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Kim SJ, Lee HY. In vivo molecular imaging in preclinical research. Lab Anim Res 2022; 38:31. [PMID: 36266669 PMCID: PMC9585739 DOI: 10.1186/s42826-022-00142-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 09/15/2022] [Accepted: 09/20/2022] [Indexed: 11/19/2022] Open
Abstract
In vivo molecular imaging is a research field in which molecular biology and advanced imaging techniques are combined for imaging molecular-level biochemical and physiological changes that occur in a living body. For biomolecular imaging, the knowledge of molecular biology, cell biology, biochemistry, and physiology must be applied. Imaging techniques such as fluorescence, luminescence, single-photon emission computed tomography (SPECT), positron emission tomography (PET), computed tomography (CT), and magnetic resonance imaging (MRI) are used for biomolecular imaging. These imaging techniques are used in various fields, i.e., diagnosis of various diseases, development of new drugs, development of treatments, and evaluation of effects. Moreover, as biomolecular imaging can repeatedly acquire images without damaging biological tissues or sacrificing the integrity of objects, changes over time can be evaluated. Phenotypes or diseases in a living body are caused by the accumulation of various biological phenomena. Genetic differences cause biochemical and physiological differences, which accumulate and cause anatomical or structural changes. Biomolecular imaging techniques are suitable for each step. In evaluating anatomical or structural changes, MRI, CT, and ultrasound have advantages in obtaining high-resolution images. SPECT and MRI are advantageous for the evaluation of various physiological phenomena. PET and magnetic resonance spectroscopy can be used to image biochemical phenomena in vivo. Although various biomolecular imaging techniques can be used to evaluate various biological phenomena, it is important to use imaging techniques suitable for each purpose.
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Affiliation(s)
- Su Jin Kim
- Department of Nuclear Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Ho-Young Lee
- Department of Nuclear Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea. .,Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, South Korea.
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2
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Bao B, Vasquez KO, Ho G, Zhang J, Delaney J, Rajopadhye M, Peterson JD. Blood Pharmacokinetics Imaging by Noninvasive Heart Fluorescence Tomography and Application to Kidney Glomerular Filtration Rate Assessment. J Pharmacol Exp Ther 2019; 370:288-298. [DOI: 10.1124/jpet.119.257071] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 05/24/2019] [Indexed: 02/04/2023] Open
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3
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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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4
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Favicchio R, Psycharakis S, Schönig K, Bartsch D, Mamalaki C, Papamatheakis J, Ripoll J, Zacharakis G. Quantitative performance characterization of three-dimensional noncontact fluorescence molecular tomography. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:26009. [PMID: 26891600 DOI: 10.1117/1.jbo.21.2.026009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 01/13/2016] [Indexed: 05/23/2023]
Abstract
Fluorescent proteins and dyes are routine tools for biological research to describe the behavior of genes, proteins, and cells, as well as more complex physiological dynamics such as vessel permeability and pharmacokinetics. The use of these probes in whole body in vivo imaging would allow extending the range and scope of current biomedical applications and would be of great interest. In order to comply with a wide variety of application demands, in vivo imaging platform requirements span from wide spectral coverage to precise quantification capabilities. Fluorescence molecular tomography (FMT) detects and reconstructs in three dimensions the distribution of a fluorophore in vivo. Noncontact FMT allows fast scanning of an excitation source and noninvasive measurement of emitted fluorescent light using a virtual array detector operating in free space. Here, a rigorous process is defined that fully characterizes the performance of a custom-built horizontal noncontact FMT setup. Dynamic range, sensitivity, and quantitative accuracy across the visible spectrum were evaluated using fluorophores with emissions between 520 and 660 nm. These results demonstrate that high-performance quantitative three-dimensional visible light FMT allowed the detection of challenging mesenteric lymph nodes in vivo and the comparison of spectrally distinct fluorescent reporters in cell culture.
