| | - Lynne Warrander
- Maternal and Fetal Health Research Centre, Division of Developmental Biology, Faculty of Medicine Biology and HealthUniversity of ManchesterManchesterUK
| | - Edward Johnstone
- Maternal and Fetal Health Research Centre, Division of Developmental Biology, Faculty of Medicine Biology and HealthUniversity of ManchesterManchesterUK
| | - Raoul van Loon
- Zienkiewicz Centre for Computational Engineering, College of EngineeringSwansea UniversitySwanseaUK
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3
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Li Y, Li L, Zhu L, Maslov K, Shi J, Hu P, Bo E, Yao J, Liang J, Wang L, Wang LV. Snapshot Photoacoustic Topography Through an Ergodic Relay for High-throughput Imaging of Optical Absorption. Nat Photonics 2020; 14:164-170. [PMID: 34178097 PMCID: PMC8223468 DOI: 10.1038/s41566-019-0576-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Current embodiments of photoacoustic imaging require either serial detection with a single-element ultrasonic transducer or parallel detection with an ultrasonic array, necessitating a trade-off between cost and throughput. Here, we present photoacoustic topography through an ergodic relay (PATER) for low-cost high-throughput snapshot widefield imaging. Encoding spatial information with randomized temporal signatures through ergodicity, PATER requires only a single-element ultrasonic transducer to capture a widefield image with a single laser shot. We applied PATER to demonstrate both functional imaging of hemodynamic responses and high-speed imaging of blood pulse wave propagation in mice in vivo. Leveraging the high frame rate of 2 kHz, PATER tracked and localized moving melanoma tumor cells in the mouse brain in vivo, which enabled flow velocity quantification and super-resolution imaging. Among the potential biomedical applications of PATER, wearable monitoring of human vital signs in particular is envisaged.
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Affiliation(s)
- Yang Li
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, Campus Box 1097, One Brookings Drive, St. Louis, MO 63130-4899, USA
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Lei Li
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
- Caltech Optical Imaging Laboratory, Department of Electrical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Liren Zhu
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, Campus Box 1097, One Brookings Drive, St. Louis, MO 63130-4899, USA
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Konstantin Maslov
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Junhui Shi
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Peng Hu
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, Campus Box 1097, One Brookings Drive, St. Louis, MO 63130-4899, USA
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - En Bo
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Junjie Yao
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, Campus Box 1097, One Brookings Drive, St. Louis, MO 63130-4899, USA
| | - Jinyang Liang
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, Campus Box 1097, One Brookings Drive, St. Louis, MO 63130-4899, USA
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Lidai Wang
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, Campus Box 1097, One Brookings Drive, St. Louis, MO 63130-4899, USA
| | - Lihong V. Wang
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
- Caltech Optical Imaging Laboratory, Department of Electrical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
- Correspondence should be addressed to L.V.W. ()
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4
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Wei D, Zeng X, Yang Z, Zhou Q, Weng X, He H, Gao W, Gu Z, Wei X. Visualizing Interactions of Circulating Tumor Cell and Dendritic Cell in the Blood Circulation Using In Vivo Imaging Flow Cytometry. IEEE Trans Biomed Eng 2019; 66:2521-2526. [DOI: 10.1109/tbme.2019.2891068] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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5
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Nabeel PM, Kiran VR, Joseph J, Abhidev VV, Sivaprakasam M. Local Pulse Wave Velocity: Theory, Methods, Advancements, and Clinical Applications. IEEE Rev Biomed Eng 2019; 13:74-112. [PMID: 31369386 DOI: 10.1109/rbme.2019.2931587] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Local pulse wave velocity (PWV) is evolving as one of the important determinants of arterial hemodynamics, localized vessel stiffening associated with several pathologies, and a host of other cardiovascular events. Although PWV was introduced over a century ago, only in recent decades, due to various technological advancements, has emphasis been directed toward its measurement from a single arterial section or from piecewise segments of a target arterial section. This emerging worldwide trend in the exploration of instrumental solutions for local PWV measurement has produced several invasive and noninvasive methods. As of yet, however, a univocal opinion on the ideal measurement method has not emerged. Neither have there been extensive comparative studies on the accuracy of the available methods. Recognizing this reality, makes apparent the need to establish guideline-recommended standards for the measurement methods and reference values, without which clinical application cannot be pursued. This paper enumerates all major local PWV measurement methods while pinpointing their salient methodological considerations and emphasizing the necessity of global standardization. Further, a summary of the advancements in measuring modalities and clinical applications is provided. Additionally, a detailed discussion on the minimally explored concept of incremental local PWV is presented along with suggestions of future research questions.
