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Sun L, Gonzalez G, Pandey PK, Wang S, Kim K, Limoli C, Chen Y, Xiang L. Towards quantitative in vivo dosimetry using x-ray acoustic computed tomography. Med Phys 2023; 50:6894-6907. [PMID: 37203253 PMCID: PMC10656364 DOI: 10.1002/mp.16476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 04/05/2023] [Accepted: 04/30/2023] [Indexed: 05/20/2023] Open
Abstract
BACKGROUND Radiation dosimetry is essential for radiation therapy (RT) to ensure that radiation dose is accurately delivered to the tumor. Despite its wide use in clinical intervention, the delivered radiation dose can only be planned and verified via simulation. This makes precision radiotherapy challenging while in-line verification of the delivered dose is still absent in the clinic. X-ray-induced acoustic computed tomography (XACT) has recently been proposed as an imaging tool for in vivo dosimetry. PURPOSE Most of the XACT studies focus on localizing the radiation beam. However, it has not been studied for its potential for quantitative dosimetry. The aim of this study was to investigate the feasibility of using XACT for quantitative in vivo dose reconstruction during radiotherapy. METHODS Varian Eclipse system was used to generate simulated uniform and wedged 3D radiation field with a size of 4 cm× $ \times \ $ 4 cm. In order to use XACT for quantitative dosimetry measurements, we have deconvoluted the effects of both the x-ray pulse shape and the finite frequency response of the ultrasound detector. We developed a model-based image reconstruction algorithm to quantify radiation dose in vivo using XACT imaging, and universal back-projection (UBP) reconstruction is used as comparison. The reconstructed dose was calibrated before comparing it to the percent depth dose (PDD) profile. Structural similarity index matrix (SSIM) and root mean squared error (RMSE) are used for numeric evaluation. Experimental signals were acquired from 4 cm× $ \times \ $ 4 cm radiation field created by Linear Accelerator (LINAC) at depths of 6, 8, and 10 cm beneath the water surface. The acquired signals were processed before reconstruction to achieve accurate results. RESULTS Applying model-based reconstruction algorithm with non-negative constraints successfully reconstructed accurate radiation dose in 3D simulation study. The reconstructed dose matches well with the PDD profile after calibration in experiments. The SSIMs between the model-based reconstructions and initial doses are over 85%, and the RMSEs of model-based reconstructions are eight times lower than the UBP reconstructions. We have also shown that XACT images can be displayed as pseudo-color maps of acoustic intensity, which correspond to different radiation doses in the clinic. CONCLUSION Our results show that the XACT imaging by model-based reconstruction algorithm is considerably more accurate than the dose reconstructed by UBP algorithm. With proper calibration, XACT is potentially applicable to the clinic for quantitative in vivo dosimetry across a wide range of radiation modalities. In addition, XACT's capability of real-time, volumetric dose imaging seems well-suited for the emerging field of ultrahigh dose rate "FLASH" radiotherapy.
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Affiliation(s)
- Leshan Sun
- Department of Biomedical Engineering, University of California, Irvine, California, USA
| | - Gilberto Gonzalez
- Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Prabodh Kumar Pandey
- Department of Radiological Sciences, University of California at Irvine, Irvine, California, USA
| | - Siqi Wang
- Department of Biomedical Engineering, University of California, Irvine, California, USA
| | - Kaitlyn Kim
- Department of Biomedical Engineering, University of California, Irvine, California, USA
| | - Charles Limoli
- Department of Radiation Oncology, University of California Irvine, Medical Sciences I, Irvine, California, USA
| | - Yong Chen
- Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Liangzhong Xiang
- Department of Biomedical Engineering, University of California, Irvine, California, USA
- Department of Radiological Sciences, University of California at Irvine, Irvine, California, USA
- Beckman Laser Institute, University of California at Irvine, Irvine, California, USA
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Ozbek A, Dean-Ben XL, Razansky D. Universal Real-Time Adaptive Signal Compression for High-Frame-Rate Optoacoustic Tomography. IEEE TRANSACTIONS ON MEDICAL IMAGING 2022; 41:2903-2911. [PMID: 35588420 DOI: 10.1109/tmi.2022.3175471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Optoacoustic tomography (OAT) has recently been advanced toward ultrafast volumetric imaging frame rates in the kilohertz range. As a result, excessive data processing and storage capacity requirements are increasingly being imposed on the imaging systems. OAT data commonly exhibit significant sparsity across the spatial, temporal or spectral domains, which facilitated the development of compressed sensing algorithms exploiting various sparse acquisition and under-sampling schemes to reduce data rates. However, performance of compressed sensing critically depends on a priori knowledge on the type of acquired data and/or imaged object, commonly resulting in lack of general applicability and unpredictable image quality. In this work, we report on a fast adaptive OAT data compression framework operating on fully sampled tomographic data. It is based on a wavelet packet transform that maximizes the data compression ratio according to the desired signal energy loss. A dedicated reconstruction method was further developed that efficiently renders images directly from the compressed data. Up to 1000x compression ratios were achieved while providing efficient control over the resulting image quality from arbitrary datasets exhibiting diverse spatial, temporal and spectral characteristics. Our approach enables faster and longer acquisitions and facilitates long-term storage of large OAT datasets.
