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Nie S, Yin G, Li P, Guo J. Optimization on artifacts in photoacoustic images based on spectrum analyses and signal extraction. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2024; 156:503-510. [PMID: 39013038 DOI: 10.1121/10.0027934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 06/28/2024] [Indexed: 07/18/2024]
Abstract
Photoacoustic (PA) imaging is a promising technology for functional imaging of biological tissues, offering optical contrast and acoustic penetration depth. However, the presence of signal aliasing from multiple PA sources within the same imaging object can introduce artifacts and significantly impact the quality of the PA tomographic images. In this study, an optimized method is proposed to suppress these artifacts and enhance image quality effectively. By leveraging signal time-frequency spectrum, signals from each PA source can be extracted. Subsequently, the images are reconstructed using these extracted signals and fused together to obtain an optimized image. To verify this proposed method, PA imaging experiments were conducted on two phantoms and two in vitro samples and the distribution relative error and root mean square error of the images obtained through conventional and optimized methods were calculated. The results demonstrate that the proposed method successfully suppresses the artifacts and substantially improves the image quality.
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Affiliation(s)
- Shibo Nie
- Key Laboratory of Ultrasound of Shaanxi Province, School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710119, China
| | - Guanjun Yin
- Key Laboratory of Ultrasound of Shaanxi Province, School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710119, China
| | - Pan Li
- School of Physics and Electrical Engineering, Weinan Normal University, Wei'Nan 714099, China
| | - Jianzhong Guo
- Key Laboratory of Ultrasound of Shaanxi Province, School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710119, China
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2
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Vogt WC, Wear KA, Pfefer TJ. Phantoms for evaluating the impact of skin pigmentation on photoacoustic imaging and oximetry performance. BIOMEDICAL OPTICS EXPRESS 2023; 14:5735-5748. [PMID: 38021140 PMCID: PMC10659791 DOI: 10.1364/boe.501950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/25/2023] [Accepted: 09/11/2023] [Indexed: 12/01/2023]
Abstract
Recent reports have raised concerns of potential racial disparities in performance of optical oximetry technologies. To investigate how variable epidermal melanin content affects performance of photoacoustic imaging (PAI) devices, we developed plastisol phantoms combining swappable skin-mimicking layers with a breast phantom containing either India ink or blood adjusted to 50-100% SO2 using sodium dithionite. Increasing skin pigmentation decreased maximum imaging depth by up to 25%, enhanced image clutter, and increased root-mean-square error in SO2 from 8.0 to 17.6% due to signal attenuation and spectral coloring effects. This phantom tool can aid in evaluating PAI device robustness to ensure high performance in all patients.
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Affiliation(s)
- William C. Vogt
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA
| | - Keith A. Wear
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA
| | - T. Joshua Pfefer
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA
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3
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Hacker L, Brown EL, Lefebvre TL, Sweeney PW, Bohndiek SE. Performance evaluation of mesoscopic photoacoustic imaging. PHOTOACOUSTICS 2023; 31:100505. [PMID: 37214427 PMCID: PMC10199419 DOI: 10.1016/j.pacs.2023.100505] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/05/2023] [Accepted: 05/05/2023] [Indexed: 05/24/2023]
Abstract
Photoacoustic mesoscopy visualises vascular architecture at high-resolution up to ~3 mm depth. Despite promise in preclinical and clinical imaging studies, with applications in oncology and dermatology, the accuracy and precision of photoacoustic mesoscopy is not well established. Here, we evaluate a commercial photoacoustic mesoscopy system for imaging vascular structures. Typical artefact types are first highlighted and limitations due to non-isotropic illumination and detection are evaluated with respect to rotation, angularity, and depth of the target. Then, using tailored phantoms and mouse models, we investigate system precision, showing coefficients of variation (COV) between repeated scans [short term (1 h): COV= 1.2%; long term (25 days): COV= 9.6%], from target repositioning (without: COV=1.2%, with: COV=4.1%), or from varying in vivo user experience (experienced: COV=15.9%, unexperienced: COV=20.2%). Our findings show robustness of the technique, but also underscore general challenges of limited-view photoacoustic systems in accurately imaging vessel-like structures, thereby guiding users when interpreting biologically-relevant information.
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Affiliation(s)
- Lina Hacker
- Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
- Cancer Research UK Cambridge Institute, University of Cambridge, Robinson Way, Cambridge CB2 0RE, UK
| | - Emma L. Brown
- Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
- Cancer Research UK Cambridge Institute, University of Cambridge, Robinson Way, Cambridge CB2 0RE, UK
| | - Thierry L. Lefebvre
- Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
- Cancer Research UK Cambridge Institute, University of Cambridge, Robinson Way, Cambridge CB2 0RE, UK
| | - Paul W. Sweeney
- Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
- Cancer Research UK Cambridge Institute, University of Cambridge, Robinson Way, Cambridge CB2 0RE, UK
| | - Sarah E. Bohndiek
- Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
- Cancer Research UK Cambridge Institute, University of Cambridge, Robinson Way, Cambridge CB2 0RE, UK
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4
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Van Heumen S, Riksen JJ, Singh MKA, Van Soest G, Vasilic D. LED-based photoacoustic imaging for preoperative visualization of lymphatic vessels in patients with secondary limb lymphedema. PHOTOACOUSTICS 2023; 29:100446. [PMID: 36632606 PMCID: PMC9826814 DOI: 10.1016/j.pacs.2022.100446] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/16/2022] [Accepted: 12/27/2022] [Indexed: 06/17/2023]
Abstract
Lymphedema is the accumulation of protein-rich fluid in the interstitium (i.e., dermal backflow (DBF)). Preoperative imaging of the lymphatic vessels is a prerequisite for lymphovenous bypass surgical planning. We investigated the visualization of lymphatic vessels and veins using light-emitting diode (LED)-based photoacoustic imaging (PAI). Indocyanine-green mediated near-infrared fluorescence lymphography (NIRF-L) was done in fifteen patients with secondary limb lymphedema. Photoacoustic images were acquired in locations where lymphatic vessels and DBF were observed with NIRF-L. We demonstrated that LED-based PAI can visualize and differentiate lymphatic vessels and veins even in the presence of DBF. We observed lymphatic and blood vessels up to depths of 8.3 and 8.6 mm, respectively. Superficial lymphatic vessels and veins can be visualized using LED-based PAI even in the presence of DBF showing the potential for pre-operative assessment. Further development of the technique is needed to improve its usability in clinical settings.