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Karlas A, Fasoula NA, Paul-Yuan K, Reber J, Kallmayer M, Bozhko D, Seeger M, Eckstein HH, Wildgruber M, Ntziachristos V. Cardiovascular optoacoustics: From mice to men - A review. Photoacoustics 2019; 14:19-30. [PMID: 31024796 PMCID: PMC6476795 DOI: 10.1016/j.pacs.2019.03.001] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 03/18/2019] [Indexed: 05/04/2023]
Abstract
Imaging has become an indispensable tool in the research and clinical management of cardiovascular disease (CVD). An array of imaging technologies is considered for CVD diagnostics and therapeutic assessment, ranging from ultrasonography, X-ray computed tomography and magnetic resonance imaging to nuclear and optical imaging methods. Each method has different operational characteristics and assesses different aspects of CVD pathophysiology; nevertheless, more information is desirable for achieving a comprehensive view of the disease. Optoacoustic (photoacoustic) imaging is an emerging modality promising to offer novel information on CVD parameters by allowing high-resolution imaging of optical contrast several centimeters deep inside tissue. Implemented with illumination at several wavelengths, multi-spectral optoacoustic tomography (MSOT) in particular, is sensitive to oxygenated and deoxygenated hemoglobin, water and lipids allowing imaging of the vasculature, tissue oxygen saturation and metabolic or inflammatory parameters. Progress with fast-tuning lasers, parallel detection and advanced image reconstruction and data-processing algorithms have recently transformed optoacoustics from a laboratory tool to a promising modality for small animal and clinical imaging. We review progress with optoacoustic CVD imaging, highlight the research and diagnostic potential and current applications and discuss the advantages, limitations and possibilities for integration into clinical routine.
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Affiliation(s)
- Angelos Karlas
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Clinic for Vascular and Endovascular Surgery, University Hospital rechts der Isar, Munich, Germany
- German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
| | - Nikolina-Alexia Fasoula
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Korbinian Paul-Yuan
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Josefine Reber
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Michael Kallmayer
- Clinic for Vascular and Endovascular Surgery, University Hospital rechts der Isar, Munich, Germany
- German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
| | - Dmitry Bozhko
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Markus Seeger
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Hans-Henning Eckstein
- Clinic for Vascular and Endovascular Surgery, University Hospital rechts der Isar, Munich, Germany
- German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
| | - Moritz Wildgruber
- Institute for Diagnostic and Interventional Radiology, University Hospital rechts der Isar, Munich, Germany
- Institute for Clinical Radiology, University Hospital Muenster, Muenster, Germany
| | - Vasilis Ntziachristos
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
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Semyachkina-Glushkovskaya O, Postnov D, Kurths J. Blood⁻Brain Barrier, Lymphatic Clearance, and Recovery: Ariadne's Thread in Labyrinths of Hypotheses. Int J Mol Sci 2018; 19:ijms19123818. [PMID: 30513598 PMCID: PMC6320935 DOI: 10.3390/ijms19123818] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/21/2018] [Accepted: 11/23/2018] [Indexed: 12/25/2022] Open
Abstract
The peripheral lymphatic system plays a crucial role in the recovery mechanisms after many pathological changes, such as infection, trauma, vascular, or metabolic diseases. The lymphatic clearance of different tissues from waste products, viruses, bacteria, and toxic proteins significantly contributes to the correspondent recovery processes. However, understanding of the cerebral lymphatic functions is a challenging problem. The exploration of mechanisms of lymphatic communication with brain fluids as well as the role of the lymphatic system in brain drainage, clearance, and recovery is still in its infancy. Here we review novel concepts on the anatomy and physiology of the lymphatics in the brain, which warrant a substantial revision of our knowledge about the role of lymphatics in the rehabilitation of the brain functions after neural pathologies. We discuss a new vision on the connective bridge between the opening of a blood–brain barrier and activation of the meningeal lymphatic clearance. The ability to stimulate the lymph flow in the brain, is likely to play an important role in developing future innovative strategies in neurorehabilitation therapy.