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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
- Address all correspondence to William C. Vogt,
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Qi L, Wu J, Li X, Zhang S, Huang S, Feng Q, Chen W. Photoacoustic Tomography Image Restoration With Measured Spatially Variant Point Spread Functions. IEEE TRANSACTIONS ON MEDICAL IMAGING 2021; 40:2318-2328. [PMID: 33939607 DOI: 10.1109/tmi.2021.3077022] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The spatial resolution of photoacoustic tomography (PAT) can be characterized by the point spread function (PSF) of the imaging system. Due to the tomographic detection geometry, the PAT image degradation model could be generally described by using spatially variant PSFs. Deconvolution of the PAT image with these PSFs could restore image resolution and recover object details. Previous PAT image restoration algorithms assume that the degraded images can be restored by either a single uniform PSF, or some blind estimation of the spatially variant PSFs. In this work, we propose a PAT image restoration method to improve image quality and resolution based on experimentally measured spatially variant PSFs. Using photoacoustic absorbing microspheres, we design a rigorous PSF measurement procedure, and successfully acquire a dense set of spatially variant PSFs for a commercial cross-sectional PAT system. A pixel-wise PSF map is further obtained by employing a multi-Gaussian-based fitting and interpolation algorithm. To perform image restoration, an optimization-based iterative restoration model with two kinds of regularizations is proposed. We perform phantom and in vivo mice imaging experiments to verify the proposed method, and the results show significant image quality and resolution improvement.
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Deán-Ben XL, Razansky D. Optoacoustic imaging of the skin. Exp Dermatol 2021; 30:1598-1609. [PMID: 33987867 DOI: 10.1111/exd.14386] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 04/23/2021] [Accepted: 04/29/2021] [Indexed: 12/11/2022]
Abstract
Optoacoustic (OA, photoacoustic) imaging capitalizes on the synergistic combination of light excitation and ultrasound detection to empower biological and clinical investigations with rich optical contrast while effectively bridging the gap between micro and macroscopic imaging realms. State-of-the-art OA embodiments consistently provide images at micron-scale resolution through superficial tissue layers by means of focused illumination that can be smoothly exchanged for acoustic-resolution images at diffuse light depths of several millimetres to centimetres via ultrasound beamforming or tomographic reconstruction. Taken together, this unique multi-scale imaging capacity opens unprecedented capabilities for high-resolution in vivo interrogations of the skin at scalable depths. Moreover, diverse anatomical and functional information is retrieved via dynamic mapping of endogenous chromophores such as haemoglobin, melanin, lipids, collagen, water and others. This, along with the use of non-ionizing radiation, facilitates a clinical translation of the OA modalities. We review recent progress in OA imaging of the skin in preclinical and clinical studies exploiting the rich contrast provided by endogenous substances in tissues. The imaging capabilities of existing approaches are discussed in the context of initial translational studies on skin cancer, inflammatory skin diseases, wounds and other conditions.