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Affiliation(s)
- Saskia Van Heumen
- Department of Plastic and Reconstructive Surgery, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
- Department of Cardiology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Jonas J.M. Riksen
- Department of Cardiology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | | | - Gijs Van Soest
- Department of Cardiology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Dalibor Vasilic
- Department of Plastic and Reconstructive Surgery, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
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5
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Palma-Chavez J, Wear KA, Mantri Y, Jokerst JV, Vogt WC. Photoacoustic imaging phantoms for assessment of object detectability and boundary buildup artifacts. PHOTOACOUSTICS 2022; 26:100348. [PMID: 35360521 PMCID: PMC8960980 DOI: 10.1016/j.pacs.2022.100348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 02/18/2022] [Accepted: 03/17/2022] [Indexed: 05/05/2023]
Abstract
Standardized phantoms and test methods are needed to accelerate clinical translation of emerging photoacoustic imaging (PAI) devices. Evaluating object detectability in PAI is challenging due to variations in target morphology and artifacts including boundary buildup. Here we introduce breast fat and parenchyma tissue-mimicking materials based on emulsions of silicone oil and ethylene glycol in polyacrylamide hydrogel. 3D-printed molds were used to fabricate solid target inclusions that produced more filled-in appearance than traditional PAI phantoms. Phantoms were used to assess understudied image quality characteristics (IQCs) of three PAI systems. Object detectability was characterized vs. target diameter, absorption coefficient, and depth. Boundary buildup was quantified by target core/boundary ratio, which was higher in transducers with lower center frequency. Target diameter measurement accuracy was also size-dependent and improved with increasing transducer frequency. These phantoms enable evaluation of multiple key IQCs and may support development of comprehensive standardized test methods for PAI devices.
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Affiliation(s)
- Jorge Palma-Chavez
- Department of NanoEngineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Keith A. Wear
- Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Yash Mantri
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jesse V. Jokerst
- Department of NanoEngineering, University of California San Diego, La Jolla, CA 92093, USA
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA
- Material Science Program, University of California San Diego, La Jolla, CA 92093, USA
- Corresponding author at: Department of NanoEngineering, University of California San Diego, La Jolla, CA 92093, USA.
| | - William C. Vogt
- Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, MD 20993, USA
- Corresponding author.
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Sun Z, Zhang X. Suppression of acoustic reflection artifact in endoscopic photoacoustic tomographic images based on approximation of ideal signals. Technol Health Care 2022; 30:201-214. [PMID: 35124597 PMCID: PMC9028649 DOI: 10.3233/thc-228019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND: In endoscopic photoacoustic tomography (EPAT), the photoacoustically induced ultrasonic wave reflects at tissue boundaries due to the acoustic inhomogeneity of the imaged tissue, resulting in reflection artifacts (RAs) in the reconstructed images. OBJECTIVE: To suppress RAs in EPAT image reconstruction for improving the image quality. METHODS: A method was presented to render the cross-sectional images of the optical absorption with reduced RAs from acoustic measurements. The ideal photoacoustic signal was recovered from acoustic signals collected by the detector through solving a least square problem. Then, high-quality images of the optical absorption distribution were reconstructed from the ideal signal. RESULTS: The results demonstrated the improvement in the quality of the images rendered by this method in comparison with the conventional back-projection (BP) reconstructions. Compared with the short lag spatial coherence (SLSC) method, the peak signal-to-noise ratio (PSNR), normalized mean square absolute distance (NMSAD), and structural similarity (SSIM) were improved by up to 8%, 20%, and 5%, respectively. CONCLUSIONS: This method was capable of rendering images displaying the complex tissue types with reduced RAs and lower computational burden in comparison with previously developed methods.
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Affiliation(s)
- Zheng Sun
- Corresponding author: Zheng Sun, Department of Electronic and Communication Engineering, North China Electric Power University, P.O. Box 21, No. 619 Yonghua North Street, Baoding, Hebei 071003, China. Tel.: +86 15930929260; Fax: +86 3127522272; E-mail:
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7
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Kuriakose M, Borden MA. Microbubbles and Nanodrops for photoacoustic tomography. Curr Opin Colloid Interface Sci 2021. [DOI: 10.1016/j.cocis.2021.101464] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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8
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Palma-Chavez J, Pfefer TJ, Agrawal A, Jokerst JV, Vogt WC. Review of consensus test methods in medical imaging and current practices in photoacoustic image quality assessment. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-210176VSSR. [PMID: 34510850 PMCID: PMC8434148 DOI: 10.1117/1.jbo.26.9.090901] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 08/17/2021] [Indexed: 05/06/2023]
Abstract
SIGNIFICANCE Photoacoustic imaging (PAI) is a powerful emerging technology with broad clinical applications, but consensus test methods are needed to standardize performance evaluation and accelerate translation. AIM To review consensus image quality test methods for mature imaging modalities [ultrasound, magnetic resonance imaging (MRI), x-ray CT, and x-ray mammography], identify best practices in phantom design and testing procedures, and compare against current practices in PAI phantom testing. APPROACH We reviewed scientific papers, international standards, clinical accreditation guidelines, and professional society recommendations describing medical image quality test methods. Observations are organized by image quality characteristics (IQCs), including spatial resolution, geometric accuracy, imaging depth, uniformity, sensitivity, low-contrast detectability, and artifacts. RESULTS Consensus documents typically prescribed phantom geometry and material property requirements, as well as specific data acquisition and analysis protocols to optimize test consistency and reproducibility. While these documents considered a wide array of IQCs, reported PAI phantom testing focused heavily on in-plane resolution, depth of visualization, and sensitivity. Understudied IQCs that merit further consideration include out-of-plane resolution, geometric accuracy, uniformity, low-contrast detectability, and co-registration accuracy. CONCLUSIONS Available medical image quality standards provide a blueprint for establishing consensus best practices for photoacoustic image quality assessment and thus hastening PAI technology advancement, translation, and clinical adoption.
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Affiliation(s)
- Jorge Palma-Chavez
- University of California San Diego, Department of NanoEngineering, La Jolla, California, United States
| | - T. Joshua Pfefer
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, United States
| | - Anant Agrawal
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, United States
| | - Jesse V. Jokerst
- University of California San Diego, Department of NanoEngineering, La Jolla, California, United States
- University of California San Diego, Department of Radiology, La Jolla, California, United States
- University of California San Diego, Materials Science and Engineering Program, La Jolla, California, United States
| | - William C. Vogt
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, United States
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9
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Jeng GS, Li ML, Kim M, Yoon SJ, Pitre JJ, Li DS, Pelivanov I, O’Donnell M. Real-time interleaved spectroscopic photoacoustic and ultrasound (PAUS) scanning with simultaneous fluence compensation and motion correction. Nat Commun 2021; 12:716. [PMID: 33514737 PMCID: PMC7846772 DOI: 10.1038/s41467-021-20947-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 12/22/2020] [Indexed: 02/06/2023] Open
Abstract
For over two decades photoacoustic imaging has been tested clinically, but successful human trials have been limited. To enable quantitative clinical spectroscopy, the fundamental issues of wavelength-dependent fluence variations and inter-wavelength motion must be overcome. Here we propose a real-time, spectroscopic photoacoustic/ultrasound (PAUS) imaging approach using a compact, 1-kHz rate wavelength-tunable laser. Instead of illuminating tissue over a large area, the fiber-optic delivery system surrounding an US array sequentially scans a narrow laser beam, with partial PA image reconstruction for each laser pulse. The final image is then formed by coherently summing partial images. This scheme enables (i) automatic compensation for wavelength-dependent fluence variations in spectroscopic PA imaging and (ii) motion correction of spectroscopic PA frames using US speckle tracking in real-time systems. The 50-Hz video rate PAUS system is demonstrated in vivo using a murine model of labelled drug delivery.