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Affiliation(s)
| | - Dmitry Postnov
- Department of Optics and Biophotonics, Saratov State University, 83 Astrakhanskaya str., 410012 Saratov, Russia.
| | - Jürgen Kurths
- Department of Human and Animal Physiology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia.
- Physics Department, Humboldt University, Newtonstrasse 15, 12489 Berlin, Germany.
- Potsdam Institute for Climate Impact Research, Telegrafenberg A31, 14473 Potsdam, Germany.
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8
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Wei D, Pang K, Song Q, Suo Y, He H, Weng X, Gao X, Wei X. Noninvasive monitoring of nanoparticle clearance and aggregation in blood circulation by in vivo flow cytometry. J Control Release 2018; 278:66-73. [PMID: 29625160 DOI: 10.1016/j.jconrel.2018.03.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 03/21/2018] [Accepted: 03/23/2018] [Indexed: 12/22/2022]
Abstract
Nanoparticles have been widely used in biomedical research as drug carriers or imaging agents for living animals. Blood circulation is crucial for the delivery of nanoparticles, which enter the bloodstream through injection, inhalation, or dermal exposure. However, the clearance kinetics of nanoparticles in blood circulation has been poorly studied, mainly because of the limitations of conventional detection methods, such as insufficient blood sample volumes or low spatial-temporal resolution. In addition, formation of nanoparticle aggregates is a key determinant for biocompatibility and drug delivery efficiency. Aggregation behavior of nanoparticles in blood is studied using dynamic light scattering in serum or serum protein solutions, which is still very different from in vivo condition. In this work, we monitored the dynamics of nanoparticle concentration and formation of nanoparticle aggregates in the bloodstream in live animals using in vivo flow cytometry (IVFC). The results indicated that nanoparticles in smaller size could stay longer in the bloodstream. Polyethylene glycol (PEG)-modification could prolong circulating time and reduce the formation of aggregates in the blood circulation. Our work shows that IVFC can be a powerful tool for pharmacokinetic studies of nanoparticles and other drug carriers, assessing cell-targeting efficiency, as well as potentially measuring cardiac output and hepatic function in vivo.
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Affiliation(s)
- Dan Wei
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Med-X Research Institute and School of Biomedical Engineering, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Kai Pang
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Med-X Research Institute and School of Biomedical Engineering, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Qingxiang Song
- Department of Pharmacology and Chemical Biology, Faculty of Basic Medicine, School of Medicine, Shanghai Jiao Tong University, 280 South Chongqing Road, Shanghai 200025, China
| | - Yuanzhen Suo
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Med-X Research Institute and School of Biomedical Engineering, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Department of Chemistry and Chemical Biology, Harvard University, Cambridge 02138, USA
| | - Hao He
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Med-X Research Institute and School of Biomedical Engineering, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Xiaofu Weng
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Med-X Research Institute and School of Biomedical Engineering, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Xiaoling Gao
- Department of Pharmacology and Chemical Biology, Faculty of Basic Medicine, School of Medicine, Shanghai Jiao Tong University, 280 South Chongqing Road, Shanghai 200025, China.
| | - Xunbin Wei
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Med-X Research Institute and School of Biomedical Engineering, Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, 3688 Nanhai Road, Shenzhen 518060, China.
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9
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Li Q, Li L, Chai X, Zhou C. Response to Comment on "Retinal pulse wave velocity measurement using spectral-domain optical coherence tomography". J Biophotonics 2018; 11:e201700379. [PMID: 29251430 DOI: 10.1002/jbio.201700379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 12/14/2017] [Indexed: 06/07/2023]
Abstract
Spahr et al. recently commented on our latest paper "Retinal pulse wave velocity measurement using spectral-domain optical coherence tomography" with a conclusion that the measured retinal pulse wave velocity (rPWV) in our paper was contradictory to theoretical predictions and previously published results. However, the theoretical predictions by Spahr et al. based on Moens-Korteweg equation are questionable, since the Moens-Korteweg equation should not be used for small arteries like retinal arteries. Previously, various measurements of rPWV using different technologies have been reported. The results on human and rats are not consistent. As the rPWV is an unknown value, we argue that the time delay derived between 2 arterial sites should be verified to see if the delay truly represents the pulse wave transit time. In the future, special emphasis should be placed on demonstration of the reproducibility of technologies and data analysis of large samples.
