1
|
Karlas A, Fasoula NA, Katsouli N, Kallmayer M, Sieber S, Schmidt S, Liapis E, Halle M, Eckstein HH, Ntziachristos V. Skeletal muscle optoacoustics reveals patterns of circulatory function and oxygen metabolism during exercise. PHOTOACOUSTICS 2023; 30:100468. [PMID: 36950518 PMCID: PMC10025091 DOI: 10.1016/j.pacs.2023.100468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
Imaging skeletal muscle function and metabolism, as reported by local hemodynamics and oxygen kinetics, can elucidate muscle performance, severity of an underlying disease or outcome of a treatment. Herein, we used multispectral optoacoustic tomography (MSOT) to image hemodynamics and oxygen kinetics within muscle during exercise. Four healthy volunteers underwent three different hand-grip exercise challenges (60s isometric, 120s intermittent isometric and 60s isotonic). During isometric contraction, MSOT showed a decrease of HbO2, Hb and total blood volume (TBV), followed by a prominent increase after the end of contraction. Corresponding hemodynamic behaviors were recorded during the intermittent isometric and isotonic exercises. A more detailed analysis of MSOT readouts revealed insights into arteriovenous oxygen differences and muscle oxygen consumption during all exercise schemes. These results demonstrate an excellent capability of visualizing both circulatory function and oxygen metabolism within skeletal muscle under exercise, with great potential implications for muscle research, including relevant disease diagnostics.
Collapse
Affiliation(s)
- Angelos Karlas
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Chair of Biological Imaging at the Central Institute for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, Munich, Germany
- Department for Vascular and Endovascular Surgery, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| | - Nikolina-Alexia Fasoula
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Chair of Biological Imaging at the Central Institute for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, Munich, Germany
| | - Nikoletta Katsouli
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Chair of Biological Imaging at the Central Institute for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, Munich, Germany
| | - Michael Kallmayer
- Department for Vascular and Endovascular Surgery, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Sabine Sieber
- Department for Vascular and Endovascular Surgery, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Sebastian Schmidt
- Department for Vascular and Endovascular Surgery, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Evangelos Liapis
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Chair of Biological Imaging at the Central Institute for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, Munich, Germany
| | - Martin Halle
- DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
- Department of Prevention and Sports Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Hans-Henning Eckstein
- Department for Vascular and Endovascular Surgery, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| | - Vasilis Ntziachristos
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Chair of Biological Imaging at the Central Institute for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, Munich, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| |
Collapse
|
2
|
Karlas A, Pleitez MA, Aguirre J, Ntziachristos V. Optoacoustic imaging in endocrinology and metabolism. Nat Rev Endocrinol 2021; 17:323-335. [PMID: 33875856 DOI: 10.1038/s41574-021-00482-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/19/2021] [Indexed: 02/02/2023]
Abstract
Imaging is an essential tool in research, diagnostics and the management of endocrine disorders. Ultrasonography, nuclear medicine techniques, MRI, CT and optical methods are already used for applications in endocrinology. Optoacoustic imaging, also termed photoacoustic imaging, is emerging as a method for visualizing endocrine physiology and disease at different scales of detail: microscopic, mesoscopic and macroscopic. Optoacoustic contrast arises from endogenous light absorbers, such as oxygenated and deoxygenated haemoglobin, lipids and water, or exogenous contrast agents, and reveals tissue vasculature, perfusion, oxygenation, metabolic activity and inflammation. The development of high-performance optoacoustic scanners for use in humans has given rise to a variety of clinical investigations, which complement the use of the technology in preclinical research. Here, we review key progress with optoacoustic imaging technology as it relates to applications in endocrinology; for example, to visualize thyroid morphology and function, and the microvasculature in diabetes mellitus or adipose tissue metabolism, with particular focus on multispectral optoacoustic tomography and raster-scan optoacoustic mesoscopy. We explain the merits of optoacoustic microscopy and focus on mid-infrared optoacoustic microscopy, which enables label-free imaging of metabolites in cells and tissues. We showcase current optoacoustic applications within endocrinology and discuss the potential of these technologies to advance research and clinical practice.
Collapse
Affiliation(s)
- Angelos Karlas
- Chair of Biological Imaging, Center for Translational Cancer Research (TranslaTUM), Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Department of Vascular and Endovascular Surgery, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- Munich Partner Site, German Center for Cardiovascular Research (DZHK), Munich, Germany
| | - Miguel A Pleitez
- Chair of Biological Imaging, Center for Translational Cancer Research (TranslaTUM), Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Juan Aguirre
- Chair of Biological Imaging, Center for Translational Cancer Research (TranslaTUM), Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Vasilis Ntziachristos
- Chair of Biological Imaging, Center for Translational Cancer Research (TranslaTUM), Technical University of Munich, Munich, Germany.
