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Zhao Y, Li S, Zhang L, Tang Z, Wei D, Zhang H, Xie Q, Yi H, He X. Two-step reconstruction framework of fluorescence molecular tomography based on energy statistical probability. JOURNAL OF BIOPHOTONICS 2024; 17:e202300480. [PMID: 38351740 DOI: 10.1002/jbio.202300480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/17/2024] [Accepted: 01/28/2024] [Indexed: 05/04/2024]
Abstract
Fluorescence molecular tomography (FMT), as a promising technique for early tumor detection, can non-invasively visualize the distribution of fluorescent marker probe three-dimensionally. However, FMT reconstruction is a severely ill-posed problem, which remains an obstacle to wider application of FMT. In this paper, a two-step reconstruction framework was proposed for FMT based on the energy statistical probability. First, the tissue structural information obtained from computed tomography (CT) is employed to associate the tissue optical parameters for rough solution in the global region. Then, according to the global-region reconstruction results, the probability that the target belongs to each region can be calculated. The region with the highest probability is delineated as region of interest to realize accurate and fast source reconstruction. Numerical simulations and in vivo experiments were carried out to evaluate the effectiveness of the proposed framework. The encouraging results demonstrate the significant effectiveness and potential of our method for practical FMT applications.
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Affiliation(s)
- Yizhe Zhao
- The Xi'an Key Laboratory of Radiomics and Intelligent Perception, Xi'an, China
- School of Information Sciences and Technology, Northwest University, Xi'an, China
| | - Shuangchen Li
- The Xi'an Key Laboratory of Radiomics and Intelligent Perception, Xi'an, China
- School of Information Sciences and Technology, Northwest University, Xi'an, China
| | - Lizhi Zhang
- The Xi'an Key Laboratory of Radiomics and Intelligent Perception, Xi'an, China
- School of Information Sciences and Technology, Northwest University, Xi'an, China
| | - Zijian Tang
- The Xi'an Key Laboratory of Radiomics and Intelligent Perception, Xi'an, China
- School of Information Sciences and Technology, Northwest University, Xi'an, China
| | - De Wei
- The Xi'an Key Laboratory of Radiomics and Intelligent Perception, Xi'an, China
- School of Information Sciences and Technology, Northwest University, Xi'an, China
| | - Heng Zhang
- The Xi'an Key Laboratory of Radiomics and Intelligent Perception, Xi'an, China
- School of Information Sciences and Technology, Northwest University, Xi'an, China
| | - Qiong Xie
- The First Hospital of Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Huangjian Yi
- The Xi'an Key Laboratory of Radiomics and Intelligent Perception, Xi'an, China
- School of Information Sciences and Technology, Northwest University, Xi'an, China
| | - Xiaowei He
- The Xi'an Key Laboratory of Radiomics and Intelligent Perception, Xi'an, China
- School of Information Sciences and Technology, Northwest University, Xi'an, China
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2
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Vega JD, Hara D, Schmidt RM, Abuhaija MB, Tao W, Dogan N, Pollack A, Ford JC, Shi J. In vivo active-targeting fluorescence molecular imaging with adaptive background fluorescence subtraction. Front Oncol 2023; 13:1130155. [PMID: 36998445 PMCID: PMC10043309 DOI: 10.3389/fonc.2023.1130155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 02/28/2023] [Indexed: 03/18/2023] Open
Abstract
Using active tumor-targeting nanoparticles, fluorescence imaging can provide highly sensitive and specific tumor detection, and precisely guide radiation in translational radiotherapy study. However, the inevitable presence of non-specific nanoparticle uptake throughout the body can result in high levels of heterogeneous background fluorescence, which limits the detection sensitivity of fluorescence imaging and further complicates the early detection of small cancers. In this study, background fluorescence emanating from the baseline fluorophores was estimated from the distribution of excitation light transmitting through tissues, by using linear mean square error estimation. An adaptive masked-based background subtraction strategy was then implemented to selectively refine the background fluorescence subtraction. First, an in vivo experiment was performed on a mouse intratumorally injected with passively targeted fluorescent nanoparticles, to validate the reliability and robustness of the proposed method in a stringent situation wherein the target fluorescence was overlapped with the strong background. Then, we conducted in vivo studies on 10 mice which were inoculated with orthotopic breast tumors and intravenously injected with actively targeted fluorescent nanoparticles. Results demonstrated that active targeting combined with the proposed background subtraction method synergistically increased the accuracy of fluorescence molecular imaging, affording sensitive tumor detection.
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Affiliation(s)
- Jorge D. Vega
- Department of Radiation Oncology, Miller School of Medicine, University of Miami, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, United States
| | - Daiki Hara
- Department of Radiation Oncology, Miller School of Medicine, University of Miami, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, United States
| | - Ryder M. Schmidt
- Department of Radiation Oncology, Miller School of Medicine, University of Miami, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, United States
| | - Marwan B. Abuhaija
- Department of Radiation Oncology, Miller School of Medicine, University of Miami, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, United States
| | - Wensi Tao
- Department of Radiation Oncology, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Nesrin Dogan
- Department of Radiation Oncology, Miller School of Medicine, University of Miami, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, United States
| | - Alan Pollack
- Department of Radiation Oncology, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - John C. Ford
- Department of Radiation Oncology, Miller School of Medicine, University of Miami, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, United States
- *Correspondence: John C. Ford, ; Junwei Shi,
| | - Junwei Shi
- Department of Radiation Oncology, Miller School of Medicine, University of Miami, Miami, FL, United States
- *Correspondence: John C. Ford, ; Junwei Shi,
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3
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Nizam NI, Ochoa M, Smith JT, Intes X. Deep learning-based fusion of widefield diffuse optical tomography and micro-CT structural priors for accurate 3D reconstructions. BIOMEDICAL OPTICS EXPRESS 2023; 14:1041-1053. [PMID: 36950248 PMCID: PMC10026582 DOI: 10.1364/boe.480091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 01/10/2023] [Accepted: 01/24/2023] [Indexed: 06/17/2023]
Abstract
Widefield illumination and detection strategies leveraging structured light have enabled fast and robust probing of tissue properties over large surface areas and volumes. However, when applied to diffuse optical tomography (DOT) applications, they still require a time-consuming and expert-centric solving of an ill-posed inverse problem. Deep learning (DL) models have been recently proposed to facilitate this challenging step. Herein, we expand on a previously reported deep neural network (DNN) -based architecture (modified AUTOMAP - ModAM) for accurate and fast reconstructions of the absorption coefficient in 3D DOT based on a structured light illumination and detection scheme. Furthermore, we evaluate the improved performances when incorporating a micro-CT structural prior in the DNN-based workflow, named Z-AUTOMAP. This Z-AUTOMAP significantly improves the widefield imaging process's spatial resolution, especially in the transverse direction. The reported DL-based strategies are validated both in silico and in experimental phantom studies using spectral micro-CT priors. Overall, this is the first successful demonstration of micro-CT and DOT fusion using deep learning, greatly enhancing the prospect of rapid data-integration strategies, often demanded in challenging pre-clinical scenarios.
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Nouizi F, Erkol H, Nikkhah D, Kwong TC, Gulsen G. Development of a preclinical CCD-based temperature modulated fluorescence tomography platform. BIOMEDICAL OPTICS EXPRESS 2022; 13:5740-5752. [PMID: 36733748 PMCID: PMC9872903 DOI: 10.1364/boe.470723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 09/25/2022] [Accepted: 09/26/2022] [Indexed: 05/11/2023]
Abstract
In preclinical research, fluorescence molecular tomography (FMT) is the most sensitive imaging modality to interrogate whole-body and provide 3D distribution of fluorescent contract agents. Despite its superior sensitivity, its mediocre spatial-resolution has been the main barrier to its clinical translation. This limitation is mainly due to the high scattering of optical photons in biological tissue together with the limited boundary measurements that lead to an undetermined and ill-posed inverse problem. To overcome the limitations of FMT, we previously introduced a novel method termed, Temperature Modulated Fluorescence Tomography (TMFT). TMFT utilizes thermos-sensitive fluorescent agents (ThermoDots) as a key component and localizes them with high-intensity focused ultrasound (HIFU). Scanning the focused HIFU beam having a diameter Ø = 1.3 mm across the tissue while monitoring the variation in the measured fluorescence signals reveals the position of the ThermoDots with high spatial accuracy. We have formerly built a prototype TMFT system that uses optical fibers for detection. In this paper, we present an upgraded version using a CCD camera-based detection that enables non-contact imaging. In this version, the animal under investigation is placed on an ultrasound transparent membrane, which eliminates the need for its immersion in optical matching fluids that were required by the fiber-based system. This CCD-based system will pave the way for convenient and wide-spread use of TMFT in preclinical research. Its performance validation on phantom studies demonstrates that high spatial-resolution (∼1.3 mm) and quantitative accuracy in recovered fluorophore concentration (<3% error) can be achieved.