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Affiliation(s)
- Qian Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Lin Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Xinyu Chai
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Chuanqing Zhou
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
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Spahr H, Hillmann D, Pfäffle C, Hüttmann G. Comment on "Retinal pulse wave velocity measurement using spectral-domain optical coherence tomography". J Biophotonics 2018; 11:e201700347. [PMID: 29219240 DOI: 10.1002/jbio.201700347] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 11/23/2017] [Indexed: 06/07/2023]
Abstract
This paper comments on the article "Retinal pulse wave velocity measurement using spectral-domain optical coherence tomography" by Qian Li et al. The authors propose a method to determine the pulse wave velocity in retinal arteries and veins. This method should enable a noninvasive determination of biomechanical properties of the vessel network, particularly the elasticity of the vessel walls. Although the observations the authors made might seem reasonable at first glance, they are in fact highly surprising and contradictory to theoretical predictions and previously published results.
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Affiliation(s)
- Hendrik Spahr
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
- Medical Laser Center Lübeck GmbH, Lübeck, Germany
| | | | - Clara Pfäffle
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
- Medical Laser Center Lübeck GmbH, Lübeck, Germany
| | - Gereon Hüttmann
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
- Medical Laser Center Lübeck GmbH, Lübeck, Germany
- Airway Research Center North (ARCN), Member of the German Center for Lung Research (DZL), Germany
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Abstract
Photoacoustic tomography (PAT) has become one of the fastest growing fields in biomedical optics. Unlike pure optical imaging, such as confocal microscopy and two-photon microscopy, PAT employs acoustic detection to image optical absorption contrast with high-resolution deep into scattering tissue. So far, PAT has been widely used for multiscale anatomical, functional, and molecular imaging of biological tissues. We focus on PAT’s basic principles, major implementations, imaging contrasts, and recent applications.
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Affiliation(s)
- Yong Zhou
- Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, One Brookings Drive, Campus Box 1097, St. Louis, Missouri 63130, United States
| | - Junjie Yao
- Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, One Brookings Drive, Campus Box 1097, St. Louis, Missouri 63130, United States
| | - Lihong V. Wang
- Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, One Brookings Drive, Campus Box 1097, St. Louis, Missouri 63130, United States
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12
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Yeh C, Liang J, Zhou Y, Hu S, Sohn RE, Arbeit JM, Wang LV. Photoacoustic microscopy of arteriovenous shunts and blood diffusion in early-stage tumors. J Biomed Opt 2016; 21:20501. [PMID: 26882446 PMCID: PMC4814546 DOI: 10.1117/1.jbo.21.2.020501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 01/21/2016] [Indexed: 05/03/2023]
Abstract
Angiogenesis in a tumor region creates arteriovenous (AV) shunts that cause an abnormal venous blood oxygen saturation ( sO2 ) distribution. Here, we applied optical-resolution photoacoustic microscopy to study the AV shunting in vivo. First, we built a phantom to image sO2 distribution in a vessel containing converged flows from two upstream blood vessels with different sO2 values. The phantom experiment showed that the blood from the two upstream vessels maintained a clear sO2 boundary for hundreds of seconds, which is consistent with our theoretical analysis using a diffusion model. Next, we xenotransplanted O-786 tumor cells in mouse ears and observed abnormal sO2 distribution in the downstream vein from the AV shunts in vivo. Finally, we identified the tumor location by tracing the sO2 distribution. Our study suggests that abnormal sO2 distribution induced by the AV shunts in the vessel network may be used as a new functional benchmark for early tumor detection.