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany.
| |
Collapse
|
3
|
Chen Q, Qin W, Qi W, Xi L. Progress of clinical translation of handheld and semi-handheld photoacoustic imaging. PHOTOACOUSTICS 2021; 22:100264. [PMID: 33868921 PMCID: PMC8040335 DOI: 10.1016/j.pacs.2021.100264] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 03/10/2021] [Accepted: 03/10/2021] [Indexed: 05/05/2023]
Abstract
Photoacoustic imaging (PAI), featuring rich contrast, high spatial/temporal resolution and deep penetration, is one of the fastest-growing biomedical imaging technology over the last decade. To date, numbers of handheld and semi-handheld photoacoustic imaging devices have been reported with corresponding potential clinical applications. Here, we summarize emerged handheld and semi-handheld systems in terms of photoacoustic computed tomography (PACT), optoacoustic mesoscopy (OAMes), and photoacoustic microscopy (PAM). We will discuss each modality in three aspects: laser delivery, scanning protocol, and acoustic detection. Besides new technical developments, we also review the associated clinical studies, and the advantages/disadvantages of these new techniques. In the end, we propose the challenges and perspectives of miniaturized PAI in the future.
Collapse
Affiliation(s)
- Qian Chen
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 610054, China
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Wei Qin
- School of Physics, University of Electronics Science and Technology of China, Chengdu, 610054, China
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Weizhi Qi
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Lei Xi
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| |
Collapse
|
4
|
Olefir I, Tzoumas S, Restivo C, Mohajerani P, Xing L, Ntziachristos V. Deep Learning-Based Spectral Unmixing for Optoacoustic Imaging of Tissue Oxygen Saturation. IEEE TRANSACTIONS ON MEDICAL IMAGING 2020; 39:3643-3654. [PMID: 32746111 PMCID: PMC7671861 DOI: 10.1109/tmi.2020.3001750] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Label free imaging of oxygenation distribution in tissues is highly desired in numerous biomedical applications, but is still elusive, in particular in sub-epidermal measurements. Eigenspectra multispectral optoacoustic tomography (eMSOT) and its Bayesian-based implementation have been introduced to offer accurate label-free blood oxygen saturation (sO2) maps in tissues. The method uses the eigenspectra model of light fluence in tissue to account for the spectral changes due to the wavelength dependent attenuation of light with tissue depth. eMSOT relies on the solution of an inverse problem bounded by a number of ad hoc hand-engineered constraints. Despite the quantitative advantage offered by eMSOT, both the non-convex nature of the optimization problem and the possible sub-optimality of the constraints may lead to reduced accuracy. We present herein a neural network architecture that is able to learn how to solve the inverse problem of eMSOT by directly regressing from a set of input spectra to the desired fluence values. The architecture is composed of a combination of recurrent and convolutional layers and uses both spectral and spatial features for inference. We train an ensemble of such networks using solely simulated data and demonstrate how this approach can improve the accuracy of sO2 computation over the original eMSOT, not only in simulations but also in experimental datasets obtained from blood phantoms and small animals (mice) in vivo. The use of a deep-learning approach in optoacoustic sO2 imaging is confirmed herein for the first time on ground truth sO2 values experimentally obtained in vivo and ex vivo.
Collapse
|
5
|
Yang J, Zhang G, Chang W, Chi Z, Shang Q, Wu M, Pan T, Huang L, Jiang H. Photoacoustic imaging of hemodynamic changes in forearm skeletal muscle during cuff occlusion. BIOMEDICAL OPTICS EXPRESS 2020; 11:4560-4570. [PMID: 32923064 PMCID: PMC7449729 DOI: 10.1364/boe.392221] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/30/2020] [Accepted: 07/01/2020] [Indexed: 05/20/2023]
Abstract
Characterizations of circulatory and metabolic function in skeletal muscle are of great importance in clinical settings. Here in this study, we investigate the utility of photoacoustic tomography (PAT) to monitor the hemodynamic changes in forearm skeletal muscle during cuff occlusion. We show high quality photoacoustic (PA) images of human forearm in comparison with ultrasound images. Besides, we track the hemodynamic changes in the forearm during cuff occlusion cross-validated with near-infrared spectroscopy. Our study suggests that PAT, as a new tool, could be applied to common diseases affecting skeletal muscle in the future.