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Affiliation(s)
- Geng-Shi Jeng
- grid.34477.330000000122986657Department of Bioengineering, University of Washington, Seattle, WA USA ,grid.260539.b0000 0001 2059 7017Institute of Electronics, National Chiao Tung University, Hsinchu, Taiwan
| | - Meng-Lin Li
- grid.38348.340000 0004 0532 0580Department of Electrical Engineering, National Tsing Hua University, Hsinchu, Taiwan ,grid.38348.340000 0004 0532 0580Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan
| | - MinWoo Kim
- grid.34477.330000000122986657Department of Bioengineering, University of Washington, Seattle, WA USA
| | - Soon Joon Yoon
- grid.34477.330000000122986657Department of Bioengineering, University of Washington, Seattle, WA USA
| | - John J. Pitre
- grid.34477.330000000122986657Department of Bioengineering, University of Washington, Seattle, WA USA
| | - David S. Li
- grid.34477.330000000122986657Department of Chemical Engineering, University of Washington, Seattle, WA USA
| | - Ivan Pelivanov
- grid.34477.330000000122986657Department of Bioengineering, University of Washington, Seattle, WA USA
| | - Matthew O’Donnell
- grid.34477.330000000122986657Department of Bioengineering, University of Washington, Seattle, WA USA
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Nguyen HNY, Steenbergen W. Feasibility of identifying reflection artifacts in photoacoustic imaging using two-wavelength excitation. BIOMEDICAL OPTICS EXPRESS 2020; 11:5745-5759. [PMID: 33149983 PMCID: PMC7587260 DOI: 10.1364/boe.401375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/28/2020] [Accepted: 09/17/2020] [Indexed: 06/11/2023]
Abstract
One of the remaining challenges of bringing photoacoustic imaging to clinics is the occurrence of reflection artifacts. Previously, we proposed a method using multi-wavelength excitation to identify and remove the RAs. However, this method requires at least 3 wavelengths. Here we improve the method further by reducing the required number of wavelengths to 2. We experimentally demonstrate this new method and compare it with the previous one. Results show that this new method holds great feasibility for identifying reflection artifacts in addition to preserving all advantages of the previous method.
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11
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Lediju Bell MA. Photoacoustic imaging for surgical guidance: Principles, applications, and outlook. JOURNAL OF APPLIED PHYSICS 2020; 128:060904. [PMID: 32817994 PMCID: PMC7428347 DOI: 10.1063/5.0018190] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 07/30/2020] [Indexed: 05/08/2023]
Abstract
Minimally invasive surgeries often require complicated maneuvers and delicate hand-eye coordination and ideally would incorporate "x-ray vision" to see beyond tool tips and underneath tissues prior to making incisions. Photoacoustic imaging has the potential to offer this feature but not with ionizing x-rays. Instead, optical fibers and acoustic receivers enable photoacoustic sensing of major structures-such as blood vessels and nerves-that are otherwise hidden from view. This imaging process is initiated by transmitting laser pulses that illuminate regions of interest, causing thermal expansion and the generation of sound waves that are detectable with conventional ultrasound transducers. The recorded signals are then converted to images through the beamforming process. Photoacoustic imaging may be implemented to both target and avoid blood-rich surgical contents (and in some cases simultaneously or independently visualize optical fiber tips or metallic surgical tool tips) in order to prevent accidental injury and assist device operators during minimally invasive surgeries and interventional procedures. Novel light delivery systems, counterintuitive findings, and robotic integration methods introduced by the Photoacoustic & Ultrasonic Systems Engineering Lab are summarized in this invited Perspective, setting the foundation and rationale for the subsequent discussion of the author's views on possible future directions for this exciting frontier known as photoacoustic-guided surgery.
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Affiliation(s)
- Muyinatu A. Lediju Bell
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
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12
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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.
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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
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Nguyen HNY, Steenbergen W. Reducing artifacts in photoacoustic imaging by using multi-wavelength excitation and transducer displacement. BIOMEDICAL OPTICS EXPRESS 2019; 10:3124-3138. [PMID: 31467773 PMCID: PMC6706045 DOI: 10.1364/boe.10.003124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 05/22/2019] [Accepted: 05/27/2019] [Indexed: 05/06/2023]
Abstract
The occurrence of artifacts is a major challenge in photoacoustic imaging. The artifacts negatively affect the quality and reliability of the images. An approach using multi-wavelength excitation has previously been reported for in-plane artifact identification. Yet, out-of-plane artifacts cannot be tackled with this method. Here we propose a new method using ultrasound transducer array displacement. By displacing the ultrasound transducer array axially, we can de-correlate out-of-plane artifacts with in-plane image features and thus remove them. Combining this new method with the previous one allows us to remove potentially completely both in-plane and out-of-plane artifacts in photoacoustic imaging. We experimentally demonstrate this with experiments in phantoms as well as in vivo.
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Affiliation(s)
- Ho Nhu Y. Nguyen
- Biomedical Photonic Imaging Group, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Wiendelt Steenbergen
- Biomedical Photonic Imaging Group, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
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Sangha GS, Hale NJ, Goergen CJ. Adjustable photoacoustic tomography probe improves light delivery and image quality. PHOTOACOUSTICS 2018; 12:6-13. [PMID: 30175045 PMCID: PMC6118042 DOI: 10.1016/j.pacs.2018.08.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 07/20/2018] [Accepted: 08/09/2018] [Indexed: 05/07/2023]
Abstract
One cause for suboptimal photoacoustic tomography (PAT) penetration depth is attenuation of incident light by soft tissue. To better understand this problem, we investigated the effects of illumination fiber optic bundle geometry on PAT penetration depth and signal-to-noise ratio. An adjustable, motorized PAT probe was used to reduce probe-skin reflection artifacts and improve light distribution in the image acquisition plane by tuning fiber orientation. We validated our motorized PAT probe through Monte Carlo simulations and ex vivo imaging of a tissue mimicking phantom, and in vivo imaging of murine periaortic fat. Overall, our ex vivo results showed a several millimeter improvement in penetration depth and in vivo results showed a >62% increase in lipid signal-to-noise ratio. Our PAT probe also utilized a 7-μm aluminum filter to block in vivo probe-skin reflection artifacts. Together, these findings showed the importance of optimizing illumination geometry to enhance PAT image quality.
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Affiliation(s)
- Gurneet S. Sangha
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Dr., West Lafayette, IN 47907, USA
| | - Nicholas J. Hale
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Dr., West Lafayette, IN 47907, USA
| | - Craig J. Goergen
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Dr., West Lafayette, IN 47907, USA
- Purdue University Center for Cancer Research, Purdue University, 201 S. University St., West Lafayette, IN 47907, USA
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15
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Nguyen HNY, Hussain A, Steenbergen W. Reflection artifact identification in photoacoustic imaging using multi-wavelength excitation. BIOMEDICAL OPTICS EXPRESS 2018; 9:4613-4630. [PMID: 30319890 PMCID: PMC6179390 DOI: 10.1364/boe.9.004613] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/27/2018] [Accepted: 08/27/2018] [Indexed: 05/22/2023]
Abstract
Photoacoustic imaging has been a focus of research for clinical applications owing to its ability for deep visualization with optical absorption contrast. However, there are various technical challenges remaining for this technique to find its place in clinics. One of the challenges is the occurrence of reflection artifacts. The reflection artifacts may lead to image misinterpretation. Here we propose a new method using multiple wavelengths for identifying and removing the reflection artifacts. By imaging the sample with multiple wavelengths, the spectral response of the features in the photoacoustic image is obtained. We assume that the spectral response of the reflection artifact is better correlated with the proper image feature of its corresponding absorber than with other features in the image. Based on this, the reflection artifacts can be identified and removed. Here, we experimentally demonstrated the potential of this method for real-time identification and correction of reflection artifacts in photoacoustic images in phantoms as well as in vivo using a handheld photoacoustic imaging probe.