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Affiliation(s)
- Chenghung Yeh
- Washington University in St. Louis, Department of Electrical and Systems Engineering, One Brookings Drive, St. Louis, Missouri 63130, United States
| | - Jinyang Liang
- Washington University in St. Louis, Department of Biomedical Engineering, One Brookings Drive, St. Louis, Missouri 63130, United States
| | - Yong Zhou
- Washington University in St. Louis, Department of Biomedical Engineering, One Brookings Drive, St. Louis, Missouri 63130, United States
| | - Song Hu
- University of Virginia, Department of Biomedical Engineering, PO Box 800759, Charlottesville, Virginia 22908, United States
| | - Rebecca E. Sohn
- Washington University School of Medicine, Department of Surgery, Urology Division, St. Louis, Missouri 63130, United States
| | - Jeffrey M. Arbeit
- Washington University School of Medicine, Department of Surgery, Urology Division, St. Louis, Missouri 63130, United States
- Address all correspondence to: Jeffrey M. Arbeit, E-mail: ; Lihong V. Wang, E-mail:
| | - Lihong V. Wang
- Washington University in St. Louis, Department of Electrical and Systems Engineering, One Brookings Drive, St. Louis, Missouri 63130, United States
- Washington University in St. Louis, Department of Biomedical Engineering, One Brookings Drive, St. Louis, Missouri 63130, United States
- Address all correspondence to: Jeffrey M. Arbeit, E-mail: ; Lihong V. Wang, E-mail:
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Abstract
Photoacoustic tomography (PAT) combines rich optical absorption contrast with the high spatial resolution of ultrasound at depths in tissue. The high scalability of PAT has enabled anatomical imaging of biological structures ranging from organelles to organs. The inherent functional and molecular imaging capabilities of PAT have further allowed it to measure important physiological parameters and track critical cellular activities. Integration of PAT with other imaging technologies provides complementary capabilities and can potentially accelerate the clinical translation of PAT.
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Affiliation(s)
- Junjie Yao
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, MO, USA
| | - Jun Xia
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, MO, USA Department of Biomedical Engineering, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Lihong V Wang
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, MO, USA
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Ning B, Sun N, Cao R, Chen R, Kirk Shung K, Hossack JA, Lee JM, Zhou Q, Hu S. Ultrasound-aided Multi-parametric Photoacoustic Microscopy of the Mouse Brain. Sci Rep 2015; 5:18775. [PMID: 26688368 DOI: 10.1038/srep18775] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 11/16/2015] [Indexed: 12/24/2022] Open
Abstract
High-resolution quantitative imaging of cerebral oxygen metabolism in mice is crucial for understanding brain functions and formulating new strategies to treat neurological disorders, but remains a challenge. Here, we report on our newly developed ultrasound-aided multi-parametric photoacoustic microscopy (PAM), which enables simultaneous quantification of the total concentration of hemoglobin (CHb), the oxygen saturation of hemoglobin (sO2), and cerebral blood flow (CBF) at the microscopic level and through the intact mouse skull. The three-dimensional skull and vascular anatomies delineated by the dual-contrast (i.e., ultrasonic and photoacoustic) system provide important guidance for dynamically focused contour scan and vessel orientation-dependent correction of CBF, respectively. Moreover, bi-directional raster scan allows determining the direction of blood flow in individual vessels. Capable of imaging all three hemodynamic parameters at the same spatiotemporal scale, our ultrasound-aided PAM fills a critical gap in preclinical neuroimaging and lays the foundation for high-resolution mapping of the cerebral metabolic rate of oxygen (CMRO2)-a quantitative index of cerebral oxygen metabolism. This technical innovation is expected to shed new light on the mechanism and treatment of a broad spectrum of neurological disorders, including Alzheimer's disease and ischemic stroke.
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Spahr H, Hillmann D, Hain C, Pfäffle C, Sudkamp H, Franke G, Hüttmann G. Imaging pulse wave propagation in human retinal vessels using full-field swept-source optical coherence tomography. Opt Lett 2015; 40:4771-4. [PMID: 26469616 DOI: 10.1364/ol.40.004771] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We demonstrate a new noninvasive method to assess biomechanical properties of the retinal vascular system. Phase-sensitive full-field swept-source optical coherence tomography (PhS-FF-SS-OCT) is used to investigate retinal vascular dynamics at unprecedented temporal resolution. The motion of retinal tissue that is induced by expansion of the vessels therein is measured with an accuracy of about 10 nm. The pulse shapes of arterial and venous pulsations, their temporal delays, as well as the frequency-dependent pulse propagation through the capillary bed, are determined. For the first time, imaging speed and motion sensitivity are sufficient for a direct measurement of pulse waves propagating with more than 600 mm/s in retinal vessels of a healthy young subject.
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Zhou Y, Poudel J, Li G, Wang LV. In vivo photoacoustic flowmetry at depths of the diffusive regime based on saline injection. J Biomed Opt 2015; 20:87001. [PMID: 26267364 PMCID: PMC4681378 DOI: 10.1117/1.jbo.20.8.087001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 07/20/2015] [Indexed: 05/23/2023]
Abstract
We propose a saline injection-based method to quantify blood flow velocity in vivo with acoustic-resolution photoacoustic tomography. By monitoring the saline–blood interface propagating in the blood vessel, the flow velocity can be resolved. We first demonstrated our method in phantom experiments, where a root mean square error of prediction of 0.29 mm/s was achieved. By injecting saline into a mouse tail vein covered with 1 mm chicken tissue, we showed that the flow velocity in the tail vein could be measured at depths, which is especially pertinent to monitoring blood flow velocity in patients undergoing intravenous infusion.