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Affiliation(s)
- Farouk Nouizi
- Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California Irvine, CA 92697, USA
- Chao Family Comprehensive Cancer Center, University of California Irvine, CA 92697, USA
| | - Hakan Erkol
- Department of Physics, Bogazici University, Bebek, 34342, Istanbul, Turkey
| | - Deniz Nikkhah
- Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California Irvine, CA 92697, USA
| | - Tiffany C. Kwong
- Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California Irvine, CA 92697, USA
| | - Gultekin Gulsen
- Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California Irvine, CA 92697, USA
- Chao Family Comprehensive Cancer Center, University of California Irvine, CA 92697, USA
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Zhang X, Cao X, Zhang P, Song F, Zhang J, Zhang L, Zhang G. Self-Training Strategy Based on Finite Element Method for Adaptive Bioluminescence Tomography Reconstruction. IEEE TRANSACTIONS ON MEDICAL IMAGING 2022; 41:2629-2643. [PMID: 35436185 DOI: 10.1109/tmi.2022.3167809] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Bioluminescence tomography (BLT) is a promising pre-clinical imaging technique for a wide variety of biomedical applications, which can non-invasively reveal functional activities inside living animal bodies through the detection of visible or near-infrared light produced by bioluminescent reactions. Recently, reconstruction approaches based on deep learning have shown great potential in optical tomography modalities. However, these reports only generate data with stationary patterns of constant target number, shape, and size. The neural networks trained by these data sets are difficult to reconstruct the patterns outside the data sets. This will tremendously restrict the applications of deep learning in optical tomography reconstruction. To address this problem, a self-training strategy is proposed for BLT reconstruction in this paper. The proposed strategy can fast generate large-scale BLT data sets with random target numbers, shapes, and sizes through an algorithm named random seed growth algorithm and the neural network is automatically self-trained. In addition, the proposed strategy uses the neural network to build a map between photon densities on surface and inside the imaged object rather than an end-to-end neural network that directly infers the distribution of sources from the photon density on surface. The map of photon density is further converted into the distribution of sources through the multiplication with stiffness matrix. Simulation, phantom, and mouse studies are carried out. Results show the availability of the proposed self-training strategy.
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Nonconvex Laplacian Manifold Joint Method for Morphological Reconstruction of Fluorescence Molecular Tomography. Mol Imaging Biol 2021; 23:394-406. [PMID: 33415678 DOI: 10.1007/s11307-020-01568-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 11/02/2020] [Accepted: 11/19/2020] [Indexed: 10/22/2022]
Abstract
PURPOSE Fluorescence molecular tomography (FMT) is a promising technique for three-dimensional (3D) visualization of biomarkers in small animals. Morphological reconstruction is valuable and necessary for further applications of FMT owing to its innate requirement for knowledge of the molecular probe distributions. PROCEDURES In this study, a Laplacian manifold regularization joint ℓ1/2-norm model is proposed for morphological reconstruction and solved by a nonconvex algorithm commonly referred to as the half-threshold algorithm. The model is combined with the structural and sparsity priors to achieve the location and structure of the target. In addition, two improvement forms (truncated and hybrid truncated forms) are proposed for better morphological reconstruction. The truncated form is proposed for balancing the sharpness and smoothness of the boundary of reconstruction. A hybrid truncated form is proposed for more structural priors. To evaluate the proposed methods, three simulation studies (morphological, robust, and double target analyses) and an in vivo experiment were performed. RESULTS The proposed methods demonstrated morphological accuracy, location accuracy, and reconstruction robustness in glioma simulation studies. An in vivo experiment with an orthotopic glioma mouse model confirmed the advantages of the proposed methods. The proposed methods always yielded the best intersection of union (IoU) in simulations and in vivo experiments (mean of 0.80 IoU). CONCLUSIONS Simulation studies and in vivo experiments demonstrate that the proposed half-threshold hybrid truncated Laplacian algorithm had an improved performance compared with the comparative algorithm in terms of morphology.
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Pogue BW, Zhang R, Cao X, Jia JM, Petusseau A, Bruza P, Vinogradov SA. Review of in vivo optical molecular imaging and sensing from x-ray excitation. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-200308VR. [PMID: 33386709 PMCID: PMC7778455 DOI: 10.1117/1.jbo.26.1.010902] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 11/24/2020] [Indexed: 05/05/2023]
Abstract
SIGNIFICANCE Deep-tissue penetration by x-rays to induce optical responses of specific molecular reporters is a new way to sense and image features of tissue function in vivo. Advances in this field are emerging, as biocompatible probes are invented along with innovations in how to optimally utilize x-ray sources. AIM A comprehensive review is provided of the many tools and techniques developed for x-ray-induced optical molecular sensing, covering topics ranging from foundations of x-ray fluorescence imaging and x-ray tomography to the adaptation of these methods for sensing and imaging in vivo. APPROACH The ways in which x-rays can interact with molecules and lead to their optical luminescence are reviewed, including temporal methods based on gated acquisition and multipoint scanning for improved lateral or axial resolution. RESULTS While some known probes can generate light upon x-ray scintillation, there has been an emergent recognition that excitation of molecular probes by x-ray-induced Cherenkov light is also possible. Emission of Cherenkov radiation requires a threshold energy of x-rays in the high kV or MV range, but has the advantage of being able to excite a broad range of optical molecular probes. In comparison, most scintillating agents are more readily activated by lower keV x-ray energies but are composed of crystalline inorganic constituents, although some organic biocompatible agents have been designed as well. Methods to create high-resolution structured x-ray-optical images are now available, based upon unique scanning approaches and/or a priori knowledge of the scanned x-ray beam geometry. Further improvements in spatial resolution can be achieved by careful system design and algorithm optimization. Current applications of these hybrid x-ray-optical approaches include imaging of tissue oxygenation and pH as well as of certain fluorescent proteins. CONCLUSIONS Discovery of x-ray-excited reporters combined with optimized x-ray scan sequences can improve imaging resolution and sensitivity.
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Affiliation(s)
- Brian W. Pogue
- Thayer School of Engineering at Dartmouth, Hanover, New Hampshire, United States
- Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, United States
| | - Rongxiao Zhang
- Thayer School of Engineering at Dartmouth, Hanover, New Hampshire, United States
- Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, United States
| | - Xu Cao
- Thayer School of Engineering at Dartmouth, Hanover, New Hampshire, United States
| | - Jeremy Mengyu Jia
- Stanford University School of Medicine, Department of Radiation Oncology, Palo Alto, California, United States
| | - Arthur Petusseau
- Thayer School of Engineering at Dartmouth, Hanover, New Hampshire, United States
| | - Petr Bruza
- Thayer School of Engineering at Dartmouth, Hanover, New Hampshire, United States
| | - Sergei A. Vinogradov
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts of Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
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Algarawi M, Erkol H, Luk A, Ha S, Ünlü MB, Gulsen G, Nouizi F. Resolving tissue chromophore concentration at MRI resolution using multi-wavelength photo-magnetic imaging. BIOMEDICAL OPTICS EXPRESS 2020; 11:4244-4254. [PMID: 32923039 PMCID: PMC7449711 DOI: 10.1364/boe.397538] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/24/2020] [Accepted: 06/30/2020] [Indexed: 06/11/2023]
Abstract
Photo-magnetic imaging (PMI) is an emerging optical imaging modality that showed great performance on providing absorption maps with high resolution and quantitative accuracy. As a multi-modality technology, PMI warms up the imaged object using a near infrared laser while temperature variation is measured using magnetic resonance imaging. By probing tissue at multiple wavelengths, concentration of the main tissue chromophores such as oxy- and deoxy-hemoglobin, lipid, and water are obtained then used to derive functional parameters such as total hemoglobin concentration and relative oxygen saturation. In this paper, we present a multi-wavelength PMI system that was custom-built to host five different laser wavelengths. After recovering the high-resolution absorption maps, a least-squared minimization process was used to resolve the different chromophore concentration. The performance of the system was experimentally tested on a phantom with two different dyes. Their concentrations were successfully assessed with high spatial resolution and average accuracy of nearly 80%.
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Affiliation(s)
- Maha Algarawi
- Center for Functional Onco-Imaging, University of California Irvine, CA 92697, USA
- Department of Physics and Astronomy, University of California Irvine, CA 92697, USA
| | - Hakan Erkol
- Department of Physics, Bogazici University, Istanbul, Turkey
| | - Alex Luk
- Center for Functional Onco-Imaging, University of California Irvine, CA 92697, USA
| | | | - Mehmet B. Ünlü
- Department of Physics, Bogazici University, Istanbul, Turkey
| | - Gultekin Gulsen
- Center for Functional Onco-Imaging, University of California Irvine, CA 92697, USA
- Department of Physics and Astronomy, University of California Irvine, CA 92697, USA
- Department of Radiological Sciences, University of California Irvine, CA 92697, USA
| | - Farouk Nouizi
- Center for Functional Onco-Imaging, University of California Irvine, CA 92697, USA
- Department of Radiological Sciences, University of California Irvine, CA 92697, USA
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Lo PA, Su SP, Chiang HK. Small-animal 360-deg fluorescence diffuse optical tomography using structural prior information from ultrasound imaging. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-11. [PMID: 32129028 PMCID: PMC7052526 DOI: 10.1117/1.jbo.25.3.036001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 01/23/2020] [Indexed: 06/10/2023]
Abstract
We demonstrate dual modality of free-space fluorescence diffuse optical tomography (FDOT) and handheld ultrasound (US) imaging to reveal both functional and structural information in small animals. FDOT is a noninvasive method for examining the fluorophore inside an object from the light distribution of the surface. In FDOT, a 660-nm continuous wave diode laser was used as an excitation source and an electron-multiplying charge-coupled device (EMCCD) was used for fluorescence data acquisition. Both the laser and EMCCD were mounted on a 360-deg rotation gantry for the transmission optical data collection. The structural information is obtained from a 6- to 17-MHz handheld US linear transducer by single-side access and conducts in the reconstruction as soft priors. The rotation ranges from 0 deg to 360 deg; different rotation degrees, object positions, and parameters were determined for comparison. Both phantom and tissue phantom results demonstrate that fluorophore distribution can be recovered accurately and quantitatively using this imaging system. Finally, an animal study confirms that the system can extract a dual-modality image, validating its feasibility for further in vivo experiments. In all experiments, the error and standard deviation decrease as the rotation degree is increased and the error was reduced to 10% when the rotation degree was increased over 135 deg.