Collapse
Affiliation(s)
- Jinge Yang
- School of Optoelectric Engineering, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Guang Zhang
- School of Electronic Science and Engineering (National Exemplary School of Microelectronics), University of Electronic Science and Technology of China, Chengdu 611731, China
- Center for Information in Medicine, University of Electronic and Technology of China, Chengdu 611731, China
| | - Wu Chang
- School of Electronic Science and Engineering (National Exemplary School of Microelectronics), University of Electronic Science and Technology of China, Chengdu 611731, China
- Center for Information in Medicine, University of Electronic and Technology of China, Chengdu 611731, China
| | - Zihui Chi
- School of Optoelectric Engineering, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Qiquan Shang
- School of Electronic Science and Engineering (National Exemplary School of Microelectronics), University of Electronic Science and Technology of China, Chengdu 611731, China
- Center for Information in Medicine, University of Electronic and Technology of China, Chengdu 611731, China
| | - Man Wu
- School of Electronic Science and Engineering (National Exemplary School of Microelectronics), University of Electronic Science and Technology of China, Chengdu 611731, China
- Center for Information in Medicine, University of Electronic and Technology of China, Chengdu 611731, China
| | - Teng Pan
- School of Electronic Science and Engineering (National Exemplary School of Microelectronics), University of Electronic Science and Technology of China, Chengdu 611731, China
- Center for Information in Medicine, University of Electronic and Technology of China, Chengdu 611731, China
| | - Lin Huang
- School of Electronic Science and Engineering (National Exemplary School of Microelectronics), University of Electronic Science and Technology of China, Chengdu 611731, China
- Center for Information in Medicine, University of Electronic and Technology of China, Chengdu 611731, China
| | - Huabei Jiang
- Department of Medical Engineering, University of South Florida, Tampa 33620, USA
| |
Collapse
|
6
|
Karlas A, Kallmayer M, Fasoula NA, Liapis E, Bariotakis M, Krönke M, Anastasopoulou M, Reber J, Eckstein HH, Ntziachristos V. Multispectral optoacoustic tomography of muscle perfusion and oxygenation under arterial and venous occlusion: A human pilot study. JOURNAL OF BIOPHOTONICS 2020; 13:e201960169. [PMID: 32134550 DOI: 10.1002/jbio.201960169] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/26/2020] [Accepted: 02/11/2020] [Indexed: 05/21/2023]
Abstract
Perfusion and oxygenation are critical parameters of muscle metabolism in health and disease. They have been both the target of many studies, in particular using near-infrared spectroscopy (NIRS). However, difficulties with quantifying NIRS signals have limited a wide dissemination of the method to the clinics. Our aim was to investigate whether clinical multispectral optoacoustic tomography (MSOT) could enable the label-free imaging of muscle perfusion and oxygenation under clinically relevant challenges: the arterial and venous occlusion. We employed a hybrid clinical MSOT/ultrasound system equipped with a hand-held scanning probe to visualize hemodynamic and oxygenation changes in skeletal muscle under arterial and venous occlusions. Four (N = 4) healthy volunteers were scanned over the forearm for both 3-minute occlusion challenges. MSOT-recorded pathophysiologically expected results during tests of disturbed blood flow with high resolution and without the need for contrast agents. During arterial occlusion, MSOT-extracted Hb-values showed an increase, while HbO2 - and total blood volume (TBV)-values remained roughly steady, followed by a discrete increase during the hyperemic period after cuff deflation. During venous occlusion, results showed a clear increase in intramuscular HbO2 , Hb and TBV within the segmented muscle area. MSOT was found to be capable of label-free non-invasive imaging of muscle hemodynamics and oxygenation under arterial and venous occlusion. We introduce herein MSOT as a novel modality for the assessment of vascular disorders characterized by disturbed blood flow, such as acute limb ischemia and venous thrombosis.
Collapse
Affiliation(s)
- Angelos Karlas
- Chair for Biological Imaging, Center for Translational Cancer Research (TranslaTUM), Technical University of Munich, Munich, Germany
- Helmholtz Zentrum München, Institute of Biological and Medical Imaging, Neuherberg, Germany
- Clinic of Vascular and Endovascular Surgery, Technical University of Munich, Munich, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
| | - Michael Kallmayer
- Clinic of Vascular and Endovascular Surgery, Technical University of Munich, Munich, Germany
| | - Nikolina-Alexia Fasoula
- Chair for Biological Imaging, Center for Translational Cancer Research (TranslaTUM), Technical University of Munich, Munich, Germany
- Helmholtz Zentrum München, Institute of Biological and Medical Imaging, Neuherberg, Germany
| | - Evangelos Liapis
- Chair for Biological Imaging, Center for Translational Cancer Research (TranslaTUM), Technical University of Munich, Munich, Germany
- Helmholtz Zentrum München, Institute of Biological and Medical Imaging, Neuherberg, Germany
| | - Michail Bariotakis
- Chair for Biological Imaging, Center for Translational Cancer Research (TranslaTUM), Technical University of Munich, Munich, Germany
- Helmholtz Zentrum München, Institute of Biological and Medical Imaging, Neuherberg, Germany
| | - Markus Krönke
- Clinic of Nuclear Medicine, Technical University of Munich, Klinikum Rechts der Isar, Germany
| | - Maria Anastasopoulou
- Chair for Biological Imaging, Center for Translational Cancer Research (TranslaTUM), Technical University of Munich, Munich, Germany