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Affiliation(s)
- Rosy Favicchio
- Imperial College London, Hammersmith Hospital, Department of Surgery and Cancer, Division of Cancer, Du Cane Road, London W12 0NN, United KingdombFoundation for Research and Technology Hellas-Institute of Electronic Structure and Laser, N. Plastira 100, 7
| | - Stylianos Psycharakis
- Foundation for Research and Technology Hellas-Institute of Electronic Structure and Laser, N. Plastira 100, 7100 Heraklion, Crete, Greece
| | - Kai Schönig
- Central Institute of Mental Health and Heidelberg University, Department of Molecular Biology, Medical Faculty Mannheim, J5, 68159 Mannheim, Germany
| | - Dusan Bartsch
- Central Institute of Mental Health and Heidelberg University, Department of Molecular Biology, Medical Faculty Mannheim, J5, 68159 Mannheim, Germany
| | - Clio Mamalaki
- Foundation for Research and Technology Hellas-Institute of Molecular Biology and Biotechnology, N. Plastira 100, 7100 Heraklion, Crete, Greece
| | - Joseph Papamatheakis
- Foundation for Research and Technology Hellas-Institute of Molecular Biology and Biotechnology, N. Plastira 100, 7100 Heraklion, Crete, Greece
| | - Jorge Ripoll
- Universidad Carlos III of Madrid, Department of Bioengineering and Aerospace Engineering, 28911 Madrid, SpainfInstituto de Investigación Sanitaria del Hospital Gregorio Marañón, Experimental Medicine and Surgery Unit, 28007 Madrid, Spain
| | - Giannis Zacharakis
- Foundation for Research and Technology Hellas-Institute of Electronic Structure and Laser, N. Plastira 100, 7100 Heraklion, Crete, Greece
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5
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Wang D, He J, Qiao H, Li P, Fan Y, Li D. Noncontact full-angle fluorescence molecular tomography system based on rotary mirrors. APPLIED OPTICS 2015; 54:7062-70. [PMID: 26368376 DOI: 10.1364/ao.54.007062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We propose a novel noncontact fluorescence molecular tomography system that achieves full-angle capacity with the use of a new rotary-mirrors-based imaging head. In the imaging head, four plane mirrors are mounted on a rotating gantry to enable illumination and detection over 360°. In comparison with existing full-angle systems, our system does not require rotation of the specimen animal, a large and heavy light source (with scanning head), or a bulky camera (with filters and lens). The system design and implementation are described in detail. Both physical phantom and in vivo experiments are performed to verify the performance of the proposed system.
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6
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Darne C, Lu Y, Sevick-Muraca EM. Small animal fluorescence and bioluminescence tomography: a review of approaches, algorithms and technology update. Phys Med Biol 2013; 59:R1-64. [PMID: 24334634 DOI: 10.1088/0031-9155/59/1/r1] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Emerging fluorescence and bioluminescence tomography approaches have several common, yet several distinct features from established emission tomographies of PET and SPECT. Although both nuclear and optical imaging modalities involve counting of photons, nuclear imaging techniques collect the emitted high energy (100-511 keV) photons after radioactive decay of radionuclides while optical techniques count low-energy (1.5-4.1 eV) photons that are scattered and absorbed by tissues requiring models of light transport for quantitative image reconstruction. Fluorescence imaging has been recently translated into clinic demonstrating high sensitivity, modest tissue penetration depth, and fast, millisecond image acquisition times. As a consequence, the promise of quantitative optical tomography as a complement of small animal PET and SPECT remains high. In this review, we summarize the different instrumentation, methodological approaches and schema for inverse image reconstructions for optical tomography, including luminescence and fluorescence modalities, and comment on limitations and key technological advances needed for further discovery research and translation.
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7
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Byrne WL, DeLille A, Kuo C, de Jong JS, van Dam GM, Francis KP, Tangney M. Use of optical imaging to progress novel therapeutics to the clinic. J Control Release 2013; 172:523-34. [PMID: 23680286 DOI: 10.1016/j.jconrel.2013.05.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Revised: 04/30/2013] [Accepted: 05/06/2013] [Indexed: 01/02/2023]
Abstract
There is an undisputed need for employment and improvement of robust technology for real-time analyses of therapeutic delivery and responses in clinical translation of gene and cell therapies. Over the past decade, optical imaging has become the in vivo imaging modality of choice for many preclinical laboratories due to its efficiency, practicality and affordability, while more recently, the clinical potential for this technology is becoming apparent. This review provides an update on the current state of the art in in vivo optical imaging and discusses this rapidly improving technology in the context of it representing a translation enabler or indeed a future clinical imaging modality in its own right.