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Affiliation(s)
- Ho Nhu Y. Nguyen
- Biomedical Photonic Imaging Group, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Altaf Hussain
- Biomedical Photonic Imaging Group, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Wiendelt Steenbergen
- Biomedical Photonic Imaging Group, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
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16
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Petrosyan T, Theodorou M, Bamber J, Frenz M, Jaeger M. Rapid scanning wide-field clutter elimination in epi-optoacoustic imaging using comb LOVIT. PHOTOACOUSTICS 2018; 10:20-30. [PMID: 29755937 PMCID: PMC5945922 DOI: 10.1016/j.pacs.2018.02.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 12/22/2017] [Accepted: 02/13/2018] [Indexed: 05/07/2023]
Abstract
Epi-style optoacoustic (OA) imaging provides flexibility by integrating the irradiation optics and ultrasound receiver, yet clutter generated by optical absorption near the probe obscures deep OA sources. Localised vibration tagging (LOVIT) retrieves OA signal from images that are acquired with and without a preceding ultrasonic pushing beam: Radiation force leads to a phase shift of signals coming from the focal area resulting in their visibility in a difference image, whereas clutter from outside the pushing beam is eliminated. Disadvantages of a single-focus approach are residual clutter from inside the pushing beam above the focus, and time-intensive scanning of the focus to retrieve a large field-of-view. To speed up acquisition, we propose to create multiple foci in parallel, forming comb-shaped ARF patterns. By subtracting OA images obtained with interleaved combs, this technique moreover results in greatly improved clutter reduction in phantoms mimicking optical, acoustic and elastic properties of breast tissue.
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Affiliation(s)
- Tigran Petrosyan
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland
| | - Maria Theodorou
- Joint Department of Physics and CRUK-EPSRC Cancer Imaging Centre, Institute of Cancer Research, and Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey, SM2 5PT, UK
| | - Jeff Bamber
- Joint Department of Physics and CRUK-EPSRC Cancer Imaging Centre, Institute of Cancer Research, and Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey, SM2 5PT, UK
| | - Martin Frenz
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland
| | - Michael Jaeger
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland
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17
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Petrosyan T, Theodorou M, Bamber J, Frenz M, Jaeger M. Rapid scanning wide-field clutter elimination in epi-optoacoustic imaging using comb LOVIT. PHOTOACOUSTICS 2018; 10:20-30. [PMID: 29755937 DOI: 10.1109/ultsym.2017.8092699] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 12/22/2017] [Accepted: 02/13/2018] [Indexed: 05/22/2023]
Abstract
Epi-style optoacoustic (OA) imaging provides flexibility by integrating the irradiation optics and ultrasound receiver, yet clutter generated by optical absorption near the probe obscures deep OA sources. Localised vibration tagging (LOVIT) retrieves OA signal from images that are acquired with and without a preceding ultrasonic pushing beam: Radiation force leads to a phase shift of signals coming from the focal area resulting in their visibility in a difference image, whereas clutter from outside the pushing beam is eliminated. Disadvantages of a single-focus approach are residual clutter from inside the pushing beam above the focus, and time-intensive scanning of the focus to retrieve a large field-of-view. To speed up acquisition, we propose to create multiple foci in parallel, forming comb-shaped ARF patterns. By subtracting OA images obtained with interleaved combs, this technique moreover results in greatly improved clutter reduction in phantoms mimicking optical, acoustic and elastic properties of breast tissue.
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Affiliation(s)
- Tigran Petrosyan
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland
| | - Maria Theodorou
- Joint Department of Physics and CRUK-EPSRC Cancer Imaging Centre, Institute of Cancer Research, and Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey, SM2 5PT, UK
| | - Jeff Bamber
- Joint Department of Physics and CRUK-EPSRC Cancer Imaging Centre, Institute of Cancer Research, and Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey, SM2 5PT, UK
| | - Martin Frenz
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland
| | - Michael Jaeger
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland
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18
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Petrova EV, Brecht HP, Motamedi M, Oraevsky AA, Ermilov SA. In vivo optoacoustic temperature imaging for image-guided cryotherapy of prostate cancer. Phys Med Biol 2018; 63:064002. [PMID: 29480808 DOI: 10.1088/1361-6560/aab241] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The objective of this study is to demonstrate in vivo the feasibility of optoacoustic temperature imaging during cryotherapy of prostate cancer. We developed a preclinical prototype optoacoustic temperature imager that included pulsed optical excitation at a wavelength of 805 nm, a modified clinical transrectal ultrasound probe, a parallel data acquisition system, image processing and visualization software. Cryotherapy of a canine prostate was performed in vivo using a commercial clinical system, Cryocare® CS, with an integrated ultrasound imaging. The universal temperature-dependent optoacoustic response of blood was employed to convert reconstructed optoacoustic images to temperature maps. Optoacoustic imaging of temperature during prostate cryotherapy was performed in the longitudinal view over a region of 30 mm (long) × 10 mm (deep) that covered the rectum, the Denonvilliers fascia, and the posterior portion of the treated gland. The transrectal optoacoustic images showed high-contrast vascularized regions, which were used for quantitative estimation of local temperature profiles. The constructed temperature maps and their temporal dynamics were consistent with the arrangement of the cryoprobe and readouts of the thermal needle sensors. The temporal profiles of the readouts from the thermal needle sensors and the temporal profile estimated from the normalized optoacoustic intensity of the selected vascularized region showed significant resemblance, except for the initial overshoot, that may be explained as a result of the physiological thermoregulatory compensation. The temperature was mapped with errors not exceeding ±2 °C (standard deviation) consistent with the clinical requirements for monitoring cryotherapy of the prostate. In vivo results showed that the optoacoustic temperature imaging is a promising non-invasive technique for real-time imaging of tissue temperature during cryotherapy of prostate cancer, which can be combined with transrectal ultrasound-the current standard for guiding clinical cryotherapy procedure.