- Helmholtz Zentrum München, Institute of Biological and Medical Imaging, Neuherberg, Germany
| | - Josefine Reber
- Chair for Biological Imaging, Center for Translational Cancer Research (TranslaTUM), Technical University of Munich, Munich, Germany
- Helmholtz Zentrum München, Institute of Biological and Medical Imaging, Neuherberg, Germany
| | - Hans-Henning Eckstein
- Clinic of Vascular and Endovascular Surgery, Technical University of Munich, Munich, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
| | - Vasilis Ntziachristos
- Chair for Biological Imaging, Center for Translational Cancer Research (TranslaTUM), Technical University of Munich, Munich, Germany
- Helmholtz Zentrum München, Institute of Biological and Medical Imaging, Neuherberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
| |
Collapse
|
7
|
Sowers T, Yoon H, Emelianov S. Investigation of light delivery geometries for photoacoustic applications using Monte Carlo simulations with multiple wavelengths, tissue types, and species characteristics. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-16. [PMID: 31975577 PMCID: PMC6976898 DOI: 10.1117/1.jbo.25.1.016005] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 12/18/2019] [Indexed: 05/24/2023]
Abstract
Combined ultrasound and photoacoustic imaging systems are being developed for biomedical and clinical applications. One common probe configuration is to use a linear transducer array with external light delivery to produce coregistered ultrasound and photoacoustic images. The diagnostic capability of these systems is dependent on the effectiveness of light delivery to the imaging target. We use Monte Carlo modeling to investigate the optimal design geometry of an integrated probe. Simulations are conducted with multiple tissue compositions and wavelengths. The effect of a skin layer with the thickness of a mouse or a human is also considered. The model was validated using a tissue-mimicking gelatin phantom and corresponding Monte Carlo simulations. The optimal illumination angle is shallower with human skin thickness, whereas intermediate angles are ideal with mouse skin thickness. The effect of skin thickness explains differences in the results of prior work. The simulations also indicate that even with identical hardware and imaging parameters, light delivery will be up to 3 × smaller in humans than in mice, due to the increased scattering from thicker skin. Our findings have clear implications for the many researchers using mice to test and develop imaging methods for clinical translation.
Collapse
Affiliation(s)
- Timothy Sowers
- Georgia Institute of Technology, Parker H. Petit Institute for Bioengineering and Bioscience, Atlanta, Georgia, United States
- Georgia Institute of Technology, George W. Woodruff School of Mechanical Engineering, Atlanta, Georgia, United States
| | - Heechul Yoon
- Georgia Institute of Technology, School of Electrical and Computer Engineering, Atlanta, Georgia, United States
| | - Stanislav Emelianov
- Georgia Institute of Technology, Parker H. Petit Institute for Bioengineering and Bioscience, Atlanta, Georgia, United States
- Georgia Institute of Technology, School of Electrical and Computer Engineering, Atlanta, Georgia, United States
- Emory University School of Medicine and Georgia Institute of Technology, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
| |
Collapse
|
8
|
Hochuli R, An L, Beard PC, Cox BT. Estimating blood oxygenation from photoacoustic images: can a simple linear spectroscopic inversion ever work? JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-13. [PMID: 31849203 PMCID: PMC7005536 DOI: 10.1117/1.jbo.24.12.121914] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/21/2019] [Indexed: 05/07/2023]
Abstract
Linear spectroscopic inversions, in which photoacoustic amplitudes are assumed to be directly proportional to absorption coefficients, are widely used in photoacoustic imaging to estimate blood oxygen saturation because of their simplicity. Unfortunately, they do not account for the spatially varying wavelength-dependence of the light fluence within the tissue, which introduces "spectral coloring," a potentially significant source of error. However, accurately correcting for spectral coloring is challenging, so we investigated whether there are conditions, e.g., sets of wavelengths, where it is possible to ignore the spectral coloring and still obtain accurate oxygenation measurements using linear inversions. Accurate estimates of oxygenation can be obtained when the wavelengths are chosen to (i) minimize spectral coloring, (ii) avoid ill-conditioning, and (iii) maintain a sufficiently high signal-to-noise ratio (SNR) for the estimates to be meaningful. It is not obvious which wavelengths will satisfy these conditions, and they are very likely to vary for different imaging scenarios, making it difficult to find general rules. Through the use of numerical simulations, we isolated the effect of spectral coloring from sources of experimental error. It was shown that using wavelengths between 500 nm and 1000 nm yields inaccurate estimates of oxygenation and that careful selection of wavelengths in the 620- to 920-nm range can yield more accurate oxygenation values. However, this is only achievable with a good prior estimate of the true oxygenation. Even in this idealized case, it was shown that considerable care must be exercised over the choice of wavelengths when using linear spectroscopic inversions to obtain accurate estimates of blood oxygenation. This suggests that for a particular imaging scenario, obtaining accurate and reliable oxygenation estimates using linear spectroscopic inversions requires careful modeling or experimental studies of that scenario, taking account of the instrumentation, tissue anatomy, likely sO2 range, and image formation process.