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Affiliation(s)
- Pei-An Lo
- National Yang-Ming University, Institute of Biomedical Engineering, Taipei, Taiwan
| | - Shih-Po Su
- National Yang-Ming University, Institute of Biomedical Engineering, Taipei, Taiwan
| | - Huihua Kenny Chiang
- National Yang-Ming University, Institute of Biomedical Engineering, Taipei, Taiwan
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Zhang Y, Zhang L, Yin G, Ma W, Li J, Zhou Z, Gao F. In Vivo Pharmacokinetics Assessment of Indocyanine Green-Loaded Nanoparticles in Tumor Tissue with a Dynamic Diffuse Fluorescence Tomography System. Mol Imaging Biol 2019; 21:1044-1053. [PMID: 30850969 DOI: 10.1007/s11307-019-01340-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE The purpose of this study was to show a systematic strategy for assessing the pharmacokinetics of indocyanine green (ICG)-loaded nanoparticles in the tumor tissue based on a dynamic diffuse fluorescence tomography (DFT) system. PROCEDURES Twelve-seven-week-old male Balb/c nude mice bearing HepG2/ADR hepatocellular carcinoma were randomly divided into four groups (n = 3 per group). Four hundred microliters of three types of ICG-loaded nanoparticles (content of ICG: 50 μg/ml) and free ICG (50 μg/ml) was intravenously injected into the mice in each group, respectively. Afterwards, the real-time tomographic images on the spatial level were acquired at 2-11 min, 30 min, 1, 2, 3, 4, 6, 8, 10, 12, and 24 h post-injection, and pharmacokinetic rates were derived for semi-quantitative assessment of the pharmacokinetics of nanoparticles at the tumor site using our proposed pharmacokinetic analysis method. RESULTS The results obtained from our proposed dynamic DFT experiment demonstrated the distribution of different ICG formulations on the spatial level and enabled the semi-quantitative analysis of the pharmacokinetics of nanoparticles in the tumor tissue. CONCLUSIONS The obtained pharmacokinetic rates effectively reflected the metabolic processes of nanoparticles in the tumor tissue, which proves to be beneficial for the development of tumor diagnosis and therapy.
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Affiliation(s)
- Yanqi Zhang
- School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, China
| | - Limin Zhang
- School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, China. .,Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments, Tianjin, 300072, China.
| | - Guoyan Yin
- School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, China
| | - Wenjuan Ma
- Cancer Institute and Hospital, Tianjin Medical University, Tianjin, 300060, China
| | - Jiao Li
- School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, China.,Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments, Tianjin, 300072, China
| | - Zhongxing Zhou
- School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, China.,Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments, Tianjin, 300072, China
| | - Feng Gao
- School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, China. .,Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments, Tianjin, 300072, China.
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Zhang Y, Zhang L, Yin G, Ma W, Gao F. Assessing indocyanine green pharmacokinetics in mouse liver with a dynamic diffuse fluorescence tomography system. JOURNAL OF BIOPHOTONICS 2018; 11:e201800041. [PMID: 29797547 DOI: 10.1002/jbio.201800041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/22/2018] [Indexed: 06/08/2023]
Abstract
Fluorescence pharmacokinetic rates in tissues can provide additional specific and quantitative physiological and pathological information for evaluating organ function. This modality requires a highly sensitive diffuse fluorescence tomography (DFT) working in dynamic way to finally extract the pharmacokinetic rates from the measured pharmacokinetics-associated temporally varying boundary intensity, normally with the support of a priori anatomy. This paper is devoted to study pharmacokinetics of indocyanine green (ICG) in mouse liver based on synergistic dynamic-DFT and X-ray computer tomography (XCT): A highly sensitive dynamic DFT system of CT-scanning mode working with parallel 4 photomultiplier-tube photon-counting channels generates informative and instantaneous sampling datasets; An XCT system provides priori information of the target localization for improvement of the reconstruction quality; An analysis procedure extracts the pharmacokinetic rates from the reconstructed ICG concentration-time curves, using the Gauss-Newton scheme for fitting to a 2-compartment model. The uptake and excretion rates of ICG which were obtained in livers of 10 healthy mice in the in vivo experiments can be used to quantitatively evaluate liver function. The results can validate the effectiveness of both the imaging measurements system and pharmacokinetic analysis method.
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Affiliation(s)
- Yanqi Zhang
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, China
| | - Limin Zhang
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, China
- Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments, Tianjin, China
| | - Guoyan Yin
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, China
| | - Wenjuan Ma
- Cancer Institute and Hospital, Tianjin Medical University, Tianjin, China
| | - Feng Gao
- College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, China
- Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments, Tianjin, China
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Baikejiang R, Zhao Y, Fite BZ, Ferrara KW, Li C. Anatomical image-guided fluorescence molecular tomography reconstruction using kernel method. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:55001. [PMID: 28464120 PMCID: PMC5629124 DOI: 10.1117/1.jbo.22.5.055001] [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: 01/05/2017] [Accepted: 04/10/2017] [Indexed: 05/20/2023]
Abstract
Fluorescence molecular tomography (FMT) is an important in vivo imaging modality to visualize physiological and pathological processes in small animals. However, FMT reconstruction is ill-posed and ill-conditioned due to strong optical scattering in deep tissues, which results in poor spatial resolution. It is well known that FMT image quality can be improved substantially by applying the structural guidance in the FMT reconstruction. An approach to introducing anatomical information into the FMT reconstruction is presented using the kernel method. In contrast to conventional methods that incorporate anatomical information with a Laplacian-type regularization matrix, the proposed method introduces the anatomical guidance into the projection model of FMT. The primary advantage of the proposed method is that it does not require segmentation of targets in the anatomical images. Numerical simulations and phantom experiments have been performed to demonstrate the proposed approach’s feasibility. Numerical simulation results indicate that the proposed kernel method can separate two FMT targets with an edge-to-edge distance of 1 mm and is robust to false-positive guidance and inhomogeneity in the anatomical image. For the phantom experiments with two FMT targets, the kernel method has reconstructed both targets successfully, which further validates the proposed kernel method.
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Affiliation(s)
- Reheman Baikejiang
- University of California, Merced, School of Engineering, Merced, California, United States
| | - Yue Zhao
- University of California, Merced, School of Engineering, Merced, California, United States
| | - Brett Z. Fite
- University of California, Davis, Department of Biomedical Engineering, Davis, California, United States
| | - Katherine W. Ferrara
- University of California, Davis, Department of Biomedical Engineering, Davis, California, United States
| | - Changqing Li
- University of California, Merced, School of Engineering, Merced, California, United States
- Address all correspondence to: Changqing Li, E-mail:
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A Novel Mouse Segmentation Method Based on Dynamic Contrast Enhanced Micro-CT Images. PLoS One 2017; 12:e0169424. [PMID: 28060917 PMCID: PMC5217965 DOI: 10.1371/journal.pone.0169424] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 12/17/2016] [Indexed: 11/22/2022] Open
Abstract
With the development of hybrid imaging scanners, micro-CT is widely used in locating abnormalities, studying drug metabolism, and providing structural priors to aid image reconstruction in functional imaging. Due to the low contrast of soft tissues, segmentation of soft tissue organs from mouse micro-CT images is a challenging problem. In this paper, we propose a mouse segmentation scheme based on dynamic contrast enhanced micro-CT images. With a homemade fast scanning micro-CT scanner, dynamic contrast enhanced images were acquired before and after injection of non-ionic iodinated contrast agents (iohexol). Then the feature vector of each voxel was extracted from the signal intensities at different time points. Based on these features, the heart, liver, spleen, lung, and kidney could be classified into different categories and extracted from separate categories by morphological processing. The bone structure was segmented using a thresholding method. Our method was validated on seven BALB/c mice using two different classifiers: a support vector machine classifier with a radial basis function kernel and a random forest classifier. The results were compared to manual segmentation, and the performance was assessed using the Dice similarity coefficient, false positive ratio, and false negative ratio. The results showed high accuracy with the Dice similarity coefficient ranging from 0.709 ± 0.078 for the spleen to 0.929 ± 0.006 for the kidney.
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14
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Zhang X, Zhang J, Luo J. Reconstruction of in vivo fluorophore concentration variation with structural priors and smooth penalty. APPLIED OPTICS 2016; 55:2732-2740. [PMID: 27139679 DOI: 10.1364/ao.55.002732] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Reconstruction of fluorophore concentration variation in fluorescence molecular tomography is expected to reveal the metabolic processes of fluorescent biomarkers in vivo. However, the complicated and strong noise within in vivo data inhibits its applications for in vivo cases. A smooth penalty method is presented in this work to suppress the noise. The method is based on a recursive reconstruction scheme which reconstructs the fluorophore concentration variation rates (FCVRs) of two neighboring frames at the same time within an inner iteration. In addition, the performance of the Laplacian-type regularization incorporating structural priors is investigated. Results of simulations suggest that the smooth penalty method almost has no influence on the reconstructed FCVRs when the target curve is smooth, and results of in vivo experiments on mice indicate that the method is capable of suppressing the noise and achieving smooth time courses of fluorescent yield. Results of both the simulations and in vivo experiments demonstrate that the Laplacian-type regularization can improve the image quality.
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15
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Mohajerani P, Ntziachristos V. An Inversion Scheme for Hybrid Fluorescence Molecular Tomography Using a Fuzzy Inference System. IEEE TRANSACTIONS ON MEDICAL IMAGING 2016; 35:381-390. [PMID: 26340771 DOI: 10.1109/tmi.2015.2475356] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The imaging performance of fluorescence molecular tomography (FMT) improves when information from the underlying anatomy is incorporated into the inversion scheme, in the form of priors. The requirement for incorporation of priors has recently driven the development of hybrid FMT systems coupled to other modalities, such as X-ray CT and MRI. A critical methodological aspect in this modality relates to the particular method selected to incorporate prior information obtained from the anatomical imaging modality into the FMT inversion. We propose herein a new approach for utilizing prior information, which preferentially minimizes residual errors associated with measurements that better describe the anatomical segments considered. This preferential minimization was realized using a weighted least square (WLS) approach, where the weights were optimized using a Mamdani-type fuzzy inference system. The method of priors introduced herein was deployed as a two-step structured regularization approach and was verified with experimental measurements from phantoms as well as ex vivo and in vivo animal studies. The results demonstrate accurate performance and minimization of reconstruction bias, without requiring user input for setting the regularization parameters. As such, the proposed method offers significant progress in incorporation of anatomical priors in FMT and, as a result, in realization of the full potential of hybrid FMT.