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Affiliation(s)
- William L Byrne
- Cork Cancer Research Centre, BioScience Institute, University College Cork, Cork, Ireland
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8
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Ren S, Chen X, Wang H, Qu X, Wang G, Liang J, Tian J. Molecular Optical Simulation Environment (MOSE): a platform for the simulation of light propagation in turbid media. PLoS One 2013; 8:e61304. [PMID: 23577215 PMCID: PMC3620115 DOI: 10.1371/journal.pone.0061304] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 03/06/2013] [Indexed: 01/28/2023] Open
Abstract
The study of light propagation in turbid media has attracted extensive attention in the field of biomedical optical molecular imaging. In this paper, we present a software platform for the simulation of light propagation in turbid media named the “Molecular Optical Simulation Environment (MOSE)”. Based on the gold standard of the Monte Carlo method, MOSE simulates light propagation both in tissues with complicated structures and through free-space. In particular, MOSE synthesizes realistic data for bioluminescence tomography (BLT), fluorescence molecular tomography (FMT), and diffuse optical tomography (DOT). The user-friendly interface and powerful visualization tools facilitate data analysis and system evaluation. As a major measure for resource sharing and reproducible research, MOSE aims to provide freeware for research and educational institutions, which can be downloaded at http://www.mosetm.net.
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Affiliation(s)
- Shenghan Ren
- School of Life Sciences and Technology, Xidian University, Xi’an, Shaanxi, China
| | - Xueli Chen
- School of Life Sciences and Technology, Xidian University, Xi’an, Shaanxi, China
| | - Hailong Wang
- School of Life Sciences and Technology, Xidian University, Xi’an, Shaanxi, China
| | - Xiaochao Qu
- School of Life Sciences and Technology, Xidian University, Xi’an, Shaanxi, China
| | - Ge Wang
- Biomedical Imaging Center, Rensselaer Polytechnic Institute, Troy, New York, United States of America
- * E-mail: (GW); (JL); (JT)
| | - Jimin Liang
- School of Life Sciences and Technology, Xidian University, Xi’an, Shaanxi, China
- * E-mail: (GW); (JL); (JT)
| | - Jie Tian
- School of Life Sciences and Technology, Xidian University, Xi’an, Shaanxi, China
- Institute of Automation, Chinese Academy of Sciences, Beijing, China
- * E-mail: (GW); (JL); (JT)
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9
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Basevi HRA, Guggenheim JA, Dehghani H, Styles IB. Simultaneous multiple view high resolution surface geometry acquisition using structured light and mirrors. OPTICS EXPRESS 2013; 21:7222-39. [PMID: 23546107 DOI: 10.1364/oe.21.007222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Knowledge of the surface geometry of an imaging subject is important in many applications. This information can be obtained via a number of different techniques, including time of flight imaging, photogrammetry, and fringe projection profilometry. Existing systems may have restrictions on instrument geometry, require expensive optics, or require moving parts in order to image the full surface of the subject. An inexpensive generalised fringe projection profilometry system is proposed that can account for arbitrarily placed components and use mirrors to expand the field of view. It simultaneously acquires multiple views of an imaging subject, producing a cloud of points that lie on its surface, which can then be processed to form a three dimensional model. A prototype of this system was integrated into an existing Diffuse Optical Tomography and Bioluminescence Tomography small animal imaging system and used to image objects including a mouse-shaped plastic phantom, a mouse cadaver, and a coin. A surface mesh generated from surface capture data of the mouse-shaped plastic phantom was compared with ideal surface points provided by the phantom manufacturer, and 50% of points were found to lie within 0.1mm of the surface mesh, 82% of points were found to lie within 0.2mm of the surface mesh, and 96% of points were found to lie within 0.4mm of the surface mesh.
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Affiliation(s)
- Hector R A Basevi
- PSIBS, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom.