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Affiliation(s)
- Xosé Luís Deán-Ben
- Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Zurich, Switzerland.,Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Zurich, Switzerland
| | - Daniel Razansky
- Institute of Pharmacology and Toxicology, Faculty of Medicine, University of Zurich, Zurich, Switzerland.,Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Zurich, Switzerland
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Zhou HC, Ren J, Lin Y, Gao D, Hu D, Yin T, Qiu C, Miao X, Liu C, Liu X, Zheng H, Zheng R, Sheng Z. Intravital NIR-II three-dimensional photoacoustic imaging of biomineralized copper sulfide nanoprobes. J Mater Chem B 2021; 9:3005-3014. [PMID: 33704309 DOI: 10.1039/d0tb03010d] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photoacoustic (PA) imaging with functional nanoprobes in the second near-infrared region (NIR-II, 1000-1700 nm) has aroused much interest due to its deep tissue penetration and high maximum laser permissible exposure. However, most NIR-II PA imaging is performed using the two-dimensional (2D) imaging modality, which impedes the comprehension of the in vivo biodistribution, angiography and molecular-targeted performance of NIR-II nanoprobes (NPs). Herein, we report the systematic monitoring of biomineralized copper sulfide (CuS) NPs, typical NIR-II NPs, in mouse models by employing NIR-II three-dimensional (3D) PA imaging. The advanced imaging modality provides dynamic information about the 3D biodistribution and metabolic pathway of CuS NPs. We also achieved contrast-enhanced 3D PA imaging of abdominal and cerebral vessels at a high signal-to-background ratio. Moreover, the tumor-targeted CuS NPs conjugated with the bombesin peptide endowed NIR-II 3D PA with superior performance in imaging orthotopic tumors both deep in the prostate and in the brain beneath the intact scalp and skull. Our results highlight the potential of NIR-II 3D PA imaging for the evaluation of the in vivo behavior of NPs, thus providing a promising strategy for screening NPs in clinical translational studies.
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Affiliation(s)
- Hui-Chao Zhou
- Department of Ultrasound, Laboratory of Novel Optoacoustic/Ultrasonic imaging, Guangdong Key Laboratory of Liver Disease Research, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510630, P. R. China.
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Qi L, Huang S, Li X, Zhang S, Lu L, Feng Q, Chen W. Cross-sectional photoacoustic tomography image reconstruction with a multi-curve integration model. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2020; 197:105731. [PMID: 32947070 DOI: 10.1016/j.cmpb.2020.105731] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 08/29/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND AND OBJECTIVE In acoustic inversion of photoacoustic tomography (PAT), an imaging model that precisely describes both the ultrasonic wave propagation and the detector properties is of crucial importance. Inspired by the multi-stripe integration model in clinical X-ray computed tomography systems, in this work, we introduce the Multi-Curve-Integration-based acoustic inversion for cross-sectional Photoacoustic Tomography (MCI-PAT). METHODS We assumed that in cross-sectional PAT system, the three-dimensional (3-D) wave propagation problem could be reduced to a two-dimensional (2-D) problem in a limited, yet sufficient field of view. Under such condition, the MCI-PAT imaging model is generated by integrating several circular acoustic curves, the centers of which are points evenly distributed on the finite-size ultrasonic transducer surface. In this way, the spatial detector response is taken into account, while its computational burden does not largely increase because the integration process is performed only on a 2-D plane. RESULTS As proven by simulation, phantom and in vivo small animal experiments, the MCI-PAT method leads to promising improvement in PAT image quality. Comparing to traditional imaging models that considered only a single acoustic curve, our proposed method successfully improved the visibility of small structures and achieved evident enhancement on signal-to-noise ratio. CONCLUSIONS The performance of the MCI-PAT method demonstrates that for cross-sectional PAT, a 2-D simplification of the propagation of multiple photoacoustic waves is feasible. Due to its simplicity, our method can be used as an add-on to current system models considering only a single acoustic curve.
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Affiliation(s)
- Li Qi
- Guangdong Provincial Key Laboratory of Medical Image Processing and School of Biomedical Engineering, Southern Medical University, 1023 Shatai Rd., Baiyun District, Guangzhou 510900, Guangdong, China.