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16
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Correia T, Koch M, Ale A, Ntziachristos V, Arridge S. Patch-based anisotropic diffusion scheme for fluorescence diffuse optical tomography--part 2: image reconstruction. Phys Med Biol 2016; 61:1452-75. [PMID: 26808190 DOI: 10.1088/0031-9155/61/4/1452] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Fluorescence diffuse optical tomography (fDOT) provides 3D images of fluorescence distributions in biological tissue, which represent molecular and cellular processes. The image reconstruction problem is highly ill-posed and requires regularisation techniques to stabilise and find meaningful solutions. Quadratic regularisation tends to either oversmooth or generate very noisy reconstructions, depending on the regularisation strength. Edge preserving methods, such as anisotropic diffusion regularisation (AD), can preserve important features in the fluorescence image and smooth out noise. However, AD has limited ability to distinguish an edge from noise. We propose a patch-based anisotropic diffusion regularisation (PAD), where regularisation strength is determined by a weighted average according to the similarity between patches around voxels within a search window, instead of a simple local neighbourhood strategy. However, this method has higher computational complexity and, hence, we wavelet compress the patches (PAD-WT) to speed it up, while simultaneously taking advantage of the denoising properties of wavelet thresholding. Furthermore, structural information can be incorporated into the image reconstruction with PAD-WT to improve image quality and resolution. In this case, the weights used to average voxels in the image are calculated using the structural image, instead of the fluorescence image. The regularisation strength depends on both structural and fluorescence images, which guarantees that the method can preserve fluorescence information even when it is not structurally visible in the anatomical images. In part 1, we tested the method using a denoising problem. Here, we use simulated and in vivo mouse fDOT data to assess the algorithm performance. Our results show that the proposed PAD-WT method provides high quality and noise free images, superior to those obtained using AD.
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Affiliation(s)
- Teresa Correia
- Centre for Medical Imaging Computing, Department of Computer Science, University College London, Gower Street, London WC1 E6BT, UK
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17
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Morscher S, Driessen WH, Claussen J, Burton NC. Semi-quantitative Multispectral Optoacoustic Tomography (MSOT) for volumetric PK imaging of gastric emptying. PHOTOACOUSTICS 2014; 2:103-10. [PMID: 25431754 PMCID: PMC4244636 DOI: 10.1016/j.pacs.2014.06.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 04/17/2014] [Accepted: 06/18/2014] [Indexed: 05/08/2023]
Abstract
A common side effect of medication is gastrointestinal intolerance. Symptoms can include reduced appetite, diarrhea, constipation, GI inflammation, nausea and vomiting. Such effects often have a dramatic impact on compliance with a treatment regimen. Therefore, characterization of GI tolerance is an important step when establishing a novel therapeutic approach. In this study, Multispectral Optoacoustic Tomography (MSOT) is used to monitor gastrointestinal motility by in vivo whole body imaging in mice. MSOT combines high spatial and temporal resolution based on ultrasound detection with strong optical contrast in the near infrared. Animals were given Indocyanine Green (ICG) by oral gavage and imaged by MSOT to observe the fate of ICG in the gastrointestinal tract. Exponential decay of ICG signal was observed in the stomach in good correlation with ex vivo validation. We discuss how kinetic imaging in MSOT allows visualization of parameters unavailable to other imaging methods, both in 2D and 3D.
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18
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Zhang J, Shi J, Cao X, Liu F, Bai J, Luo J. Fast reconstruction of fluorescence molecular tomography via a permissible region extraction strategy. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2014; 31:1886-1894. [PMID: 25121547 DOI: 10.1364/josaa.31.001886] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In order to obtain precise reconstruction results in fluorescence molecular tomography (FMT), large-scale matrix equations would be solved in the inverse problem generally. Thus, much time and memory needs to be consumed. In this paper, a permissible region extraction strategy is proposed to solve this problem. First, a preliminary result is rapidly reconstructed using the weight matrix compressed by principal component analysis or uniform sampling. And then the reconstructed target area in this preliminary result is considered as the a priori permissible region to guide the final reconstruction. Phantom experiments with double fluorescent targets are performed to test the performance of the strategy. The results illustrate that the proposed strategy can significantly accelerate the image reconstruction in FMT almost without quality degradation.
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19
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Lee JH, Kim HK, Chandhanayingyong C, Lee FYI, Hielscher AH. Non-contact small animal fluorescence imaging system for simultaneous multi-directional angular-dependent data acquisition. BIOMEDICAL OPTICS EXPRESS 2014; 5:2301-16. [PMID: 25071965 PMCID: PMC4102365 DOI: 10.1364/boe.5.002301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 05/23/2014] [Accepted: 05/24/2014] [Indexed: 05/05/2023]
Abstract
We present a novel non-contact small animal fluorescent molecular tomography (FMT) imaging system. At the heart of the system is a new mirror-based imaging head that was designed to provide 360-degree measurement data from an entire animal surface in one step. This imaging head consists of two conical mirrors, which considerably reduce multiple back reflections between the animal and mirror surfaces. These back reflections are common in existing mirror-based imaging heads and tend to degrade the quality of raw measurement data. In addition, the introduction of a novel ray-transfer operator allows for the inclusion of the angular dependent data in the image reconstruction process, which results in higher image resolution. We describe in detail the system design and implementation of the hardware components as well as the transport-theory-based image reconstruction algorithm. Using numerical simulations, measurements on a well-defined phantom and a live animal, we evaluate the system performance and show the advantages of our approach.
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Affiliation(s)
- Jong Hwan Lee
- Department of Biomedical Engineering, Columbia University, 351 Engineering Terrace Mudd building, 500 West 120th Street, New York, NY, 10027, USA
| | - Hyun Keol Kim
- Department of Radiology, Columbia University Medical Center, 180 Fort Washington Avenue, New York, NY, 10032, USA
| | | | - Francis Young-In Lee
- Department of Orthopedic Surgery, Columbia University Medical Center, 650 West 168th Street, New York, NY, 10032, USA
| | - Andreas H. Hielscher
- Department of Biomedical Engineering, Columbia University, 351 Engineering Terrace Mudd building, 500 West 120th Street, New York, NY, 10027, USA
- Department of Radiology, Columbia University Medical Center, 180 Fort Washington Avenue, New York, NY, 10032, USA
- Department of Electrical Engineering, Columbia University, 1300 S. W. Mudd Building, 500 West 120th Street, New York, NY, 10027, USA
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20
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Li B, Berti R, Abran M, Lesage F. Ultrasound guided fluorescence molecular tomography with improved quantification by an attenuation compensated Born-normalization and in vivo preclinical study of cancer. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:053703. [PMID: 24880378 DOI: 10.1063/1.4875256] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Ultrasound imaging, having the advantages of low-cost and non-invasiveness over MRI and X-ray CT, was reported by several studies as an adequate complement to fluorescence molecular tomography with the perspective of improving localization and quantification of fluorescent molecular targets in vivo. Based on the previous work, an improved dual-modality Fluorescence-Ultrasound imaging system was developed and then validated in imaging study with preclinical tumor model. Ultrasound imaging and a profilometer were used to obtain the anatomical prior information and 3D surface, separately, to precisely extract the tissue boundary on both sides of sample in order to achieve improved fluorescence reconstruction. Furthermore, a pattern-based fluorescence reconstruction on the detection side was incorporated to enable dimensional reduction of the dataset while keeping the useful information for reconstruction. Due to its putative role in the current imaging geometry and the chosen reconstruction technique, we developed an attenuation compensated Born-normalization method to reduce the attenuation effects and cancel off experimental factors when collecting quantitative fluorescence datasets over large area. Results of both simulation and phantom study demonstrated that fluorescent targets could be recovered accurately and quantitatively using this reconstruction mechanism. Finally, in vivo experiment confirms that the imaging system associated with the proposed image reconstruction approach was able to extract both functional and anatomical information, thereby improving quantification and localization of molecular targets.
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Affiliation(s)
- Baoqiang Li
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, Quebec H3C 3A7, Canada
| | - Romain Berti
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, Quebec H3C 3A7, Canada
| | - Maxime Abran
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, Quebec H3C 3A7, Canada
| | - Frédéric Lesage
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, Quebec H3C 3A7, Canada
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21
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Li B, Maafi F, Berti R, Pouliot P, Rhéaume E, Tardif JC, Lesage F. Hybrid FMT-MRI applied to in vivo atherosclerosis imaging. BIOMEDICAL OPTICS EXPRESS 2014; 5:1664-76. [PMID: 24877023 PMCID: PMC4026902 DOI: 10.1364/boe.5.001664] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 04/24/2014] [Accepted: 04/24/2014] [Indexed: 05/20/2023]
Abstract
Combining Fluorescent Molecular Tomography (FMT) with anatomical imaging, e.g. MRI facilitates interpreting functional information. Furthermore, using a heterogeneous model for light propagation has been shown in simulations to be superior to homogeneous modeling to quantify fluorescence. Here, we present a combined FMT-MRI system and apply it to heart and aorta molecular imaging, a challenging area due to strong tissue heterogeneity and the presence of air-voids due to lungs. First investigating performance in a phantom and mouse corpse, the MRI-enabled heterogeneous models resulted in an improved quantification of fluorescence reconstructions. The system was then used in mice for in vivo atherosclerosis molecular imaging. Results show that, when using the heterogeneous model, reconstructions were in agreement with the ex vivo measurements. Therefore, the proposed system might serve as a powerful imaging tool for atherosclerosis in mice.