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10
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A hybrid reconstruction algorithm for fluorescence tomography using Kirchhoff approximation and finite element method. Med Biol Eng Comput 2012. [DOI: 10.1007/s11517-012-0953-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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11
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Heidrich M, Kühnel MP, Kellner M, Lorbeer RA, Lange T, Winkel A, Stiesch M, Meyer H, Heisterkamp A. 3D imaging of biofilms on implants by detection of scattered light with a scanning laser optical tomograph. BIOMEDICAL OPTICS EXPRESS 2011; 2:2982-94. [PMID: 22076261 PMCID: PMC3207369 DOI: 10.1364/boe.2.002982] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 09/02/2011] [Accepted: 09/02/2011] [Indexed: 05/13/2023]
Abstract
Biofilms - communities of microorganisms attached to surfaces - are a constant threat for long-term success in modern implantology. The application of laser scanning microscopy (LSM) has increased the knowledge about microscopic properties of biofilms, whereas a 3D imaging technique for the large scale visualization of bacterial growth and migration on curved and non-transparent surfaces is not realized so far.Towards this goal, we built a scanning laser optical tomography (SLOT) setup detecting scattered laser light to image biofilm on dental implant surfaces. SLOT enables the visualization of living biofilms in 3D by detecting the wavelength-dependent absorption of non-fluorescent stains like e.g. reduced triphenyltetrazolium chloride (TTC) accumulated within metabolically active bacterial cells. Thus, the presented system allows the large scale investigation of vital biofilm structure and in vitro development on cylindrical and non-transparent objects without the need for fluorescent vital staining. We suggest SLOT to be a valuable tool for the structural and volumetric investigation of biofilm formation on implants with sizes up to several millimeters.
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Affiliation(s)
- Marko Heidrich
- Biomedical Optics Department, Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hannover,
Germany
- Institute of Quantum Optics, Gottfried Wilhelm Leibniz Universität Hannover, Welfengarten1, D-30167 Hannover,
Germany
| | - Mark P. Kühnel
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, Carl-Neubergstr.1, D-30625 Hannover,
Germany
| | - Manuela Kellner
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, Carl-Neubergstr.1, D-30625 Hannover,
Germany
| | - Raoul-Amadeus Lorbeer
- Biomedical Optics Department, Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hannover,
Germany
| | - Tineke Lange
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, Carl-Neubergstr.1, D-30625 Hannover,
Germany
| | - Andreas Winkel
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, Carl-Neubergstr.1, D-30625 Hannover,
Germany
- CrossBIT Verbundzentrum für Biokompatibilität und Implantatimmunologie in der Medizintechnik, Feodor-Lynen-Straße 31, D-30625 Hannover,
Germany
| | - Meike Stiesch
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, Carl-Neubergstr.1, D-30625 Hannover,
Germany
| | - Heiko Meyer
- Biomedical Optics Department, Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hannover,
Germany
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neubergstr.1, D-30625 Hannover,
Germany
| | - Alexander Heisterkamp
- Biomedical Optics Department, Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hannover,
Germany
- Institute of Quantum Optics, Gottfried Wilhelm Leibniz Universität Hannover, Welfengarten1, D-30167 Hannover,
Germany
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12
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Gioux S, Mazhar A, Lee BT, Lin SJ, Tobias AM, Cuccia DJ, Stockdale A, Oketokoun R, Ashitate Y, Kelly E, Weinmann M, Durr NJ, Moffitt LA, Durkin AJ, Tromberg BJ, Frangioni JV. First-in-human pilot study of a spatial frequency domain oxygenation imaging system. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:086015. [PMID: 21895327 PMCID: PMC3182084 DOI: 10.1117/1.3614566] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 06/30/2011] [Accepted: 07/01/2011] [Indexed: 05/18/2023]
Abstract
Oxygenation measurements are widely used in patient care. However, most clinically available instruments currently consist of contact probes that only provide global monitoring of the patient (e.g., pulse oximetry probes) or local monitoring of small areas (e.g., spectroscopy-based probes). Visualization of oxygenation over large areas of tissue, without a priori knowledge of the location of defects, has the potential to improve patient management in many surgical and critical care applications. In this study, we present a clinically compatible multispectral spatial frequency domain imaging (SFDI) system optimized for surgical oxygenation imaging. This system was used to image tissue oxygenation over a large area (16×12 cm) and was validated during preclinical studies by comparing results obtained with an FDA-approved clinical oxygenation probe. Skin flap, bowel, and liver vascular occlusion experiments were performed on Yorkshire pigs and demonstrated that over the course of the experiment, relative changes in oxygen saturation measured using SFDI had an accuracy within 10% of those made using the FDA-approved device. Finally, the new SFDI system was translated to the clinic in a first-in-human pilot study that imaged skin flap oxygenation during reconstructive breast surgery. Overall, this study lays the foundation for clinical translation of endogenous contrast imaging using SFDI.