| | - Shixian Huang
- Guangdong Provincial Key Laboratory of Medical Image Processing and School of Biomedical Engineering, Southern Medical University, 1023 Shatai Rd., Baiyun District, Guangzhou 510900, Guangdong, China
| | - Xipan Li
- Guangdong Provincial Key Laboratory of Medical Image Processing and School of Biomedical Engineering, Southern Medical University, 1023 Shatai Rd., Baiyun District, Guangzhou 510900, Guangdong, China
| | - Shuangyang Zhang
- Guangdong Provincial Key Laboratory of Medical Image Processing and School of Biomedical Engineering, Southern Medical University, 1023 Shatai Rd., Baiyun District, Guangzhou 510900, Guangdong, China
| | - Lijun Lu
- Guangdong Provincial Key Laboratory of Medical Image Processing and School of Biomedical Engineering, Southern Medical University, 1023 Shatai Rd., Baiyun District, Guangzhou 510900, Guangdong, China
| | - Qianjin Feng
- Guangdong Provincial Key Laboratory of Medical Image Processing and School of Biomedical Engineering, Southern Medical University, 1023 Shatai Rd., Baiyun District, Guangzhou 510900, Guangdong, China
| | - Wufan Chen
- Guangdong Provincial Key Laboratory of Medical Image Processing and School of Biomedical Engineering, Southern Medical University, 1023 Shatai Rd., Baiyun District, Guangzhou 510900, Guangdong, China.
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Deán-Ben XL, López-Schier H, Razansky D. Optoacoustic micro-tomography at 100 volumes per second. Sci Rep 2017; 7:6850. [PMID: 28761048 PMCID: PMC5537301 DOI: 10.1038/s41598-017-06554-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 06/14/2017] [Indexed: 01/06/2023] Open
Abstract
Optical microscopy remains a fundamental tool for modern biological discovery owing to its excellent spatial resolution and versatile contrast in visualizing cellular and sub-cellular structures. Yet, the time domain is paramount for the observation of biological dynamics in living systems. Commonly, acquisition of microscopy data involves scanning of a spherically- or cylindrically-focused light beam across the imaged volume, which significantly limits temporal resolution in 3D. Additional complications arise from intense light scattering of biological tissues, further restraining the effective penetration depth and field of view of optical microscopy techniques. To overcome these limitations, we devised a fast optoacoustic micro-tomography (OMT) approach based on simultaneous acquisition of 3D image data with a high-density hemispherical ultrasound array having effective detection bandwidth beyond 25 MHz. We demonstrate fast three-dimensional imaging of freely-swimming zebrafish larvae, achieving 3D imaging speed of 100 volumes per second with isotropic spatial resolution approaching the dimensions of large cells across a field of view exceeding 50mm3. As opposed to other microscopy techniques based on optical contrast, OMT resolves optical absorption acoustically using unfocused light excitation. Thus, no penetration barriers are imposed by light scattering in deep tissues, suggesting it as a powerful approach for multi-scale functional and molecular imaging applications.
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Affiliation(s)
- X Luís Deán-Ben
- Institute of Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany
| | - Hernán López-Schier
- Research Unit Sensory Biology and Organogenesis, Helmholtz Center Munich, Neuherberg, Germany
| | - Daniel Razansky
- Institute of Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg, Germany.
- School of Medicine and School of Bioengineering, Technical University of Munich, München, Germany.
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Deán-Ben XL, Gottschalk S, Mc Larney B, Shoham S, Razansky D. Advanced optoacoustic methods for multiscale imaging of in vivo dynamics. Chem Soc Rev 2017; 46:2158-2198. [PMID: 28276544 PMCID: PMC5460636 DOI: 10.1039/c6cs00765a] [Citation(s) in RCA: 182] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Visualization of dynamic functional and molecular events in an unperturbed in vivo environment is essential for understanding the complex biology of living organisms and of disease state and progression. To this end, optoacoustic (photoacoustic) sensing and imaging have demonstrated the exclusive capacity to maintain excellent optical contrast and high resolution in deep-tissue observations, far beyond the penetration limits of modern microscopy. Yet, the time domain is paramount for the observation and study of complex biological interactions that may be invisible in single snapshots of living systems. This review focuses on the recent advances in optoacoustic imaging assisted by smart molecular labeling and dynamic contrast enhancement approaches that enable new types of multiscale dynamic observations not attainable with other bio-imaging modalities. A wealth of investigated new research topics and clinical applications is further discussed, including imaging of large-scale brain activity patterns, volumetric visualization of moving organs and contrast agent kinetics, molecular imaging using targeted and genetically expressed labels, as well as three-dimensional handheld diagnostics of human subjects.