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Affiliation(s)
- E V Petrova
- Tomowave Laboratories, Inc., 6550 Mapleridge St, Ste 124, Houston, TX 77081-4629, United States of America. Present address: Department of Medicine, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, United States of America
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19
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Kalkhoran MA, Vray D. Theoretical characterization of annular array as a volumetric optoacoustic ultrasound handheld probe. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-9. [PMID: 29488361 DOI: 10.1117/1.jbo.23.2.025004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 01/25/2018] [Indexed: 06/08/2023]
Abstract
Optoacoustic ultrasound (OPUS) is a promising hybridized technique for simultaneous acquisition of functional and morphological data. The optical specificity of optoacoustic leverages the diagnostic aptitude of ultrasonography beyond anatomy. However, this integration has been rarely practiced for volumetric imaging. The challenge lies in the effective imaging probes that preserve the functionality of both modalities. The potentials of a sparse annular array for volumetric OPUS imaging are theoretically investigated. In order to evaluate and optimize the performance characteristics of the probe, series of analysis in the framework of system model matrix was carried out. The two criteria of voxel crosstalk and eigenanalysis have been employed to unveil information about the spatial sensitivity, aliasing, and number of definable spatial frequency components. Based on these benchmarks, the optimal parameters for volumetric handheld probe are determined. In particular, the number, size, and the arrangement of the elements and overall aperture dimension were investigated. The result of the numerical simulation suggests that the segmented-annular array of 128 negatively focused elements with 1λ × 20λ size, operating at 5-MHz central frequency showcases a good agreement with the physical requirement of both imaging systems. We hypothesize that these features enable a high-throughput volumetric passive/active ultrasonic imaging system with great potential for clinical applications.
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Affiliation(s)
- Mohammad Azizian Kalkhoran
- Université de Lyon, Université Claude Bernard Lyon 1, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, France
| | - Didier Vray
- Université de Lyon, Université Claude Bernard Lyon 1, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, France
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20
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Esenaliev RO. Optoacoustic Monitoring of Physiologic Variables. Front Physiol 2017; 8:1030. [PMID: 29311964 PMCID: PMC5732935 DOI: 10.3389/fphys.2017.01030] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Accepted: 11/28/2017] [Indexed: 11/23/2022] Open
Abstract
Optoacoustic (photoacoustic) technique is a novel diagnostic platform that can be used for noninvasive measurements of physiologic variables, functional imaging, and hemodynamic monitoring. This technique is based on generation and time-resolved detection of optoacoustic (thermoelastic) waves generated in tissue by short optical pulses. This provides probing of tissues and individual blood vessels with high optical contrast and ultrasound spatial resolution. Because the optoacoustic waves carry information on tissue optical and thermophysical properties, detection, and analysis of the optoacoustic waves allow for measurements of physiologic variables with high accuracy and specificity. We proposed to use the optoacoustic technique for monitoring of a number of important physiologic variables including temperature, thermal coagulation, freezing, concentration of molecular dyes, nanoparticles, oxygenation, and hemoglobin concentration. In this review we present origin of contrast and high spatial resolution in these measurements performed with optoacoustic systems developed and built by our group. We summarize data obtained in vitro, in experimental animals, and in humans on monitoring of these physiologic variables. Our data indicate that the optoacoustic technology may be used for monitoring of cerebral blood oxygenation in patients with traumatic brain injury and in neonatal patients, central venous oxygenation monitoring, total hemoglobin concentration monitoring, hematoma detection and characterization, monitoring of temperature, and coagulation and freezing boundaries during thermotherapy.
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Affiliation(s)
- Rinat O Esenaliev
- Laboratory for Optical Sensing and Monitoring, Department of Neuroscience and Cell Biology, Department of Anesthesiology, Center for Biomedical Engineering, University of Texas Medical Branch, Galveston, TX, United States
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21
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Abe H, Shiina T. Visualization of photoacoustic images in a limited-View measuring system using eigenvalues of a photoacoustic transmission matrix. PHOTOACOUSTICS 2017; 8:1-7. [PMID: 28736704 PMCID: PMC5510525 DOI: 10.1016/j.pacs.2017.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 06/15/2017] [Accepted: 06/21/2017] [Indexed: 05/08/2023]
Abstract
Photoacoustic imaging is a unique imaging method that involves extracting information from points at different depths, an advantage of ultrasound imaging, while maintaining functional information, a key feature of conventional photo imaging. This makes it easy to add functional images to ultrasound images by adding a laser pulse source to the conventional ultrasound imaging device and detecting a photo-ultrasound signal via a conventional ultrasound probe. One challenge when using normal one-dimensional (1D) probes and generating photoacoustic images is the limited-view problem, in which artefacts are observed due to the positions of the ultrasound transducers. In this study, we used a photoacoustic transmission matrix (PA-TM) for simulation and performed a verification test using a 1D probe and a phantom. The results confirmed that the eigenvalues of the PA-TM visualized the light absorber itself in the limited-view measurement system, which eliminates reconstruction artefacts and further scattering artefacts, and that visualization is possible by signal intensity amplification through further phase modulation.
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22
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Mercep E, Dean-Ben XL, Razansky D. Combined Pulse-Echo Ultrasound and Multispectral Optoacoustic Tomography With a Multi-Segment Detector Array. IEEE TRANSACTIONS ON MEDICAL IMAGING 2017; 36:2129-2137. [PMID: 28541198 DOI: 10.1109/tmi.2017.2706200] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The high complementarity of ultrasonography and optoacoustic tomography has prompted the development of combined approaches that utilize the same transducer array for detecting both optoacoustic and pulse-echo ultrasound responses from tissues. Yet, due to the fundamentally different physical contrast and image formation mechanisms, the development of detection technology optimally suited for image acquisition in both modalities remains a major challenge. Herein, we introduce a multi-segment detector array approach incorporating array segments of linear and concave geometry to optimally support both ultrasound and optoacoustic image acquisition. The various image rendering strategies are tested and optimized in numerical simulations and calibrated tissue-mimicking phantom experiments. We subsequently demonstrate real-time hybrid optoacoustic ultrasound image acquisition in a healthy volunteer. The new approach enables the acquisition of high-quality anatomical data by both modalities complemented by functional information on blood oxygenation status provided by the multispectral optoacoustic tomography.
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23
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Esenaliev RO. Optoacoustic diagnostic modality: from idea to clinical studies with highly compact laser diode-based systems. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:91512. [PMID: 28444150 PMCID: PMC5404694 DOI: 10.1117/1.jbo.22.9.091512] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 04/10/2017] [Indexed: 05/25/2023]
Abstract
Optoacoustic (photoacoustic) diagnostic modality is a technique that combines high optical contrast and ultrasound spatial resolution. We proposed using the optoacoustic technique for a number of applications, including cancer detection, monitoring of thermotherapy (hyperthermia, coagulation, and freezing), monitoring of cerebral blood oxygenation in patients with traumatic brain injury, neonatal patients, fetuses during late-stage labor, central venous oxygenation monitoring, and total hemoglobin concentration monitoring as well as hematoma detection and characterization. We developed and built optical parametric oscillator-based systems and multiwavelength, fiber-coupled highly compact, laser diode-based systems for optoacoustic imaging, monitoring, and sensing. To provide sufficient output pulse energy, a specially designed fiber-optic system was built and incorporated in ultrasensitive, wideband optoacoustic probes. We performed preclinical and clinical tests of the systems and the optoacoustic probes in backward mode for most of the applications and in forward mode for the breast cancer and cerebral applications. The high pulse energy and repetition rate allowed for rapid data acquisition with high signal-to-noise ratio from cerebral blood vessels, such as the superior sagittal sinus, central veins, and peripheral veins and arteries, as well as from intracranial hematomas. The optoacoustic systems were capable of automatic, real-time, continuous measurements of blood oxygenation in these blood vessels.