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Affiliation(s)
- Yong Zhou
- Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, 1 Brookings Drive, Campus Box 1097, St. Louis, Missouri 63130, United States
| | - Joemini Poudel
- Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, 1 Brookings Drive, Campus Box 1097, St. Louis, Missouri 63130, United States
| | - Guo Li
- Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, 1 Brookings Drive, Campus Box 1097, St. Louis, Missouri 63130, United States
| | - Lihong V. Wang
- Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, 1 Brookings Drive, Campus Box 1097, St. Louis, Missouri 63130, United States
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Lee JA, Kozikowski RT, Sorg BS. In vivo microscopy of microvessel oxygenation and network connections. Microvasc Res 2014; 98:29-39. [PMID: 25500481 DOI: 10.1016/j.mvr.2014.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 11/20/2014] [Accepted: 11/25/2014] [Indexed: 12/20/2022]
Abstract
Abnormal or compromised microvascular function is a key component of various diseases. In vivo microscopy of microvessel function in preclinical models can be useful for the study of a disease state and effects of new treatments. Wide-field imaging of microvascular oxygenation via hemoglobin (Hb) saturation measurements has been applied in various applications alone and in combination with other measures of microvessel function, such as blood flow. However, most current combined imaging methods of microvessel function do not provide direct information on microvessel network connectivity or changes in connections and blood flow pathways. First-pass fluorescence (FPF) imaging of a systemically administered fluorescent contrast agent can be used to directly image blood flow pathways and connections relative to a local supplying arteriole in a quantitative manner through measurement of blood supply time (BST). Here, we demonstrate the utility of information produced by the combination of Hb saturation measurements via spectral imaging with BST measurements via FPF imaging for correlation of microvessel oxygenation with blood flow pathways and connections throughout a local network. Specifically, we show network pathway effects on oxygen transport in normal microvessels, dynamic changes associated with wound healing, and pathological effects of abnormal angiogenesis in tumor growth and development.
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Affiliation(s)
- Jennifer A Lee
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32610, USA.
| | | | - Brian S Sorg
- National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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18
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Yeh C, Soetikno B, Hu S, Maslov KI, Wang LV. Microvascular quantification based on contour-scanning photoacoustic microscopy. J Biomed Opt 2014; 19:96011. [PMID: 25223708 PMCID: PMC4164706 DOI: 10.1117/1.jbo.19.9.096011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 08/27/2014] [Indexed: 05/04/2023]
Abstract
Accurate quantification of microvasculature remains of interest in fundamental pathophysiological studies and clinical trials. Current photoacoustic microscopy can noninvasively quantify properties of the microvasculature, including vessel density and diameter, with a high spatial resolution. However, the depth range of focus (i.e., focal zone) of optical-resolution photoacoustic microscopy (OR-PAM) is often insufficient to encompass the depth variations of features of interest—such as blood vessels—due to uneven tissue surfaces. Thus, time-consuming image acquisitions at multiple different focal planes are required to maintain the region of interest in the focal zone. We have developed continuous three-dimensional motorized contour-scanning OR-PAM, which enables real-time adjustment of the focal plane to track the vessels’ profile. We have experimentally demonstrated that contour scanning improves the signal-to-noise ratio of conventional OR-PAM by as much as 41% and shortens the image acquisition time by 3.2 times. Moreover, contour-scanning OR-PAM more accurately quantifies vessel density and diameter, and has been applied to studying tumors with uneven surfaces.