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Affiliation(s)
- Baoqiang Li
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, QC, H3C 3A7, Canada
- Montreal Heart Institute, Montreal, QC, H1T 1C8, Canada
| | - Foued Maafi
- Montreal Heart Institute, Montreal, QC, H1T 1C8, Canada
| | - Romain Berti
- Montreal Heart Institute, Montreal, QC, H1T 1C8, Canada
| | - Philippe Pouliot
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, QC, H3C 3A7, Canada
- Montreal Heart Institute, Montreal, QC, H1T 1C8, Canada
| | - Eric Rhéaume
- Montreal Heart Institute, Montreal, QC, H1T 1C8, Canada
| | | | - Frederic Lesage
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, QC, H3C 3A7, Canada
- Montreal Heart Institute, Montreal, QC, H1T 1C8, Canada
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22
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Radrich K, Mohajerani P, Bussemer J, Schwaiger M, Beer AJ, Ntziachristos V. Limited-projection-angle hybrid fluorescence molecular tomography of multiple molecules. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:046016. [PMID: 24770661 DOI: 10.1117/1.jbo.19.4.046016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 03/25/2014] [Indexed: 06/03/2023]
Abstract
An advantage of fluorescence methods over other imaging modalities is the ability to concurrently resolve multiple moieties using fluorochromes emitting at different spectral regions. Simultaneous imaging of spectrally separated agents is helpful in interrogating multiple functions or establishing internal controls for accurate measurements. Herein, we investigated multimoiety imaging in the context of a limited-projection-angle hybrid fluorescence molecular tomography (FMT), and x-ray computed tomography implementation and the further registration with positron emission tomography (PET) data. Multichannel FMT systems may image fluorescent probes of varying distribution patterns. Therefore, it is possible that different channels may require different use of priors and regularization parameters. We examined the performance of automatically estimating regularization factors implementing priors, using data-driven regularization specific for limited-projection-angle schemes. We were particularly interested in identifying the implementation variations between hybrid-FMT channels due to probe distribution variation. For this reason, initial validation of the data-driven algorithm on a phantom was followed by imaging different agent distributions in animals, assuming superficial and deep seated activity. We further demonstrate the benefits of combining hybrid FMT with PET to gain multiple readings on the molecular composition of disease.
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Affiliation(s)
- Karin Radrich
- Institute for Biological and Medical Imaging, Helmholtz Zentrum München, Ingolstaedter Landstrasse 1, D-85764 Neuherberg, GermanybTechnische Universität München, Chair for Biological Imaging, Ismaninger Strasse 22, D-81675 Munich, Germany
| | - Pouyan Mohajerani
- Institute for Biological and Medical Imaging, Helmholtz Zentrum München, Ingolstaedter Landstrasse 1, D-85764 Neuherberg, GermanybTechnische Universität München, Chair for Biological Imaging, Ismaninger Strasse 22, D-81675 Munich, Germany
| | - Johanna Bussemer
- Technische Universität München, Department of Nuclear Medicine, Ismaninger Strasse 22, D-81675 Munich, Germany
| | - Markus Schwaiger
- Technische Universität München, Department of Nuclear Medicine, Ismaninger Strasse 22, D-81675 Munich, Germany
| | - Ambros J Beer
- Technische Universität München, Department of Nuclear Medicine, Ismaninger Strasse 22, D-81675 Munich, Germany
| | - Vasilis Ntziachristos
- Institute for Biological and Medical Imaging, Helmholtz Zentrum München, Ingolstaedter Landstrasse 1, D-85764 Neuherberg, GermanybTechnische Universität München, Chair for Biological Imaging, Ismaninger Strasse 22, D-81675 Munich, Germany
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23
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Abstract
Diffuse optical imaging is highly versatile and has a very broad range of applications in biology and medicine. It covers diffuse optical tomography, fluorescence diffuse optical tomography, bioluminescence, and a number of other new imaging methods. These methods of diffuse optical imaging have diversified instrument configurations but share the same core physical principle – light propagation in highly diffusive media, i.e., the biological tissue. In this review, the author summarizes the latest development in instrumentation and methodology available to diffuse optical imaging in terms of system architecture, light source, photo-detection, spectral separation, signal modulation, and lastly imaging contrast.
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24
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Zhang B, Gao F, Wang M, Cao X, Liu F, Wang X, Luo J, Wang G, Bai J. In vivo tomographic imaging of lung colonization of tumour in mouse with simultaneous fluorescence and X-ray CT. JOURNAL OF BIOPHOTONICS 2014; 7:110-116. [PMID: 23696158 DOI: 10.1002/jbio.201300037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 04/01/2013] [Accepted: 04/29/2013] [Indexed: 06/02/2023]
Abstract
Non-invasive in vivo imaging of diffuse and wide-spread colonization within the lungs, rather than distinct solid primary tumors, is still a challenging work. In this work, a lung colonization mouse model bearing A549 human lung tumor was simultaneously scanned by a dual-modality fluorescence molecular tomography (FMT) and X-ray computed tomography (CT) system in vivo. A two steps method which incorporates CT structural information into the FMT reconstruction procedure is employed to provide concurrent anatomical and functional information. By using the target-specific fluorescence agent, the fluorescence tomographic results show elevated fluorescence intensity deep within the lungs which is colonized with diffuse and wide-spread tumors. The results were confirmed with ex vivo fluorescence reflectance imaging and histological examination of the lung tissues. With FMT reconstruction combined with the CT information, the dual-modality FMT/micro-CT system is expected to offer sensitive and noninvasive imaging of diffuse tumor colonization within the lungs in vivo.
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Affiliation(s)
- Bin Zhang
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, 100084, China
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25
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Ale A, Siebenhaar F, Kosanke K, Aichler M, Radrich K, Heydrich S, Schiemann M, Bielicki I, Noel PB, Braren R, Maurer M, Walch AK, Rummeny EJ, Ntziachristos V, Wildgruber M. Cardioprotective C-kit⁺ bone marrow cells attenuate apoptosis after acute myocardial infarction in mice - in-vivo assessment with fluorescence molecular imaging. Theranostics 2013; 3:903-13. [PMID: 24312159 PMCID: PMC3841340 DOI: 10.7150/thno.5938] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 04/28/2013] [Indexed: 11/05/2022] Open
Abstract
Cardiomyocyte loss via apoptosis plays a crucial role in ventricular remodeling following myocardial infarction (MI). Cell-based therapy approaches using bone marrow derived c-kit⁺ pluripotent cells may attenuate apoptosis following ischemic injury. We therefore thought to examine the early course of apoptosis following myocardial infarction - in-vivo - and non-invasively determine the effect of c-kit⁺ bone marrow cells on post-MI remodeling. We studied apoptosis in wild-type Kit(+/+) , c-kit mutant Kit(W)/Kit(W-v) and Kit(W)/Kit(W-v) mice after cell therapy with bone-marrow derived c-kit⁺ cells after ischemia-reperfusion injury. Mice were followed by hybrid Fluorescence Molecular Tomography/X-ray Computed Tomography (FMT-XCT) at 6h, 24h and 7 days after ischemia-reperfusion injury using an Annexin V-based fluorescent nanosensor targeting phosphatidylserine. Kit(W)/Kit(W-v) mice showed increased and prolonged apoptosis compared to control Kit(+/+) mice while c-kit cell therapy was able to attenuate the altered apoptosis rates. Increased apoptosis was accompanied by severe decline in heart function, determined by cardiac Magnetic Resonance Imaging, and cell therapy was able to rescue the animals from deleterious heart failure. Post-mortem cryoslicing and immunohistochemistry localized the fluorescence signal of the Annexin V sensor within the infarcted myocardium. Flow cytometry of digested infarct specimens identified apoptotic cardiomyocytes as the major source for the in-vivo Annexin V signal. In-vivo molecular imaging using hybrid FMT-XCT reveals increased cardiomyocyte apoptosis in Kit(W)/Kit(W-v) mice and shows that c-kit⁺ cardioprotective cells are able to attenuate post-MI apoptosis and rescue mice from progressive heart failure.
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26
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Wildgruber M, Swirski FK, Zernecke A. Molecular imaging of inflammation in atherosclerosis. Am J Cancer Res 2013; 3:865-84. [PMID: 24312156 PMCID: PMC3841337 DOI: 10.7150/thno.5771] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 04/29/2013] [Indexed: 01/13/2023] Open
Abstract
Acute rupture of vulnerable plaques frequently leads to myocardial infarction and stroke. Within the last decades, several cellular and molecular players have been identified that promote atherosclerotic lesion formation, maturation and plaque rupture. It is now widely recognized that inflammation of the vessel wall and distinct leukocyte subsets are involved throughout all phases of atherosclerotic lesion development. The mechanisms that render a stable plaque unstable and prone to rupture, however, remain unknown and the identification of the vulnerable plaque remains a major challenge in cardiovascular medicine. Imaging technologies used in the clinic offer minimal information about the underlying biology and potential risk for rupture. New imaging technologies are therefore being developed, and in the preclinical setting have enabled new and dynamic insights into the vessel wall for a better understanding of this complex disease. Molecular imaging has the potential to track biological processes, such as the activity of cellular and molecular biomarkers in vivo and over time. Similarly, novel imaging technologies specifically detect effects of therapies that aim to stabilize vulnerable plaques and silence vascular inflammation. Here we will review the potential of established and new molecular imaging technologies in the setting of atherosclerosis, and discuss the cumbersome steps required for translating molecular imaging approaches into the clinic.
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27
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Holt RW, Davis S, Pogue BW. Regularization functional semi-automated incorporation of anatomical prior information in image-guided fluorescence tomography. OPTICS LETTERS 2013; 38:2407-9. [PMID: 23939063 DOI: 10.1364/ol.38.002407] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The use of anatomical priors in fluorescence tomography is known to improve image quality and accuracy significantly. However, the use of prior information is often implemented by incorporating user segmented structural images into the optical reconstruction algorithm, a process requiring significant time and expertise. We propose an automated implementation which encodes the gray-scale prior image directly into the regularization term, eliminating the need for direct prior image segmentation, which is extendable to any spatially defined prior data. The proposed method is supported by in vivo studies.
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Affiliation(s)
- Robert W Holt
- Department of Physics and Astronomy, Dartmouth College, New Hampshire 03755, USA.