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Affiliation(s)
- X L Deán-Ben
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
| | - S Gottschalk
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
| | - B Mc Larney
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany. and Faculty of Medicine, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany
| | - S Shoham
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, 32000 Haifa, Israel
| | - D Razansky
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany. and Faculty of Medicine, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany
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Deán-Ben XL, Fehm TF, Ford SJ, Gottschalk S, Razansky D. Spiral volumetric optoacoustic tomography visualizes multi-scale dynamics in mice. LIGHT, SCIENCE & APPLICATIONS 2017; 6:e16247. [PMID: 30167242 PMCID: PMC6062167 DOI: 10.1038/lsa.2016.247] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 10/20/2016] [Accepted: 10/28/2016] [Indexed: 05/04/2023]
Abstract
Imaging dynamics at different temporal and spatial scales is essential for understanding the biological complexity of living organisms, disease state and progression. Optoacoustic imaging has been shown to offer exclusive applicability across multiple scales with excellent optical contrast and high resolution in deep-tissue observations. Yet, efficient visualization of multi-scale dynamics remained difficult with state-of-the-art systems due to inefficient trade-offs between image acquisition time and effective field of view. Herein, we introduce the spiral volumetric optoacoustic tomography technique that provides spectrally enriched high-resolution contrast across multiple spatiotemporal scales. In vivo experiments in mice demonstrate a wide range of dynamic imaging capabilities, from three-dimensional high-frame-rate visualization of moving organs and contrast agent kinetics in selected areas to whole-body longitudinal studies with unprecedented image quality. The newly introduced paradigm shift in imaging of multi-scale dynamics adds to the multifarious advantages provided by the optoacoustic technology for structural, functional and molecular imaging.
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Affiliation(s)
- X Luís Deán-Ben
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, 85764 Neuherberg, Germany
| | - Thomas F Fehm
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, 85764 Neuherberg, Germany
- School of Medicine and School of Bioengineering, Technical University of Munich, 81675 Munich, Germany
| | - Steven J Ford
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, 85764 Neuherberg, Germany
| | - Sven Gottschalk
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, 85764 Neuherberg, Germany
| | - Daniel Razansky
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, 85764 Neuherberg, Germany
- School of Medicine and School of Bioengineering, Technical University of Munich, 81675 Munich, Germany
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Deán-Ben XL, Razansky D. On the link between the speckle free nature of optoacoustics and visibility of structures in limited-view tomography. PHOTOACOUSTICS 2016; 4:133-140. [PMID: 28066714 PMCID: PMC5200938 DOI: 10.1016/j.pacs.2016.10.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 09/30/2016] [Accepted: 10/13/2016] [Indexed: 05/08/2023]
Abstract
Similar to pulse-echo ultrasound, optoacoustic imaging encodes the location of optical absorbers by the time-of-flight of ultrasound waves. Yet, signal generation mechanisms are fundamentally different for the two modalities, leading to significant distinction between the optimum image formation strategies. While interference of back-scattered ultrasound waves with random phases causes speckle noise in ultrasound images, speckle formation is hindered by the strong correlation between the optoacoustic responses corresponding to individual sources. However, visibility of structures is severely hampered when attempting to acquire optoacoustic images under limited-view tomographic geometries. In this tutorial article, we systematically describe the basic principles of optoacoustic signal generation and image formation for objects ranging from individual sub-resolution absorbers to a continuous absorption distribution. The results are of relevance for the proper interpretation of optoacoustic images acquired under limited-view scenarios and may also serve as a basis for optimal design of tomographic acquisition geometries and image formation strategies.
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He H, Mandal S, Buehler A, Deán-Ben XL, Razansky D, Ntziachristos V. Improving Optoacoustic Image Quality via Geometric Pixel Super-Resolution Approach. IEEE TRANSACTIONS ON MEDICAL IMAGING 2016; 35:812-8. [PMID: 26552079 DOI: 10.1109/tmi.2015.2497159] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
High fidelity optoacoustic (photoacoustic) tomography requires dense spatial sampling of optoacoustic signals using point acoustic detectors. However, in practice, spatial resolution of the images is often limited by limited sampling either due to coarse multi-element arrays or time in raster scan measurements. Herein, we investigate a method that integrates information from multiple optoacoustic images acquired at sub-diffraction steps into one high resolution image by means of an iterative registration algorithm. Experimental validations performed in target phantoms and ex vivo tissue samples confirm that the suggested approach renders significant improvements in terms of optoacoustic image resolution and quality without introducing significant alterations into the signal acquisition hardware or inversion algorithms.