Collapse
Affiliation(s)
- Roman Hochuli
- University College London, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
| | - Lu An
- University College London, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
| | - Paul C. Beard
- University College London, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
| | - Benjamin T. Cox
- University College London, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
- Address all correspondence to Benjamin T. Cox, E-mail:
| |
Collapse
|
9
|
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: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [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.
Collapse
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
| |
Collapse
|
10
|
Liu C, Liang Y, Wang L. Optical-resolution photoacoustic microscopy of oxygen saturation with nonlinear compensation. BIOMEDICAL OPTICS EXPRESS 2019; 10:3061-3069. [PMID: 31259074 PMCID: PMC6583336 DOI: 10.1364/boe.10.003061] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/16/2019] [Accepted: 05/19/2019] [Indexed: 05/02/2023]
Abstract
Optical-resolution photoacoustic microscopy (OR-PAM) of oxygen saturation (sO2) offers high-resolution functional information on living tissue. Limited by the availability of high-speed multi-wavelength lasers, most OR-PAM systems use wavelengths around 532nm. Blood has high absorption coefficients in this spectrum, which may cause absorption saturation and induce systematic errors in sO2 imaging. Here, we present nonlinear OR-PAM that compensates for the absorption saturation in sO2 imaging. We model the absorption saturation at different absorption coefficients and ultrasonic bandwidths. To compensate for the absorption saturation, we develop an OR-PAM system with three optical wavelengths and implement a nonlinear algorithm to compute sO2. Phantom experiments on bovine blood validate that the nonlinear OR-PAM can improve the sO2 accuracy by up to 0.13 for fully oxygenated blood. In vivo sO2 imaging has been conducted in the mouse ear. The nonlinear sO2 results agree with the normal physiological values. These results show that the absorption saturation effect can be compensated for in nonlinear OR-PAM, which improves the accuracy of functional photoacoustic imaging.
Collapse
Affiliation(s)
- Chao Liu
- Department of Biomedical Engineering, City University of Hong Kong, 83 Tat Chee Ave, Kowloon, Hong Kong SAR, China
- City University of Hong Kong Shenzhen Research Institute, Yuexing Yi Dao, Nanshan District, China
| | - Yizhi Liang
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou 510632, China
| | - Lidai Wang
- Department of Biomedical Engineering, City University of Hong Kong, 83 Tat Chee Ave, Kowloon, Hong Kong SAR, China
- City University of Hong Kong Shenzhen Research Institute, Yuexing Yi Dao, Nanshan District, China
| |
Collapse
|
11
|
Ntziachristos V, Pleitez MA, Aime S, Brindle KM. Emerging Technologies to Image Tissue Metabolism. Cell Metab 2019; 29:518-538. [PMID: 30269982 DOI: 10.1016/j.cmet.2018.09.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 07/24/2018] [Accepted: 09/02/2018] [Indexed: 12/19/2022]
Abstract
Due to the implication of altered metabolism in a large spectrum of tissue function and disease, assessment of metabolic processes becomes essential in managing health. In this regard, imaging can play a critical role in allowing observation of biochemical and physiological processes. Nuclear imaging methods, in particular positron emission tomography, have been widely employed for imaging metabolism but are mainly limited by the use of ionizing radiation and the sensing of only one parameter at each scanning session. Observations in healthy individuals or longitudinal studies of disease could markedly benefit from non-ionizing, multi-parameter imaging methods. We therefore focus this review on progress with the non-ionizing radiation methods of MRI, hyperpolarized magnetic resonance and magnetic resonance spectroscopy, chemical exchange saturation transfer, and emerging optoacoustic (photoacoustic) imaging. We also briefly discuss the role of nuclear and optical imaging methods for research and clinical protocols.
Collapse
Affiliation(s)
- Vasilis Ntziachristos
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg 85764, Germany; Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Ismaningerstr. 22, Munich 81675, Germany.
| | - Miguel A Pleitez
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg 85764, Germany; Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Ismaningerstr. 22, Munich 81675, Germany
| | - Silvio Aime
- Molecular Imaging Center, Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin 10126, Italy
| | - Kevin M Brindle
- Department of Biochemistry, University of Cambridge, Old Addenbrooke's Site, Cambridge CB2 1GA, UK; Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK
| |
Collapse
|
12
|
Reber J, Willershäuser M, Karlas A, Paul-Yuan K, Diot G, Franz D, Fromme T, Ovsepian SV, Bézière N, Dubikovskaya E, Karampinos DC, Holzapfel C, Hauner H, Klingenspor M, Ntziachristos V. Non-invasive Measurement of Brown Fat Metabolism Based on Optoacoustic Imaging of Hemoglobin Gradients. Cell Metab 2018. [PMID: 29514074 DOI: 10.1016/j.cmet.2018.02.002] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Metabolism is a fundamental process of life. However, non-invasive measurement of local tissue metabolism is limited today by a deficiency in adequate tools for in vivo observations. We designed a multi-modular platform that explored the relation between local tissue oxygen consumption, determined by label-free optoacoustic measurements of hemoglobin, and concurrent indirect calorimetry obtained during metabolic activation of brown adipose tissue (BAT). By studying mice and humans, we show how video-rate handheld multi-spectral optoacoustic tomography (MSOT) in the 700-970 nm spectral range enables non-invasive imaging of BAT activation, consistent with positron emission tomography findings. Moreover, we observe BAT composition differences between healthy and diabetic tissues. The study consolidates hemoglobin as a principal label-free biomarker for longitudinal non-invasive imaging of BAT morphology and bioenergetics in situ. We also resolve water and fat components in volunteers, and contrast MSOT readouts with magnetic resonance imaging data.