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28
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Mohajerani P, Ntziachristos V. Compression of Born ratio for fluorescence molecular tomography/x-ray computed tomography hybrid imaging: methodology and in vivo validation. OPTICS LETTERS 2013; 38:2324-2326. [PMID: 23811916 DOI: 10.1364/ol.38.002324] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The 360° rotation geometry of the hybrid fluorescence molecular tomography/x-ray computed tomography modality allows for acquisition of very large datasets, which pose numerical limitations on the reconstruction. We propose a compression method that takes advantage of the correlation of the Born-normalized signal among sources in spatially formed clusters to reduce the size of system model. The proposed method has been validated using an ex vivo study and an in vivo study of a nude mouse with a subcutaneous 4T1 tumor, with and without inclusion of a priori anatomical information. Compression rates of up to two orders of magnitude with minimum distortion of reconstruction have been demonstrated, resulting in large reduction in weight matrix size and reconstruction time.
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Affiliation(s)
- Pouyan Mohajerani
- Institute for Biological and Medical Imaging, Technische Universität München and Helmholtz Zentrum München, Ingolstädter Landstrasse 1, Neuherberg 85764, Germany
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29
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Ermolayev V, Cohrs CM, Mohajerani P, Ale A, Hrabé de Angelis M, Ntziachristos V. Ex-vivo assessment and non-invasive in vivo imaging of internal hemorrhages in Aga2/+ mutant mice. Biochem Biophys Res Commun 2013; 432:389-93. [PMID: 23333738 DOI: 10.1016/j.bbrc.2013.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 01/05/2013] [Indexed: 10/27/2022]
Abstract
Mutations in type I collagen genes (COL1A1/2) typically lead to Osteogenesis imperfecta, the most common heritable cause of skeletal fractures and bone deformation in humans. Heterozygous Col1a1(Aga2/+), animals with a dominant mutation in the terminal C-propeptide domain of type I collagen develop typical skeletal hallmarks and internal hemorrhages starting from 6 day after birth. The disease progression for Aga2/+ mice, however, is not uniform differing between severe phenotype lethal at the 6-11th day of life, and moderate-to-severe one with survival to adulthood. Herein we investigated whether a new modality that combines X-ray computer tomography with fluorescence tomography in one hybrid system can be employed to study internal bleedings in relation to bone fractures and obtain insights into disease progression. The disease phenotype was characterized on Aga2/+ vs. wild type mice between 6 and 9 days postnatal. Anatomical and functional findings obtained in-vivo were contrasted to the ex-vivo appearance of the same tissues under cryo-slicing.
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Affiliation(s)
- Vladimir Ermolayev
- Institute for Biological and Medical Imaging, Helmholtz Zentrum München, Building 56, Ingolstädter Landstraße 1, D-85764 Neuherberg, Germany
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30
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Venugopal V, Intes X. Adaptive wide-field optical tomography. JOURNAL OF BIOMEDICAL OPTICS 2013; 18:036006. [PMID: 23475290 PMCID: PMC3591745 DOI: 10.1117/1.jbo.18.3.036006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2012] [Revised: 02/02/2013] [Accepted: 02/05/2013] [Indexed: 05/20/2023]
Abstract
We describe a wide-field optical tomography technique, which allows the measurement-guided optimization of illumination patterns for enhanced reconstruction performances. The iterative optimization of the excitation pattern aims at reducing the dynamic range in photons transmitted through biological tissue. It increases the number of measurements collected with high photon counts resulting in a dataset with improved tomographic information. Herein, this imaging technique is applied to time-resolved fluorescence molecular tomography for preclinical studies. First, the merit of this approach is tested by in silico studies in a synthetic small animal model for typical illumination patterns. Second, the applicability of this approach in tomographic imaging is validated in vitro using a small animal phantom with two fluorescent capillaries occluded by a highly absorbing inclusion. The simulation study demonstrates an improvement of signal transmitted (∼2 orders of magnitude) through the central portion of the small animal model for all patterns considered. A corresponding improvement in the signal at the emission wavelength by 1.6 orders of magnitude demonstrates the applicability of this technique for fluorescence molecular tomography. The successful discrimination and localization (∼1 mm error) of the two objects with higher resolution using the optimized patterns compared with nonoptimized illumination establishes the improvement in reconstruction performance when using this technique.
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Affiliation(s)
- Vivek Venugopal
- Rensselaer Polytechnic Institute, Department of Biomedical Engineering, 110 8th Street, Troy, New York 12180
| | - Xavier Intes
- Rensselaer Polytechnic Institute, Department of Biomedical Engineering, 110 8th Street, Troy, New York 12180
- Address all correspondence to: Xavier Intes, Rensselaer Polytechnic Institute, Department of Biomedical Engineering, 110 8th Street, Troy, New York 12180. Tel: (518) 276-6964; E-mail:
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31
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Abstract
Since the inception of the microscope, optical imaging is serving the biological discovery for more than four centuries. With the recent emergence of methods appropriate for in vivo staining, such as bioluminescence, fluorescent molecular probes, and proteins, as well as nanoparticle-based targeted agents, significant attention has been shifted toward in vivo interrogations of different dynamic biological processes at the molecular level. This progress has been largely supported by the development of advanced optical tomographic imaging technologies suitable for obtaining volumetric visualization of biomarker distributions in small animals at a whole-body or whole-organ scale, an imaging frontier that is not accessible by the existing tissue-sectioning microscopic techniques due to intensive light scattering beyond the depth of a few hundred microns. Biomedical optoacoustics has also emerged in the recent decade as a powerful tool for high-resolution visualization of optical contrast, overcoming a variety of longstanding limitations imposed by light scattering in deep tissues. By detecting tiny sound vibrations, resulting from selective absorption of light at multiple wavelengths, multispectral optoacoustic tomography methods can now "hear color" in three dimensions, i.e., deliver volumetric spectrally enriched (color) images from deep living tissues at high spatial resolution and in real time. These new-found imaging abilities directly relate to preclinical screening applications in animal models and are foreseen to significantly impact clinical decision making as well.
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Affiliation(s)
- Vasilis Ntziachristos
- Institute for Biological and Medical Imaging,Technische Universität München and Helmholtz Zentrum München, Munich, Germany.
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32
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Pu H, He W, Zhang G, Zhang B, Liu F, Zhang Y, Luo J, Bai J. Separating structures of different fluorophore concentrations by principal component analysis on multispectral excitation-resolved fluorescence tomography images. BIOMEDICAL OPTICS EXPRESS 2013; 4:1829-45. [PMID: 24156047 PMCID: PMC3799649 DOI: 10.1364/boe.4.001829] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 08/01/2013] [Accepted: 08/05/2013] [Indexed: 05/03/2023]
Abstract
Multispectral excitation-resolved fluorescence tomography (MEFT) uses excitation light of different wavelengths to illuminate the fluorophores and obtains the reconstruction image frame which is fluorescence yield at each corresponding wavelength. For structures containing fluorophores of different concentrations, fluorescence yields show different variation trends with the excitation spectrum. In this study, principal component analysis (PCA) is used to analyze the MEFT reconstructed image frames. By taking advantage of the different variation trends of fluorescence yields, PCA can provide a set of principal components (PCs) in which structures containing different concentrations of fluorophores are shown separately. Simulations and experiments are both performed to test the performance of the proposed algorithm. The results suggest that the location and structure of fluorophores with different concentrations can be obtained and the contrast of fluorophores can be improved further by using this algorithm.
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Affiliation(s)
- Huangsheng Pu
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
- Department of Computer Application, School of Biomedical Engineering, Fourth Military Medical University, Xi’an710032, China
| | - Wei He
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Guanglei Zhang
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Bin Zhang
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Fei Liu
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Yi Zhang
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Jianwen Luo
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
- Center for Biomedical Imaging Research, Tsinghua University, Beijing 100084, China
| | - Jing Bai
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
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33
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Lin Y, Ghijsen M, Nalcioglu O, Gulsen G. In vivo validation of quantitative frequency domain fluorescence tomography. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:126021. [PMID: 23323291 PMCID: PMC3525318 DOI: 10.1117/1.jbo.17.12.126021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We have developed a hybrid frequency domain fluorescence tomography and magnetic resonance imaging system (MRI) for small animal imaging. The main purpose of this system is to obtain quantitatively accurate fluorescence concentration and lifetime images using a multi-modality approach. In vivo experiments are undertaken to evaluate the system. We compare the recovered fluorescence parameters with and without MRI structural a priori information. In addition, we compare two optical background heterogeneity correction methods: Born normalization and utilizing diffuse optical tomography (DOT) functional a priori information. The results show that the concentration and lifetime of a 4.2-mm diameter indocyanine green inclusion located 15 mm deep inside a rat can be recovered with less than a 5% error when functional a priori information from DOT and structural a priori information from MRI are utilized.
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Affiliation(s)
- Yuting Lin
- University of California, Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, 164 Irvine Hall, Irvine, California 92697
| | - Michael Ghijsen
- University of California, Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, 164 Irvine Hall, Irvine, California 92697
| | - Orhan Nalcioglu
- University of California, Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, 164 Irvine Hall, Irvine, California 92697
| | - Gultekin Gulsen
- University of California, Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, 164 Irvine Hall, Irvine, California 92697
- Address all correspondence to: Gultekin Gulsen, University of California, Tu and Yuen Center for Functional Onco-Imaging, 164 Irvine Hall, Irvine, California 92697. Tel: 949 824 6557; Fax: 949 824 3481; E-mail:
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Abstract
OBJECTIVE Optical imaging is experiencing significant technologic advances. Simultaneously, an array of specific optical imaging agents has brought new capabilities to biomedical research and is edging toward clinical use. We review progress in the translation of macroscopic optical imaging-including fluorescence-guided surgery and endoscopy, intravascular fluorescence imaging, diffuse fluorescence and optical tomography, and multispectral optoacoustics (photoacoustics)-for applications ranging from tumor resection and assessment of atherosclerotic plaques to dermatologic and breast examinations. CONCLUSION Optical imaging could play a major role in the move from imaging of structure and morphology to the visualization of the individual biologic processes underlying disease and could, therefore, contribute to more accurate diagnostics and improved treatment efficacy.