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Affiliation(s)
- Chenghung Yeh
- Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, One Brookings Drive, St. Louis, Missouri 63130, United States
| | - Brian Soetikno
- Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, One Brookings Drive, St. Louis, Missouri 63130, United States
| | - Song Hu
- Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, One Brookings Drive, St. Louis, Missouri 63130, United States
- University of Virginia, Department of Biomedical Engineering, PO Box 800759, Charlottesville, Virginia 22908, United States
| | - Konstantin I. Maslov
- Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, One Brookings Drive, St. Louis, Missouri 63130, United States
| | - Lihong V. Wang
- Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, One Brookings Drive, St. Louis, Missouri 63130, United States
- Address all correspondence to: Lihong V. Wang, E-mail:
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Winkler AM, Maslov K, Wang LV. Noise-equivalent sensitivity of photoacoustics. J Biomed Opt 2013; 18:097003. [PMID: 24026425 PMCID: PMC3769636 DOI: 10.1117/1.jbo.18.9.097003] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 08/04/2013] [Accepted: 08/07/2013] [Indexed: 05/18/2023]
Abstract
The fundamental limitations of photoacoustic microscopy for detecting optically absorbing molecules are investigated both theoretically and experimentally. We experimentally demonstrate noise-equivalent detection sensitivities of 160,000 methylene blue molecules (270 zeptomol or 2.7×10-19 mol) and 86,000 oxygenated hemoglobin molecules (140 zeptomol) using narrowband continuous-wave photoacoustics. The ultimate sensitivity of photoacoustics is fundamentally limited by thermal noise, which can present in the acoustic detection system as well as in the medium itself. Under the optimized conditions described herein and using commercially available detectors, photoacoustic microscopy can detect as few as 100s of oxygenated hemoglobin molecules. Realizable improvements to the detector may enable single molecule detection of select molecules.
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Affiliation(s)
- Amy M. Winkler
- Washington University in St. Louis, Department of Biomedical Engineering, One Brookings Drive, St. Louis, Missouri 63130
| | - Konstantin Maslov
- Washington University in St. Louis, Department of Biomedical Engineering, One Brookings Drive, St. Louis, Missouri 63130
| | - Lihong V. Wang
- Washington University in St. Louis, Department of Biomedical Engineering, One Brookings Drive, St. Louis, Missouri 63130
- Address all correspondence to: Lihong V. Wang, Washington University in St. Louis, Department of Biomedical Engineering, One Brookings Drive, St. Louis, Missouri 63130. Tel: +314-935-6152; Fax: +314-935-7448; E-mail:
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20
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Abstract
Photoacoustic microscopy (PAM) is a hybrid in vivo imaging technique that acoustically detects optical contrast via the photoacoustic effect. Unlike pure optical microscopic techniques, PAM takes advantage of the weak acoustic scattering in tissue and thus breaks through the optical diffusion limit (~1 mm in soft tissue). With its excellent scalability, PAM can provide high-resolution images at desired maximum imaging depths up to a few millimeters. Compared with backscattering-based confocal microscopy and optical coherence tomography, PAM provides absorption contrast instead of scattering contrast. Furthermore, PAM can image more molecules, endogenous or exogenous, at their absorbing wavelengths than fluorescence-based methods, such as wide-field, confocal, and multi-photon microscopy. Most importantly, PAM can simultaneously image anatomical, functional, molecular, flow dynamic and metabolic contrasts in vivo. Focusing on state-of-the-art developments in PAM, this Review discusses the key features of PAM implementations and their applications in biomedical studies.
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Affiliation(s)
- Junjie Yao
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Lihong V. Wang
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
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21
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Hu S, Wang L. Optical-resolution photoacoustic microscopy: auscultation of biological systems at the cellular level. Biophys J 2013; 105:841-7. [PMID: 23972836 PMCID: PMC3752103 DOI: 10.1016/j.bpj.2013.07.017] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 06/16/2013] [Accepted: 07/12/2013] [Indexed: 11/19/2022] Open
Abstract
Photoacoustic microscopy (PAM) offers unprecedented sensitivity to optical absorption and opens a new window to study biological systems at multiple length- and timescales. In particular, optical-resolution PAM (OR-PAM) has pushed the technical envelope to submicron length scales and millisecond timescales. Here, we review the state of the art of OR-PAM in biophysical research. With properly chosen optical wavelengths, OR-PAM can spectrally differentiate a variety of endogenous and exogenous chromophores, unveiling the anatomical, functional, metabolic, and molecular information of biological systems. Newly uncovered contrast mechanisms of linear dichroism and Förster resonance energy transfer further distinguish OR-PAM. Integrating multiple contrasts and advanced scanning mechanisms has capacitated OR-PAM to comprehensively interrogate biological systems at the cellular level in real time. Two future directions are discussed, where OR-PAM holds the potential to translate basic biophysical research into clinical healthcare.
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Affiliation(s)
- Song Hu
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Lihong V. Wang
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri
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