Collapse
Affiliation(s)
- Josefine Reber
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany; Chair for Biological Imaging, Technical University of Munich, Munich, Germany
| | - Monja Willershäuser
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany; EKFZ - Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising, Germany; ZIEL - Institute for Food and Health, Technical University of Munich, Freising, Germany
| | - Angelos Karlas
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany; Chair for Biological Imaging, Technical University of Munich, Munich, Germany
| | - Korbinian Paul-Yuan
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany; Chair for Biological Imaging, Technical University of Munich, Munich, Germany
| | - Gael Diot
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany; Chair for Biological Imaging, Technical University of Munich, Munich, Germany
| | - Daniela Franz
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Tobias Fromme
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany; EKFZ - Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising, Germany
| | - Saak V Ovsepian
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany; Chair for Biological Imaging, Technical University of Munich, Munich, Germany
| | - Nicolas Bézière
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany; Chair for Biological Imaging, Technical University of Munich, Munich, Germany
| | - Elena Dubikovskaya
- Department of Chemistry, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | - Dimitrios C Karampinos
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Christina Holzapfel
- Institute for Nutritional Medicine, School of Medicine, Technical University of Munich, Munich, Germany
| | - Hans Hauner
- EKFZ - Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising, Germany; Institute for Nutritional Medicine, School of Medicine, Technical University of Munich, Munich, Germany
| | - Martin Klingenspor
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany; EKFZ - Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising, Germany; ZIEL - Institute for Food and Health, Technical University of Munich, Freising, Germany
| | - Vasilis Ntziachristos
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany; Chair for Biological Imaging, Technical University of Munich, Munich, Germany.
| |
Collapse
|
13
|
Sivasubramanian K, Periyasamy V, Pramanik M. Non-invasive sentinel lymph node mapping and needle guidance using clinical handheld photoacoustic imaging system in small animal. JOURNAL OF BIOPHOTONICS 2018; 11:e201700061. [PMID: 28700132 DOI: 10.1002/jbio.201700061] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/27/2017] [Accepted: 05/25/2017] [Indexed: 05/20/2023]
Abstract
Translating photoacoustic imaging (PAI) into clinical setup is a challenge. Handheld clinical real-time PAI systems are not common. In this work, we report an integrated photoacoustic (PA) and clinical ultrasound imaging system by combining light delivery with the ultrasound probe for sentinel lymph node imaging and needle guidance in small animal. The open access clinical ultrasound platform allows seamless integration of PAI resulting in the development of handheld real-time PAI probe. Both methylene blue and indocyanine green were used for mapping the sentinel lymph node using 675 and 690 nm wavelength illuminations, respectively. Additionally, needle guidance with combined ultrasound and PAI was demonstrated using this imaging system. Up to 1.5 cm imaging depth was observed with a 10 Hz laser at an imaging frame rate of 5 frames per second, which is sufficient for future translation into human sentinel lymph node imaging and needle guidance for fine needle aspiration biopsy.
Collapse
Affiliation(s)
| | - Vijitha Periyasamy
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
| | - Manojit Pramanik
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
| |
Collapse
|
14
|
Karlas A, Reber J, Liapis E, Paul-Yuan K, Ntziachristos V. Multispectral Optoacoustic Tomography of Brown Adipose Tissue. Handb Exp Pharmacol 2018; 251:325-336. [PMID: 29896652 DOI: 10.1007/164_2018_141] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
MSOT has revolutionized biomedical imaging because it allows anatomical, functional, and molecular imaging of deep tissues in vivo in an entirely noninvasive, label-free, and real-time manner. This imaging modality works by pulsing light onto tissue, triggering the production of acoustic waves, which can be collected and reconstructed to provide high-resolution images of features as deep as several centimeters below the body surface. Advances in hardware and software continue to bring MSOT closer to clinical translation. Most recently, a clinical handheld MSOT system has been used to image brown fat tissue (BAT) and its metabolic activity by directly resolving the spectral signatures of hemoglobin and lipids. This opens up new possibilities for studying BAT physiology and its role in metabolic disease without the need to inject animals or humans with contrast agents. In this chapter, we overview how MSOT works and how it has been implemented in preclinical and clinical contexts. We focus on our recent work using MSOT to image BAT in resting and activated states both in mice and humans.