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Lin Y, Bolisay L, Ghijsen M, Kwong TC, Gulsen G. Temperature-modulated fluorescence tomography in a turbid media. APPLIED PHYSICS LETTERS 2012; 100:73702-737024. [PMID: 22393266 PMCID: PMC3292592 DOI: 10.1063/1.3681378] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 01/05/2012] [Indexed: 05/25/2023]
Abstract
High scattering in biological tissues makes fluorescence tomography inverse problem very challenging in thick medium. We describe an approach termed "temperature-modulated fluorescence tomography" that can acquire fluorescence images at focused ultrasound resolution. By utilizing recently emerged temperature sensitive fluorescence contrast agents, this technique provides fluorescence images with high resolution prior to any reconstruction process. We demonstrate that this technique is well suited to resolve small fluorescence targets located several centimeters deep in tissue.
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36
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Li B, Abran M, Matteau-Pelletier C, Rouleau L, Lam T, Sharma R, Rhéaume E, Kakkar A, Tardif JC, Lesage F. Low-cost three-dimensional imaging system combining fluorescence and ultrasound. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:126010. [PMID: 22191927 DOI: 10.1117/1.3662455] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
In this paper, we present a dual-modality imaging system combining three-dimensional (3D) continuous-wave transillumination fluorescence tomography with 3D ultrasound (US) imaging. We validated the system with two phantoms, one containing fluorescent inclusions (Cy5.5) at different depths, and another varying-thickness semicylindrical phantom. Using raster scanning, the combined fluorescence/US system was used to collect the boundary fluorescent emission in the X-Y plane, as well as recovered the 3D surface and position of the inclusions from US signals. US images were segmented to provide soft priors for the fluorescence image reconstruction. Phantom results demonstrated that with priors derived from the US images, the fluorescent reconstruction quality was significantly improved. As further evaluation, we show pilot in vivo results using an Apo-E mouse to assess the feasibility and performance of this system in animal studies. Limitations and potential to be used in artherosclerosis studies are then discussed.
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Affiliation(s)
- Baoqiang Li
- École Polytechnique de Montréal, Institute of Biomedical Engineering, Montreal, H3C 3A7, Canada
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Pogue BW, Davis SC, Leblond F, Mastanduno MA, Dehghani H, Paulsen KD. Implicit and explicit prior information in near-infrared spectral imaging: accuracy, quantification and diagnostic value. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2011; 369:4531-57. [PMID: 22006905 PMCID: PMC3263784 DOI: 10.1098/rsta.2011.0228] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Near-infrared spectroscopy (NIRS) of tissue provides quantification of absorbers, scattering and luminescent agents in bulk tissue through the use of measurement data and assumptions. Prior knowledge can be critical about things such as (i) the tissue shape and/or structure, (ii) spectral constituents, (iii) limits on parameters, (iv) demographic or biomarker data, and (v) biophysical models of the temporal signal shapes. A general framework of NIRS imaging with prior information is presented, showing that prior information datasets could be incorporated at any step in the NIRS process, with the general workflow being: (i) data acquisition, (ii) pre-processing, (iii) forward model, (iv) inversion/reconstruction, (v) post-processing, and (vi) interpretation/diagnosis. Most of the development in NIRS has used ad hoc or empirical implementations of prior information such as pre-measured absorber or fluorophore spectra, or tissue shapes as estimated by additional imaging tools. A comprehensive analysis would examine what prior information maximizes the accuracy in recovery and value for medical diagnosis, when implemented at separate stages of the NIRS sequence. Individual applications of prior information can show increases in accuracy or improved ability to estimate biochemical features of tissue, while other approaches may not. Most beneficial inclusion of prior information has been in the inversion/reconstruction process, because it solves the mathematical intractability. However, it is not clear that this is always the most beneficial stage.
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Affiliation(s)
- Brian W Pogue
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA.
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38
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Fu J, Yang X, Wang K, Luo Q, Gong H. A generic, geometric cocalibration method for a combined system of fluorescence molecular tomography and microcomputed tomography with arbitrarily shaped objects. Med Phys 2011; 38:6561-70. [DOI: 10.1118/1.3658727] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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39
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Li C, Yang Y, Mitchell GS, Cherry SR. Simultaneous PET and multispectral 3-dimensional fluorescence optical tomography imaging system. J Nucl Med 2011; 52:1268-75. [PMID: 21810591 DOI: 10.2967/jnumed.110.082859] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
UNLABELLED Integrated PET and 3-dimensional (3D) fluorescence optical tomography (FOT) imaging has unique and attractive features for in vivo molecular imaging applications. We have designed, built, and evaluated a simultaneous PET and 3D FOT system. The design of the FOT system is compatible with many existing small-animal PET scanners. METHODS The 3D FOT system comprises a novel conical mirror that is used to view the whole-body surface of a mouse with an electron-multiplying charge-coupled device camera when a collimated laser beam is projected on the mouse to stimulate fluorescence. The diffusion equation was used to model the propagation of optical photons inside the mouse body, and 3D fluorescence images were reconstructed iteratively from the fluorescence intensity measurements measured from the surface of the mouse. Insertion of the conical mirror into the gantry of a small-animal PET scanner allowed simultaneous PET and 3D FOT imaging. RESULTS The mutual interactions between PET and 3D FOT were evaluated experimentally. PET has negligible effects on 3D FOT performance. The inserted conical mirror introduces a reduction in the sensitivity and noise-equivalent count rate of the PET system and increases the scatter fraction. PET-FOT phantom experiments were performed. An in vivo experiment using both PET and FOT was also performed. CONCLUSION Phantom and in vivo experiments demonstrate the feasibility of simultaneous PET and 3D FOT imaging. The first in vivo simultaneous PET-FOT results are reported.
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Affiliation(s)
- Changqing Li
- Department of Biomedical Engineering, University of California, Davis, Davis, California 95616, USA.
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40
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Correia T, Aguirre J, Sisniega A, Chamorro-Servent J, Abascal J, Vaquero JJ, Desco M, Kolehmainen V, Arridge S. Split operator method for fluorescence diffuse optical tomography using anisotropic diffusion regularisation with prior anatomical information. BIOMEDICAL OPTICS EXPRESS 2011; 2:2632-48. [PMID: 22091447 PMCID: PMC3184872 DOI: 10.1364/boe.2.002632] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 08/14/2011] [Accepted: 08/15/2011] [Indexed: 05/22/2023]
Abstract
Fluorescence diffuse optical tomography (fDOT) is an imaging modality that provides images of the fluorochrome distribution within the object of study. The image reconstruction problem is ill-posed and highly underdetermined and, therefore, regularisation techniques need to be used. In this paper we use a nonlinear anisotropic diffusion regularisation term that incorporates anatomical prior information. We introduce a split operator method that reduces the nonlinear inverse problem to two simpler problems, allowing fast and efficient solution of the fDOT problem. We tested our method using simulated, phantom and ex-vivo mouse data, and found that it provides reconstructions with better spatial localisation and size of fluorochrome inclusions than using the standard Tikhonov penalty term.
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Affiliation(s)
- Teresa Correia
- Department of Computer Science, University College London, Gower Street, London WC1E6BT, UK
| | - Juan Aguirre
- Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid,
Spain
| | - Alejandro Sisniega
- Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid,
Spain
| | - Judit Chamorro-Servent
- Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid,
Spain
| | - Juan Abascal
- Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid,
Spain
| | - Juan J. Vaquero
- Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid,
Spain
| | - Manuel Desco
- Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid,
Spain
- Unidad de Medicina y Cirugía Experimental, Hospital General Universitario Gregorio Marañón, CIBER de Salud Mental (CIBERSAM), Madrid,
Spain
| | - Ville Kolehmainen
- Department of Applied Physics, University of Kuopio, PO BOX 1627, 70211 Kuopio,
Finland
| | - Simon Arridge
- Department of Computer Science, University College London, Gower Street, London WC1E6BT, UK
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41
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Liu X, Liu F, Zhang Y, Bai J. Unmixing dynamic fluorescence diffuse optical tomography images with independent component analysis. IEEE TRANSACTIONS ON MEDICAL IMAGING 2011; 30:1591-604. [PMID: 21632297 DOI: 10.1109/tmi.2011.2134865] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Dynamic fluorescence diffuse optical tomography (D-FDOT) is important for drug delivery research. However, the low spatial resolution of FDOT and the complex kinetics of drug limit the ability of D-FDOT in resolving metabolic processes of drug throughout whole body of small animals. In this paper, we propose an independent component analysis (ICA)-based method to perform D-FDOT studies. When applied to D-FDOT images, ICA not only generates a set of independent components (ICs) which can illustrate functional structures with different kinetic behaviors, but also provides a set of associated time courses (TCs) which can represent normalized time courses of drug in corresponding functional structures. Further, the drug concentration in specific functional structure at different time points can be recovered by an inverse ICA transformation. To evaluate the performance of the proposed algorithm in the study of drug kinetics at whole-body level, simulation study and phantom experiment are both performed on a full-angle FDOT imaging system with line-shaped excitation pattern. In simulation study, the nanoparticle delivery of indocynaine green (ICG) throughout whole body of a digital mouse is simulated and imaged. In phantom experiment, four tubes containing different ICG concentrations are imaged and used to imitate the uptake and excretion of ICG in organs. The results suggest that we can not only illustrate ICG distributions in different functional structures, but also recover ICG concentrations in specific functional structure at different time points, when ICA is applied to D-FDOT images.
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Affiliation(s)
- Xin Liu
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China.