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Affiliation(s)
- Rinat O. Esenaliev
- University of Texas Medical Branch, Laboratory for Optical Sensing and Monitoring, Center for Biomedical Engineering, Department of Neuroscience and Cell Biology, Department of Anesthesiology, Galveston, Texas, United States
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24
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Singh MKA, Jaeger M, Frenz M, Steenbergen W. Photoacoustic reflection artifact reduction using photoacoustic-guided focused ultrasound: comparison between plane-wave and element-by-element synthetic backpropagation approach. BIOMEDICAL OPTICS EXPRESS 2017; 8:2245-2260. [PMID: 28736669 PMCID: PMC5516831 DOI: 10.1364/boe.8.002245] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 03/06/2017] [Accepted: 03/13/2017] [Indexed: 05/07/2023]
Abstract
Reflection artifacts caused by acoustic inhomogeneities constitute a major problem in epi-mode biomedical photoacoustic imaging. Photoacoustic transients from the skin and superficial optical absorbers traverse into the tissue and reflect off echogenic structures to generate reflection artifacts. These artifacts cause difficulties in the interpretation of images and reduce contrast and imaging depth. We recently developed a method called PAFUSion (photoacoustic-guided focused ultrasound) to circumvent the problem of reflection artifacts in photoacoustic imaging. We already demonstrated that the photoacoustic signals can be backpropagated using synthetic aperture pulse-echo data for identifying and reducing reflection artifacts in vivo. In this work, we propose an alternative variant of PAFUSion in which synthetic backpropagation of photoacoustic signals is based on multi-angled plane-wave ultrasound measurements. We implemented plane-wave and synthetic aperture PAFUSion in a handheld ultrasound/photoacoustic imaging system and demonstrate reduction of reflection artifacts in phantoms and in vivo measurements on a human finger using both approaches. Our results suggest that, while both approaches are equivalent in terms of artifact reduction efficiency, plane-wave PAFUSion requires less pulse echo acquisitions when the skin absorption is the main cause of reflection artifacts.
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Affiliation(s)
- Mithun Kuniyil Ajith Singh
- Biomedical Photonic Imaging Group, MIRA institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Michael Jaeger
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
| | - Martin Frenz
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
| | - Wiendelt Steenbergen
- Biomedical Photonic Imaging Group, MIRA institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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25
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Hill ER, Xia W, Clarkson MJ, Desjardins AE. Identification and removal of laser-induced noise in photoacoustic imaging using singular value decomposition. BIOMEDICAL OPTICS EXPRESS 2017; 8:68-77. [PMID: 28101402 PMCID: PMC5231316 DOI: 10.1364/boe.8.000068] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 10/28/2016] [Accepted: 11/11/2016] [Indexed: 05/20/2023]
Abstract
Singular value decomposition (SVD) was used to identify and remove laser-induced noise in photoacoustic images acquired with a clinical ultrasound scanner. This noise, which was prominent in the radiofrequency data acquired in parallel from multiple transducer elements, was induced by the excitation light source. It was modelled by truncating the SVD matrices so that only the first few largest singular value components were retained, and subtracted prior to image reconstruction. The dependency of the signal amplitude and the number of the largest singular value components used for noise modeling was investigated for different photoacoustic source geometries. Validation was performed with simulated data and measured noise, and with photoacoustic images acquired from the human forearm and finger in vivo using L14-5/38 and L40-8/12 linear array clinical imaging probes. The use of only one singular value component was found to be sufficient to achieve near-complete removal of laser-induced noise from reconstructed images. This method has strong potential to increase image quality for a wide range of photoacoustic imaging systems with parallel data acquisition.
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Affiliation(s)
- Emma R. Hill
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
- Equal contribution
| | - Wenfeng Xia
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
- Equal contribution
| | - Matthew J. Clarkson
- Translational Imaging Group (TIG), Centre for Medical Image Computing (CMIC), Dept. of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
| | - Adrien E. Desjardins
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
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26
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Singh MKA, Parameshwarappa V, Hendriksen E, Steenbergen W, Manohar S. Photoacoustic-guided focused ultrasound for accurate visualization of brachytherapy seeds with the photoacoustic needle. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:120501. [PMID: 27924348 DOI: 10.1117/1.jbo.21.12.120501] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 11/14/2016] [Indexed: 05/20/2023]
Abstract
An important problem in minimally invasive photoacoustic (PA) imaging of brachytherapy seeds is reflection artifacts caused by the high signal from the optical fiber/needle tip reflecting off the seed. The presence of these artifacts confounds interpretation of images. In this letter, we demonstrate a recently developed concept called photoacoustic-guided focused ultrasound (PAFUSion) for the first time in the context of interstitial illumination PA imaging to identify and remove reflection artifacts. In this method, ultrasound (US) from the transducer is focused on the region of the optical fiber/needle tip identified in a first step using PA imaging. The image developed from the US diverging from the focus zone at the tip region visualizes only the reflections from seeds and other acoustic inhomogeneities, allowing identification of the reflection artifacts of the first step. These artifacts can then be removed from the PA image. Using PAFUSion, we demonstrate reduction of reflection artifacts and thereby improved interstitial PA visualization of brachytherapy seeds in phantom and <italic<ex vivo</italic< measurements on porcine tissue.
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Affiliation(s)
- Mithun Kuniyil Ajith Singh
- University of Twente, P.O. Box 217, Biomedical Photonic Imaging Group, Enschede 7500 AE, The Netherlands
| | - Vinay Parameshwarappa
- University of Twente, P.O. Box 217, Biomedical Photonic Imaging Group, Enschede 7500 AE, The Netherlands
| | - Ellen Hendriksen
- Department of Radiation Oncology, Medisch Spectrum Twente, P.O. Box 50000, Enschede 7512 KZ, The Netherlands
| | - Wiendelt Steenbergen
- University of Twente, P.O. Box 217, Biomedical Photonic Imaging Group, Enschede 7500 AE, The Netherlands
| | - Srirang Manohar
- University of Twente, P.O. Box 217, Biomedical Photonic Imaging Group, Enschede 7500 AE, The Netherlands
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27
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Singh MKA, Jaeger M, Frenz M, Steenbergen W. In vivo demonstration of reflection artifact reduction in photoacoustic imaging using synthetic aperture photoacoustic-guided focused ultrasound (PAFUSion). BIOMEDICAL OPTICS EXPRESS 2016; 7:2955-72. [PMID: 27570690 PMCID: PMC4986806 DOI: 10.1364/boe.7.002955] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 07/05/2016] [Accepted: 07/06/2016] [Indexed: 05/07/2023]
Abstract
Reflection artifacts caused by acoustic inhomogeneities are a critical problem in epi-mode biomedical photoacoustic imaging. High light fluence beneath the probe results in photoacoustic transients, which propagate into the tissue and reflect back from echogenic structures. These reflection artifacts cause problems in image interpretation and significantly impact the contrast and imaging depth. We recently proposed a method called PAFUSion (Photoacoustic-guided focused ultrasound) to identify such reflection artifacts in photoacoustic imaging. In its initial version, PAFUSion mimics the inward-travelling wavefield from small blood vessel-like PA sources by applying ultrasound pulses focused towards these sources, and thus provides a way to identify the resulting reflection artifacts. In this work, we demonstrate reduction of reflection artifacts in phantoms and in vivo measurements on human volunteers. In view of the spatially distributed PA sources that are found in clinical applications, we implemented an improved version of PAFUSion where photoacoustic signals are backpropagated to imitate the inward travelling wavefield and thus the reflection artifacts. The backpropagation is performed in a synthetic way based on the pulse-echo acquisitions after transmission on each single element of the transducer array. The results provide a direct confirmation that reflection artifacts are prominent in clinical epi-photoacoustic imaging, and that PAFUSion can strongly reduce these artifacts to improve deep-tissue photoacoustic imaging.