Collapse
Affiliation(s)
- Angelos Karlas
- Chair of Biological Imaging, Technical University Munich, Munich, Germany
- Institute of Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany
| | - Josefine Reber
- Chair of Biological Imaging, Technical University Munich, Munich, Germany
- Institute of Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany
| | - Evangelos Liapis
- Chair of Biological Imaging, Technical University Munich, Munich, Germany
- Institute of Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany
| | - Korbinian Paul-Yuan
- Chair of Biological Imaging, Technical University Munich, Munich, Germany
- Institute of Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany
| | - Vasilis Ntziachristos
- Chair of Biological Imaging, Technical University Munich, Munich, Germany.
- Institute of Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany.
| |
Collapse
|
15
|
Zheng PP, Li J, Kros JM. Breakthroughs in modern cancer therapy and elusive cardiotoxicity: Critical research-practice gaps, challenges, and insights. Med Res Rev 2017; 38:325-376. [PMID: 28862319 PMCID: PMC5763363 DOI: 10.1002/med.21463] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 07/14/2017] [Accepted: 07/15/2017] [Indexed: 12/16/2022]
Abstract
To date, five cancer treatment modalities have been defined. The three traditional modalities of cancer treatment are surgery, radiotherapy, and conventional chemotherapy, and the two modern modalities include molecularly targeted therapy (the fourth modality) and immunotherapy (the fifth modality). The cardiotoxicity associated with conventional chemotherapy and radiotherapy is well known. Similar adverse cardiac events are resurging with the fourth modality. Aside from the conventional and newer targeted agents, even the most newly developed, immune‐based therapeutic modalities of anticancer treatment (the fifth modality), e.g., immune checkpoint inhibitors and chimeric antigen receptor (CAR) T‐cell therapy, have unfortunately led to potentially lethal cardiotoxicity in patients. Cardiac complications represent unresolved and potentially life‐threatening conditions in cancer survivors, while effective clinical management remains quite challenging. As a consequence, morbidity and mortality related to cardiac complications now threaten to offset some favorable benefits of modern cancer treatments in cancer‐related survival, regardless of the oncologic prognosis. This review focuses on identifying critical research‐practice gaps, addressing real‐world challenges and pinpointing real‐time insights in general terms under the context of clinical cardiotoxicity induced by the fourth and fifth modalities of cancer treatment. The information ranges from basic science to clinical management in the field of cardio‐oncology and crosses the interface between oncology and onco‐pharmacology. The complexity of the ongoing clinical problem is addressed at different levels. A better understanding of these research‐practice gaps may advance research initiatives on the development of mechanism‐based diagnoses and treatments for the effective clinical management of cardiotoxicity.
Collapse
Affiliation(s)
- Ping-Pin Zheng
- Cardio-Oncology Research Group, Erasmus Medical Center, Rotterdam, the Netherlands.,Department of Pathology, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Jin Li
- Department of Oncology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Johan M Kros
- Department of Pathology, Erasmus Medical Center, Rotterdam, the Netherlands
| |
Collapse
|
16
|
Liang Y, Jin L, Guan BO, Wang L. 2 MHz multi-wavelength pulsed laser for functional photoacoustic microscopy. OPTICS LETTERS 2017; 42:1452-1455. [PMID: 28362790 DOI: 10.1364/ol.42.001452] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Fast functional photoacoustic microscopy requires multi-wavelength pulsed laser sources with high pulse repetition rates, short wavelength switching time, and sufficient pulse energies. Here, we report the development of a stimulated-Raman-scattering-based multi-wavelength pulsed laser source for fast functional photoacoustic imaging. The new laser source is pumped with a 532 nm 1 MHz pulsed laser. The 532 nm laser beam is split into two: one pumps a 5 m optical fiber to excite a 558 nm wavelength via stimulated Raman scattering; the other goes through a 50 m optical fiber to delay the 532 nm pulse by 220 ns. The two beams are combined and coupled into an optical fiber for photoacoustic excitation. As a result, the new laser source can generate 2 million pulses per second, switch wavelengths in 220 ns, and provide hundreds of nanojoules pulse energy for each wavelength. Using this laser source, we demonstrate optical-resolution photoacoustic imaging of microvascular structures and oxygen saturation in the mouse ear. The ultrashort wavelength switching time enables oxygen saturation imaging of flowing red blood cells, which is valuable for high-resolution functional imaging.