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42
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Lin Y, Ghijsen MT, Gao H, Liu N, Nalcioglu O, Gulsen G. A photo-multiplier tube-based hybrid MRI and frequency domain fluorescence tomography system for small animal imaging. Phys Med Biol 2011; 56:4731-47. [PMID: 21753235 PMCID: PMC3961472 DOI: 10.1088/0031-9155/56/15/007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Fluorescence tomography (FT) is a promising molecular imaging technique that can spatially resolve both fluorophore concentration and lifetime parameters. However, recovered fluorophore parameters highly depend on the size and depth of the object due to the ill-posedness of the FT inverse problem. Structural a priori information from another high spatial resolution imaging modality has been demonstrated to significantly improve FT reconstruction accuracy. In this study, we have constructed a combined magnetic resonance imaging (MRI) and FT system for small animal imaging. A photo-multiplier tube is used as the detector to acquire frequency domain FT measurements. This is the first MR-compatible time-resolved FT system that can reconstruct both fluorescence concentration and lifetime maps simultaneously. The performance of the hybrid system is evaluated with phantom studies. Two different fluorophores, indocyanine green and 3-3' diethylthiatricarbocyanine iodide, which have similar excitation and emission spectra but different lifetimes, are utilized. The fluorescence concentration and lifetime maps are both reconstructed with and without the structural a priori information obtained from MRI for comparison. We show that the hybrid system can accurately recover both fluorescence intensity and lifetime within 10% error for two 4.2 mm-diameter cylindrical objects embedded in a 38 mm-diameter cylindrical phantom when MRI structural a priori information is utilized.
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Affiliation(s)
- Y Lin
- Tu and Yuen Center for Functional Onco Imaging, University of California, Irvine, CA, 92697, USA
| | - M T Ghijsen
- Tu and Yuen Center for Functional Onco Imaging, University of California, Irvine, CA, 92697, USA
| | - H Gao
- Department of Mathematics, University of California, Los Angeles, CA 90095, USA
| | - N Liu
- Tu and Yuen Center for Functional Onco Imaging, University of California, Irvine, CA, 92697, USA
| | - O Nalcioglu
- Tu and Yuen Center for Functional Onco Imaging, University of California, Irvine, CA, 92697, USA
- Department of Cogno-Mechatronics Engineering, Pusan National University, Pusan, Korea
| | - G Gulsen
- Tu and Yuen Center for Functional Onco Imaging, University of California, Irvine, CA, 92697, USA
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Xin Liu, Xiaolian Guo, Fei Liu, Yi Zhang, Hui Zhang, Guangshu Hu, Jing Bai. Imaging of Indocyanine Green Perfusion in Mouse Liver With Fluorescence Diffuse Optical Tomography. IEEE Trans Biomed Eng 2011. [DOI: 10.1109/tbme.2011.2135858] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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44
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Fluorescence molecular tomography: principles and potential for pharmaceutical research. Pharmaceutics 2011; 3:229-74. [PMID: 24310495 PMCID: PMC3864234 DOI: 10.3390/pharmaceutics3020229] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2011] [Revised: 04/07/2011] [Accepted: 04/15/2011] [Indexed: 11/17/2022] Open
Abstract
Fluorescence microscopic imaging is widely used in biomedical research to study molecular and cellular processes in cell culture or tissue samples. This is motivated by the high inherent sensitivity of fluorescence techniques, the spatial resolution that compares favorably with cellular dimensions, the stability of the fluorescent labels used and the sophisticated labeling strategies that have been developed for selectively labeling target molecules. More recently, two and three-dimensional optical imaging methods have also been applied to monitor biological processes in intact biological organisms such as animals or even humans. These whole body optical imaging approaches have to cope with the fact that biological tissue is a highly scattering and absorbing medium. As a consequence, light propagation in tissue is well described by a diffusion approximation and accurate reconstruction of spatial information is demanding. While in vivo optical imaging is a highly sensitive method, the signal is strongly surface weighted, i.e., the signal detected from the same light source will become weaker the deeper it is embedded in tissue, and strongly depends on the optical properties of the surrounding tissue. Derivation of quantitative information, therefore, requires tomographic techniques such as fluorescence molecular tomography (FMT), which maps the three-dimensional distribution of a fluorescent probe or protein concentration. The combination of FMT with a structural imaging method such as X-ray computed tomography (CT) or Magnetic Resonance Imaging (MRI) will allow mapping molecular information on a high definition anatomical reference and enable the use of prior information on tissue's optical properties to enhance both resolution and sensitivity. Today many of the fluorescent assays originally developed for studies in cellular systems have been successfully translated for experimental studies in animals. The opportunity of monitoring molecular processes non-invasively in the intact organism is highly attractive from a diagnostic point of view but even more so for the drug developer, who can use the techniques for proof-of-mechanism and proof-of-efficacy studies. This review shall elucidate the current status and potential of fluorescence tomography including recent advances in multimodality imaging approaches for preclinical and clinical drug development.
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Ripoll J, Ntziachristos V. Light, sound, chemistry… action: state of the art optical methods for animal imaging. DRUG DISCOVERY TODAY. TECHNOLOGIES 2011; 8:e79-e86. [PMID: 24990266 DOI: 10.1016/j.ddtec.2011.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
During recent years, macroscopic optical methods have been promoted from backstage to main actors in biological imaging. Many possible forms of energy conservation have been explored that involve light, including fluorescence emission, sound generated through absorption and bioluminescence, that is light generated through a chemical reaction. These physicochemical approaches for contrast generation have resulted in optical imaging methods that come with potent performance characteristics over simple epi-illumination optical imaging approaches of the past, and can play a central role in imaging applications in vivo as it pertains to modern biological and drug discovery, pre-clinical imaging and clinical applications. This review focuses on state of the art optical and opto-acoustic (photo-acoustic) imaging methods and discusses key performance characteristics that convert optical imaging from a qualitative modality to a powerful high-resolution and quantitative volumetric interrogation tool for operation through several millimeters of tissue depth.:
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Affiliation(s)
- Jorge Ripoll
- Institute for Electronic Structure and Laser, Foundation for Research and Technology-Hellas, Nikolaos Plastira 100, 7110 Heraklion, Greece.
| | - Vasilis Ntziachristos
- Institute for Biological and Medical Imaging, Helmholtz Zentrum München, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
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Naser MA, Patterson MS. Improved bioluminescence and fluorescence reconstruction algorithms using diffuse optical tomography, normalized data, and optimized selection of the permissible source region. BIOMEDICAL OPTICS EXPRESS 2010; 2:169-184. [PMID: 21326647 PMCID: PMC3028492 DOI: 10.1364/boe.2.000169] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Revised: 12/16/2010] [Accepted: 12/17/2010] [Indexed: 05/29/2023]
Abstract
Reconstruction algorithms are presented for two-step solutions of the bioluminescence tomography (BLT) and the fluorescence tomography (FT) problems. In the first step, a continuous wave (cw) diffuse optical tomography (DOT) algorithm is used to reconstruct the tissue optical properties assuming known anatomical information provided by x-ray computed tomography or other methods. Minimization problems are formed based on L1 norm objective functions, where normalized values for the light fluence rates and the corresponding Green's functions are used. Then an iterative minimization solution shrinks the permissible regions where the sources are allowed by selecting points with higher probability to contribute to the source distribution. Throughout this process the permissible region shrinks from the entire object to just a few points. The optimum reconstructed bioluminescence and fluorescence distributions are chosen to be the results of the iteration corresponding to the permissible region where the objective function has its global minimum This provides efficient BLT and FT reconstruction algorithms without the need for a priori information about the bioluminescence sources or the fluorophore concentration. Multiple small sources and large distributed sources can be reconstructed with good accuracy for the location and the total source power for BLT and the total number of fluorophore molecules for the FT. For non-uniform distributed sources, the size and magnitude become degenerate due to the degrees of freedom available for possible solutions. However, increasing the number of data points by increasing the number of excitation sources can improve the accuracy of reconstruction for non-uniform fluorophore distributions.
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Affiliation(s)
- Mohamed A. Naser
- Department of Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S4K1, Canada
| | - Michael S. Patterson
- Department of Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S4K1, Canada
- Juravinski Cancer Center, 699 Concession Street, Hamilton, Ontario L8V5C2, Canada
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47
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Radiologic and near-infrared/optical spectroscopic imaging: where is the synergy? AJR Am J Roentgenol 2010; 195:321-32. [PMID: 20651186 DOI: 10.2214/ajr.10.5002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Optical and radiologic imaging are commonly used in preclinical research, and research into combined instruments for human applications is showing promise. The purpose of this article is to outline the fundamental limitations and advantages and to review the available systems. The emerging developments and future potential will be summarized. CONCLUSION Integration of hybrid systems is now routine at the preclinical level and appears in the form of specialized packages in which performance varies considerably. The synergy is commonly focused on using spatial localization from radiographs to provide structural data for spectroscopy; however, applications also exist in which the spectroscopy informs the use of radiologic imaging. Examples of clinical systems under research and development are shown.
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Guo X, Liu X, Wang X, Tian F, Liu F, Zhang B, Hu G, Bai J. A combined fluorescence and microcomputed tomography system for small animal imaging. IEEE Trans Biomed Eng 2010; 57:2876-83. [PMID: 20833597 DOI: 10.1109/tbme.2010.2073468] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Fluorescence molecular tomography (FMT) plays an important role in studying physiological and pathological processes of small animals in vivo at molecular level. However, this technique suffers from relatively low spatial resolution. To complement the problem, there has been a strong demand for providing functional and morphological analysis at the same time. In this paper, we proposed a hybrid full-angle free-space FMT and X-ray micro-cone-beam computed tomography (CT) (micro-CBCT) prototype system, providing both functional and anatomical images. During the whole acquisition, the two subsystems acquire projection images (fluorescence and CT) synchronously to keep consistent body position without moving the animals. The acquired datasets are intrinsically coregistered in the corresponding coordinate and identified geometry. Tomographic fluorescence and CT images are reconstructed using normalized Born-based spatial regularization and Feldkamp-Davis-Kress methods, respectively. The experimental results of both phantom and in vivo mouse preliminarily validate the accuracy and performance of the integrated system.
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Affiliation(s)
- Xiaolian Guo
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China.
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