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Affiliation(s)
- Mithun Kuniyil Ajith Singh
- Biomedical Photonic Imaging Group, MIRA institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Michael Jaeger
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
| | - Martin Frenz
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
| | - Wiendelt Steenbergen
- Biomedical Photonic Imaging Group, MIRA institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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28
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Kang HJ, Bell MAL, Guo X, Boctor EM. Spatial Angular Compounding of Photoacoustic Images. IEEE TRANSACTIONS ON MEDICAL IMAGING 2016; 35:1845-55. [PMID: 26890642 PMCID: PMC5661032 DOI: 10.1109/tmi.2016.2531109] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Photoacoustic (PA) images utilize pulsed lasers and ultrasound transducers to visualize targets with higher optical absorption than the surrounding medium. However, they are susceptible to acoustic clutter and background noise artifacts that obfuscate biomedical structures of interest. We investigated three spatial-angular compounding methods to improve PA image quality for biomedical applications, implemented by combining multiple images acquired as an ultrasound probe was rotated about the elevational axis with the laser beam and target fixed. Compounding with conventional averaging was based on the pose information of each PA image, while compounding with weighted and selective averaging utilized both the pose and image content information. Weighted-average compounding enhanced PA images with the least distortion of signal size, particularly when there were large (i.e., 2.5 mm and 7 (°)) perturbations from the initial probe position. Selective-average compounding offered the best improvement in image quality with up 181, 1665, and 1568 times higher contrast, CNR, and SNR, respectively, compared to the mean values of individual PA images. The three presented spatial compounding methods have promising potential to enhance image quality in multiple photoacoustic applications.
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29
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O'Shea T, Bamber J, Fontanarosa D, van der Meer S, Verhaegen F, Harris E. Review of ultrasound image guidance in external beam radiotherapy part II: intra-fraction motion management and novel applications. Phys Med Biol 2016; 61:R90-137. [PMID: 27002558 DOI: 10.1088/0031-9155/61/8/r90] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Imaging has become an essential tool in modern radiotherapy (RT), being used to plan dose delivery prior to treatment and verify target position before and during treatment. Ultrasound (US) imaging is cost-effective in providing excellent contrast at high resolution for depicting soft tissue targets apart from those shielded by the lungs or cranium. As a result, it is increasingly used in RT setup verification for the measurement of inter-fraction motion, the subject of Part I of this review (Fontanarosa et al 2015 Phys. Med. Biol. 60 R77-114). The combination of rapid imaging and zero ionising radiation dose makes US highly suitable for estimating intra-fraction motion. The current paper (Part II of the review) covers this topic. The basic technology for US motion estimation, and its current clinical application to the prostate, is described here, along with recent developments in robust motion-estimation algorithms, and three dimensional (3D) imaging. Together, these are likely to drive an increase in the number of future clinical studies and the range of cancer sites in which US motion management is applied. Also reviewed are selections of existing and proposed novel applications of US imaging to RT. These are driven by exciting developments in structural, functional and molecular US imaging and analytical techniques such as backscatter tissue analysis, elastography, photoacoustography, contrast-specific imaging, dynamic contrast analysis, microvascular and super-resolution imaging, and targeted microbubbles. Such techniques show promise for predicting and measuring the outcome of RT, quantifying normal tissue toxicity, improving tumour definition and defining a biological target volume that describes radiation sensitive regions of the tumour. US offers easy, low cost and efficient integration of these techniques into the RT workflow. US contrast technology also has potential to be used actively to assist RT by manipulating the tumour cell environment and by improving the delivery of radiosensitising agents. Finally, US imaging offers various ways to measure dose in 3D. If technical problems can be overcome, these hold potential for wide-dissemination of cost-effective pre-treatment dose verification and in vivo dose monitoring methods. It is concluded that US imaging could eventually contribute to all aspects of the RT workflow.
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Affiliation(s)
- Tuathan O'Shea
- Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Sutton, London SM2 5NG, UK
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30
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Schwab HM, Beckmann MF, Schmitz G. Photoacoustic clutter reduction by inversion of a linear scatter model using plane wave ultrasound measurements. BIOMEDICAL OPTICS EXPRESS 2016; 7:1468-78. [PMID: 27446669 PMCID: PMC4929655 DOI: 10.1364/boe.7.001468] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 03/14/2016] [Accepted: 03/14/2016] [Indexed: 05/20/2023]
Abstract
Photoacoustic imaging aims to visualize light absorption properties of biological tissue by receiving a sound wave that is generated inside the observed object as a result of the photoacoustic effect. In clinical applications, the strong light absorption in human skin is a major problem. When high amplitude photoacoustic waves that originate from skin absorption propagate into the tissue, they are reflected back by acoustical scatterers and the reflections contribute to the received signal. The artifacts associated with these reflected waves are referred to as clutter or skin echo and limit the applicability of photoacoustic imaging for medical applications severely. This study seeks to exploit the acoustic tissue information gained by plane wave ultrasound measurements with a linear array in order to correct for reflections in the photoacoustic image. By deriving a theory for clutter waves in k-space and a matching inversion approach, photoacoustic measurements compensated for clutter are shown to be recovered.
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Affiliation(s)
| | | | - Georg Schmitz
- Medical Engineering, Ruhr-Universität Bochum, Bochum, 44780,
Germany
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Kuniyil Ajith Singh M, Steenbergen W. Photoacoustic-guided focused ultrasound (PAFUSion) for identifying reflection artifacts in photoacoustic imaging. PHOTOACOUSTICS 2015; 3:123-131. [PMID: 31467843 PMCID: PMC6713059 DOI: 10.1016/j.pacs.2015.09.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 08/22/2015] [Accepted: 09/23/2015] [Indexed: 05/04/2023]
Abstract
Influence of acoustic inhomogeneities and resulting reflection artifacts is an important problem in reflection-mode photoacoustic imaging. Absorption of light by skin and superficial optical absorbers will generate photoacoustic transients, which traverse into the tissue and get reflected from structures having different acoustic impedance. These reflected photoacoustic signals, when reconstructed, may appear in the region of interest, which causes difficulties in image interpretation. We propose a novel method to identify and potentially eliminate reflection artifacts in photoacoustic images using photoacoustic-guided focused ultrasound [PAFUSion]. Our method uses focused ultrasound pulses to mimic the wave field produced by photoacoustic sources and thus provides a way to identify reflection artifacts in clinical combined photoacoustic and pulse-echo ultrasound. Simulation and phantom results are presented to demonstrate the validity and impact of this method. Results show that PAFUSion can identify reflections in photoacoustic images and thus envisages potential for improving photoacoustic imaging of acoustically inhomogeneous tissue.