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Simultaneous visualization of tumour oxygenation, neovascularization and contrast agent perfusion by real-time three-dimensional optoacoustic tomography. Eur Radiol 2015; 26:1843-51. [DOI: 10.1007/s00330-015-3980-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 07/20/2015] [Accepted: 08/10/2015] [Indexed: 01/18/2023]
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Han Y, Tzoumas S, Nunes A, Ntziachristos V, Rosenthal A. Sparsity-based acoustic inversion in cross-sectional multiscale optoacoustic imaging. Med Phys 2015; 42:5444-52. [DOI: 10.1118/1.4928596] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Deán-Ben XL, Ford SJ, Razansky D. High-frame rate four dimensional optoacoustic tomography enables visualization of cardiovascular dynamics and mouse heart perfusion. Sci Rep 2015; 5:10133. [PMID: 26130401 PMCID: PMC4486932 DOI: 10.1038/srep10133] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 03/31/2015] [Indexed: 12/17/2022] Open
Abstract
Functional imaging of mouse models of cardiac health and disease provides a major contribution to our fundamental understanding of the mammalian heart. However, imaging murine hearts presents significant challenges due to their small size and rapid heart rate. Here we demonstrate the feasibility of high-frame-rate, noninvasive optoacoustic imaging of the murine heart. The temporal resolution of 50 three-dimensional frames per second provides functional information at important phases of the cardiac cycle without the use of gating or other motion-reduction methods. Differentiation of the blood oxygenation state in the heart chambers was enabled by exploiting the wavelength dependence of optoacoustic signals. Real-time volumetric tracking of blood perfusion in the cardiac chambers was also evaluated using indocyanine green. Taken together, the newly-discovered capacities offer a unique tool set for in-vivo structural and functional imaging of the whole heart with high spatio-temporal resolution in all three dimensions.
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Affiliation(s)
- Xosé Luís Deán-Ben
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstädter Landstraβe 1, 85764 Neuherberg, Germany
| | - Steven James Ford
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstädter Landstraβe 1, 85764 Neuherberg, Germany
| | - Daniel Razansky
- 1] Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstädter Landstraβe 1, 85764 Neuherberg, Germany [2] Faculty of Medicine, Technical University of Munich, Ismaninger Straβe 22, 81675 Munich, Germany
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Lutzweiler C, Deán-Ben XL, Razansky D. Expediting model-based optoacoustic reconstructions with tomographic symmetries. Med Phys 2014; 41:013302. [PMID: 24387532 DOI: 10.1118/1.4846055] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Image quantification in optoacoustic tomography implies the use of accurate forward models of excitation, propagation, and detection of optoacoustic signals while inversions with high spatial resolution usually involve very large matrices, leading to unreasonably long computation times. The development of fast and memory efficient model-based approaches represents then an important challenge to advance on the quantitative and dynamic imaging capabilities of tomographic optoacoustic imaging. METHODS Herein, a method for simplification and acceleration of model-based inversions, relying on inherent symmetries present in common tomographic acquisition geometries, has been introduced. The method is showcased for the case of cylindrical symmetries by using polar image discretization of the time-domain optoacoustic forward model combined with efficient storage and inversion strategies. RESULTS The suggested methodology is shown to render fast and accurate model-based inversions in both numerical simulations and post mortem small animal experiments. In case of a full-view detection scheme, the memory requirements are reduced by one order of magnitude while high-resolution reconstructions are achieved at video rate. CONCLUSIONS By considering the rotational symmetry present in many tomographic optoacoustic imaging systems, the proposed methodology allows exploiting the advantages of model-based algorithms with feasible computational requirements and fast reconstruction times, so that its convenience and general applicability in optoacoustic imaging systems with tomographic symmetries is anticipated.
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Affiliation(s)
- Christian Lutzweiler
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstädter Landstraβe 1, 85764 Neuherberg, Germany and Faculty of Medicine, Technical University of Munich, Ismaninger Straβe 22, 81675 Munich, Germany
| | - Xosé Luís Deán-Ben
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstädter Landstraβe 1, 85764 Neuherberg, Germany and Faculty of Medicine, Technical University of Munich, Ismaninger Straβe 22, 81675 Munich, Germany
| | - Daniel Razansky
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstädter Landstraβe 1, 85764 Neuherberg, Germany and Faculty of Medicine, Technical University of Munich, Ismaninger Straβe 22, 81675 Munich, Germany
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