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Affiliation(s)
- Sylvain Gioux
- Beth Israel Deaconess Medical Center, Division of Hematology∕Oncology, Department of Medicine, Boston, Massachusetts 02215, USA
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13
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Goergen CJ, Sosnovik DE. From molecules to myofibers: multiscale imaging of the myocardium. J Cardiovasc Transl Res 2011; 4:493-503. [PMID: 21643889 DOI: 10.1007/s12265-011-9284-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 04/26/2011] [Indexed: 01/14/2023]
Abstract
Pathology in the heart can be examined at several scales, ranging from the molecular to the macroscopic. Traditionally, fluorescence-based techniques such as flow cytometry have been used to study the myocardium at the molecular, cellular, and microscopic levels. Recent advances in magnetic resonance imaging (MRI), however, have made it possible to image certain cellular and molecular events in the myocardium noninvasively in vivo. In addition, diffusion MRI has been used to image myocardial fiber architecture and microstructure in the intact heart. Diffusion MRI tractography, in particular, is providing novel insights into myocardial microsctructure in both health and disease. Recent developments have also been made in fluorescence imaging, making it possible to image fluorescent probes in the heart of small animals noninvasively in vivo. Moreover, techniques have been developed to perform in vivo fluorescence tomography of the mouse heart. These advances in MRI and fluorescence imaging allow events in the myocardium to be imaged at several scales linking molecular changes to alterations in microstructure and microstructural changes to gross function. A complete and integrated picture of pathophysiology in the myocardium is thus obtained. This multiscale approach has the potential to be of significant value not only in preclinical research but, ultimately, in the clinical arena as well.
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Affiliation(s)
- Craig J Goergen
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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14
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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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15
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Chen X, Gao X, Qu X, Chen D, Ma X, Liang J, Tian J. Generalized free-space diffuse photon transport model based on the influence analysis of a camera lens diaphragm. APPLIED OPTICS 2010; 49:5654-5664. [PMID: 20935713 DOI: 10.1364/ao.49.005654] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The camera lens diaphragm is an important component in a noncontact optical imaging system and has a crucial influence on the images registered on the CCD camera. However, this influence has not been taken into account in the existing free-space photon transport models. To model the photon transport process more accurately, a generalized free-space photon transport model is proposed. It combines Lambertian source theory with analysis of the influence of the camera lens diaphragm to simulate photon transport process in free space. In addition, the radiance theorem is also adopted to establish the energy relationship between the virtual detector and the CCD camera. The accuracy and feasibility of the proposed model is validated with a Monte-Carlo-based free-space photon transport model and physical phantom experiment. A comparison study with our previous hybrid radiosity-radiance theorem based model demonstrates the improvement performance and potential of the proposed model for simulating photon transport process in free space.
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Affiliation(s)
- Xueli Chen
- Video and Image Processing System Laboratory, School of Electronic Engineering, Xidian University, Xi’an, Shaanxi 710071, China
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16
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Joshi AA, Chaudhari AJ, Li C, Dutta J, Cherry SR, Shattuck DW, Toga AW, Leahy RM. DigiWarp: a method for deformable mouse atlas warping to surface topographic data. Phys Med Biol 2010; 55:6197-214. [PMID: 20885019 DOI: 10.1088/0031-9155/55/20/011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
For pre-clinical bioluminescence or fluorescence optical tomography, the animal's surface topography and internal anatomy need to be estimated for improving the quantitative accuracy of reconstructed images. The animal's surface profile can be measured by all-optical systems, but estimation of the internal anatomy using optical techniques is non-trivial. A 3D anatomical mouse atlas may be warped to the estimated surface. However, fitting an atlas to surface topography data is challenging because of variations in the posture and morphology of imaged mice. In addition, acquisition of partial data (for example, from limited views or with limited sampling) can make the warping problem ill-conditioned. Here, we present a method for fitting a deformable mouse atlas to surface topographic range data acquired by an optical system. As an initialization procedure, we match the posture of the atlas to the posture of the mouse being imaged using landmark constraints. The asymmetric L(2) pseudo-distance between the atlas surface and the mouse surface is then minimized in order to register two data sets. A Laplacian prior is used to ensure smoothness of the surface warping field. Once the atlas surface is normalized to match the range data, the internal anatomy is transformed using elastic energy minimization. We present results from performance evaluation studies of our method where we have measured the volumetric overlap between the internal organs delineated directly from MRI or CT and those estimated by our proposed warping scheme. Computed Dice coefficients indicate excellent overlap in the brain and the heart, with fair agreement in the kidneys and the bladder.