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Affiliation(s)
- Mithun Kuniyil Ajith Singh
- Biomedical Photonic Imaging Group, MIRA institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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Merčep E, Burton NC, Claussen J, Razansky D. Whole-body live mouse imaging by hybrid reflection-mode ultrasound and optoacoustic tomography. OPTICS LETTERS 2015; 40:4643-4646. [PMID: 26469584 DOI: 10.1364/ol.40.004643] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present a hybrid preclinical imaging scanner that optimally supports image acquisition in both reflection-mode ultrasonography and optoacoustic (OA) tomography modes. The system comprises a quasi-full-ring tomographic geometry capable of the simultaneous dual-mode imaging through entire cross sections of mice with in-plane spatial resolution in the range of 150 and 350 μm in the respective OA and ultrasound (US) imaging modes with an imaging speed of up to 10 two-dimensional frames per second. Three-dimensional whole-body data is subsequently rendered by rapid scanning of the imaged plane. The system further incorporates rapid laser wavelength tuning for real-time acquisition of multispectral OA data, which enables studies of longitudinal dynamics as well as fast kinetics and biodistribution of contrast agents. In vivo imaging performance is demonstrated by label-free hybrid anatomical scans through living mice, as well as real-time visualization of optical contrast agent perfusion. By setting new standards for whole-body tomographic imaging performance in both the OA and pulse-echo US modes, the developed hybrid imaging approach is expected to benefit numerous applications where the availability of high-quality structural information provided by the tomographic reflection-mode US can ease interpretation of the functional and molecular imaging results attained by the OA modality.
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Merčep E, Jeng G, Morscher S, Li PC, Razansky D. Hybrid optoacoustic tomography and pulse-echo ultrasonography using concave arrays. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2015; 62:1651-61. [PMID: 26415127 DOI: 10.1109/tuffc.2015.007058] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Implementation of hybrid imaging using optoacoustic tomography (OAT) and ultrasound (US) brings together the important advantages and complementary features of both methods. However, the fundamentally different physical contrast mechanisms of the two modalities may impose significant difficulties in the optimal tomographic data acquisition and image formation strategies. We investigate the applicability of the commonly applied imaging geometries for acquisition and reconstruction of hybrid optoacoustic tomography and pulse-echo ultrasound (OPUS) images. Optimization of the ultrasound image formation strategy using concave array geometry was implemented using a synthetic aperture method combined with spatial compounding. Experimental validation was performed using a custom-made multiplexer unit executing switching between the two modalities employing the same transducer array. A variety of array probes with different angular coverages were subsequently tested, including arrays for clinical hand-held imaging as well as stationary arrays for tomographic small animal imaging. The results demonstrate that acquisition of OAT data by mere addition of an illumination source to the common US linear array geometry may result in significant limited-view artifacts and overall loss of image quality. On the other hand, unsatisfactory US image quality is achieved with tomographic arrays solely optimized for OAT image acquisition without considering the optimal transmit-receive beamforming parameters. Optimal selection of the array pitch size, tomographic coverage and spatial compounding parameters has achieved here an accurate hybrid imaging performance, which was experimentally showcased in tissuemimicking phantoms, post-mortem mice, and hand-held imaging of a healthy volunteer. The efficient combination of the two modalities in a single imaging device reveals the true power of functional and molecular imaging capacities of OAT in addition to the morphological and functional imaging capabilities of US.
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Xia W, Nikitichev DI, Mari JM, West SJ, Pratt R, David AL, Ourselin S, Beard PC, Desjardins AE. Performance characteristics of an interventional multispectral photoacoustic imaging system for guiding minimally invasive procedures. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:86005. [PMID: 26263417 PMCID: PMC5217184 DOI: 10.1117/1.jbo.20.8.086005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 07/15/2015] [Indexed: 05/20/2023]
Abstract
Precise device guidance is important for interventional procedures in many different clinical fields including fetal medicine, regional anesthesia, interventional pain management, and interventional oncology. While ultrasound is widely used in clinical practice for real-time guidance, the image contrast that it provides can be insufficient for visualizing tissue structures such as blood vessels, nerves, and tumors. This study was centered on the development of a photoacoustic imaging system for interventional procedures that delivered excitation light in the ranges of 750 to 900 nm and 1150 to 1300 nm, with an optical fiber positioned in a needle cannula. Coregistered B-mode ultrasound images were obtained. The system, which was based on a commercial ultrasound imaging scanner, has an axial resolution in the vicinity of 100 μm and a submillimeter, depth-dependent lateral resolution. Using a tissue phantom and 800 nm excitation light, a simulated blood vessel could be visualized at a maximum distance of 15 mm from the needle tip. Spectroscopic contrast for hemoglobin and lipids was observed with ex vivo tissue samples, with photoacoustic signal maxima consistent with the respective optical absorption spectra. The potential for further optimization of the system is discussed.
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Affiliation(s)
- Wenfeng Xia
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
- Address all correspondence to: Wenfeng Xia,
| | - Daniil I. Nikitichev
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
| | - Jean Martial Mari
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
| | - Simeon J. West
- University College Hospital, Department of Anaesthesia, Main Theatres, Maple Bridge Link Corridor, Podium 3, 235 Euston Road, London NW1 2BU, United Kingdom
| | - Rosalind Pratt
- University College London, Institute for Women’s Health, 86-96 Chenies Mews, London WC1E 6HX, United Kingdom
| | - Anna L. David
- University College London, Institute for Women’s Health, 86-96 Chenies Mews, London WC1E 6HX, United Kingdom
| | - Sebastien Ourselin
- University College London, Center for Medical Imaging Computing, Gower Street, London WC1E 6BT, United Kingdom
| | - Paul C. Beard
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
| | - Adrien E. Desjardins
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
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Held G, Preisser S, Akarçay HG, Peeters S, Frenz M, Jaeger M. Effect of irradiation distance on image contrast in epi-optoacoustic imaging of human volunteers. BIOMEDICAL OPTICS EXPRESS 2014; 5:3765-80. [PMID: 25426309 PMCID: PMC4242016 DOI: 10.1364/boe.5.003765] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 09/06/2014] [Accepted: 09/25/2014] [Indexed: 05/20/2023]
Abstract
In combined clinical optoacoustic (OA) and ultrasound (US) imaging, epi-mode irradiation and detection integrated into one single probe offers flexible imaging of the human body. The imaging depth in epi-illumination is, however, strongly affected by clutter. As shown in previous phantom experiments, the location of irradiation plays an important role in clutter generation. We investigated the influence of the irradiation geometry on the local image contrast of clinical images, by varying the separation distance between the irradiated area and the acoustic imaging plane of a linear ultrasound transducer in an automated scanning setup. The results for different volunteers show that the image contrast can be enhanced on average by 25% and locally by more than a factor of two, when the irradiated area is slightly separated from the probe. Our findings have an important impact on the design of future optoacoustic probes for clinical application.
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Affiliation(s)
- Gerrit Held
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012 Bern,
Switzerland
| | - Stefan Preisser
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012 Bern,
Switzerland
| | - H. Günhan Akarçay
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012 Bern,
Switzerland
| | - Sara Peeters
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012 Bern,
Switzerland
| | - Martin Frenz
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012 Bern,
Switzerland
| | - Michael Jaeger
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012 Bern,
Switzerland
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