Collapse
|
17
|
Sivasubramanian K, Periyasamy V, Wen KK, Pramanik M. Optimizing light delivery through fiber bundle in photoacoustic imaging with clinical ultrasound system: Monte Carlo simulation and experimental validation. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:41008. [PMID: 27997016 DOI: 10.1117/1.jbo.22.4.041008] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Accepted: 11/28/2016] [Indexed: 05/04/2023]
Abstract
Translating photoacoustic (PA) imaging into clinical setup is a challenge. We report an integrated PA and ultrasound imaging system by combining the light delivery to the tissue with the ultrasound probe. First, Monte Carlo simulations were run to study the variation in absorbance within tissue for different angles of illumination, fiber-to-probe distance (FPD), and fiber-to-tissue distance (FTD). This is followed by simulation for different depths of the embedded sphere (object of interest). Several probe holders were designed for different light launching angles. Phantoms were developed to mimic a sentinel lymph node imaging scenario. It was observed that, for shallower imaging depths, the variation in signal-to-noise ratio (SNR) values could be as high as 100% depending on the angle of illumination at a fixed FPD and FTD. Results confirm that different light illumination angles are required for different imaging depths to get the highest SNR PA images. The results also validate that one can use Monte Carlo simulation as a tool to optimize the probe holder design depending on the imaging needs. This eliminates a trial-and-error approach generally used for designing a probe holder.
Collapse
Affiliation(s)
- Kathyayini Sivasubramanian
- Nanyang Technological University, School of Chemical and Biomedical Engineering, 62 Nanyang Drive, Singapore 637459, Singapore
| | - Vijitha Periyasamy
- Nanyang Technological University, School of Chemical and Biomedical Engineering, 62 Nanyang Drive, Singapore 637459, Singapore
| | - Kew Kok Wen
- Nanyang Technological University, School of Chemical and Biomedical Engineering, 62 Nanyang Drive, Singapore 637459, Singapore
| | - Manojit Pramanik
- Nanyang Technological University, School of Chemical and Biomedical Engineering, 62 Nanyang Drive, Singapore 637459, Singapore
| |
Collapse
|
18
|
Bhatt M, Acharya A, Yalavarthy PK. Computationally efficient error estimate for evaluation of regularization in photoacoustic tomography. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:106002. [PMID: 27762422 DOI: 10.1117/1.jbo.21.10.106002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 09/14/2016] [Indexed: 05/20/2023]
Abstract
The model-based image reconstruction techniques for photoacoustic (PA) tomography require an explicit regularization. An error estimate (?2) minimization-based approach was proposed and developed for the determination of a regularization parameter for PA imaging. The regularization was used within Lanczos bidiagonalization framework, which provides the advantage of dimensionality reduction for a large system of equations. It was shown that the proposed method is computationally faster than the state-of-the-art techniques and provides similar performance in terms of quantitative accuracy in reconstructed images. It was also shown that the error estimate (?2) can also be utilized in determining a suitable regularization parameter for other popular techniques such as Tikhonov, exponential, and nonsmooth (?1 and total variation norm based) regularization methods.
Collapse
Affiliation(s)
- Manish Bhatt
- Indian Institute of Science, Medical Imaging Group, Department of Computational and Data Sciences, C V Raman Avenue, Bengaluru 560012, India
| | - Atithi Acharya
- Indian Institute of Science, Medical Imaging Group, Department of Computational and Data Sciences, C V Raman Avenue, Bengaluru 560012, India
| | - Phaneendra K Yalavarthy
- Indian Institute of Science, Medical Imaging Group, Department of Computational and Data Sciences, C V Raman Avenue, Bengaluru 560012, India
| |
Collapse
|
19
|
Sivasubramanian K, Pramanik M. High frame rate photoacoustic imaging at 7000 frames per second using clinical ultrasound system. BIOMEDICAL OPTICS EXPRESS 2016; 7:312-23. [PMID: 26977342 PMCID: PMC4771451 DOI: 10.1364/boe.7.000312] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 12/22/2015] [Accepted: 12/23/2015] [Indexed: 05/02/2023]
Abstract
Photoacoustic tomography, a hybrid imaging modality combining optical and ultrasound imaging, is gaining attention in the field of medical imaging. Typically, a Q-switched Nd:YAG laser is used to excite the tissue and generate photoacoustic signals. But, such photoacoustic imaging systems are difficult to translate into clinical applications owing to their high cost, bulky size often requiring an optical table to house such lasers. Moreover, the low pulse repetition rate of few tens of hertz prevents them from being used in high frame rate photoacoustic imaging. In this work, we have demonstrated up to 7000 Hz photoacoustic imaging (B-mode) and measured the flow rate of a fast moving object. We used a ~140 nanosecond pulsed laser diode as an excitation source and a clinical ultrasound imaging system to capture and display the photoacoustic images. The excitation laser is ~803 nm in wavelength with ~1.4 mJ energy per pulse. So far, the reported 2-dimensional photoacoustic B-scan imaging is only a few tens of frames per second using a clinical ultrasound system. Therefore, this is the first report on 2-dimensional photoacoustic B-scan imaging with 7000 frames per second. We have demonstrated phantom imaging to view and measure the flow rate of ink solution inside a tube. This fast photoacoustic imaging can be useful for various clinical applications including cardiac related problems, where the blood flow rate is quite high, or other dynamic studies.
Collapse
Affiliation(s)
| | - Manojit Pramanik
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 637459 Singapore
| |
Collapse
|