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Affiliation(s)
- Anand A Joshi
- Laboratory of Neuro Imaging, UCLA School of Medicine, Los Angeles, CA 90095, USA.
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17
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Chen X, Gao X, Chen D, Ma X, Zhao X, Shen M, Li X, Qu X, Liang J, Ripoll J, Tian J. 3D reconstruction of light flux distribution on arbitrary surfaces from 2D multi-photographic images. OPTICS EXPRESS 2010; 18:19876-93. [PMID: 20940879 DOI: 10.1364/oe.18.019876] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Optical tomography can demonstrate accurate three-dimensional (3D) imaging that recovers the 3D spatial distribution and concentration of the luminescent probes in biological tissues, compared with planar imaging. However, the tomographic approach is extremely difficult to implement due to the complexity in the reconstruction of 3D surface flux distribution from multi-view two dimensional (2D) measurements on the subject surface. To handle this problem, a novel and effective method is proposed in this paper to determine the surface flux distribution from multi-view 2D photographic images acquired by a set of non-contact detectors. The method is validated with comparison experiments involving both regular and irregular surfaces. Reconstruction of the inside probes based on the reconstructed surface flux distribution further demonstrates the potential of the proposed method in its application in optical tomography.
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Affiliation(s)
- Xueli Chen
- Life Sciences Research Center, School of Life Sciences and Technology, Xidian University, Xi'an, Shaanxi, China
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18
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Ale A, Schulz RB, Sarantopoulos A, Ntziachristos V. Imaging performance of a hybrid x-ray computed tomography-fluorescence molecular tomography system using priors. Med Phys 2010; 37:1976-86. [PMID: 20527531 DOI: 10.1118/1.3368603] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The performance is studied of two newly introduced and previously suggested methods that incorporate priors into inversion schemes associated with data from a recently developed hybrid x-ray computed tomography and fluorescence molecular tomography system, the latter based on CCD camera photon detection. The unique data set studied attains accurately registered data of high spatially sampled photon fields propagating through tissue along 360 degrees projections. METHODS Approaches that incorporate structural prior information were included in the inverse problem by adding a penalty term to the minimization function utilized for image reconstructions. Results were compared as to their performance with simulated and experimental data from a lung inflammation animal model and against the inversions achieved when not using priors. RESULTS The importance of using priors over stand-alone inversions is also showcased with high spatial sampling simulated and experimental data. The approach of optimal performance in resolving fluorescent biodistribution in small animals is also discussed. CONCLUSIONS Inclusion of prior information from x-ray CT data in the reconstruction of the fluorescence biodistribution leads to improved agreement between the reconstruction and validation images for both simulated and experimental data.
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Affiliation(s)
- Angelique Ale
- Institute for Biological and Medical Imaging, Technische Universität München and Helmholtz Zentrum München, Ingolstädter Landstrasse 1, D-85764 Neuherberg, Germany
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19
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A parallel excitation based fluorescence molecular tomography system for whole-body simultaneous imaging of small animals. Ann Biomed Eng 2010; 38:3440-8. [PMID: 20544284 DOI: 10.1007/s10439-010-0093-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 05/30/2010] [Indexed: 10/19/2022]
Abstract
Challenges remain in imaging complete dynamic physiological processes in vivo through the whole small animal body using fluorescence molecular tomography (FMT). In this article, a novel non-contact full-angle FMT system that enables whole-body simultaneous imaging of small animals is presented. The whole-body simultaneous imaging ability is achieved by employing a line-shaped parallel excitation source, which can provide extended spatial sampling dataset to reconstruct multiple fluorescent targets distributed in whole animal body during one full-angle FMT imaging process. The key performances of this system were evaluated by a series of experiments. Quantitation linearity for over two orders of magnitude of fluorescence markers concentration was demonstrated, and an accessible simultaneous imaging domain of 4.0 x 1.5 cm² could be achieved utilizing the parallel excitation pattern. Moreover, the in vivo imaging feasibility and performance were validated by localizing two fluorescent targets implanted at different positions of a nude mouse. The results suggest that compared with conventional single point excitation FMT system, the proposed system can achieve a whole-body simultaneous imaging domain and impart the ability to image complete dynamic physiological processes in vivo.
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20
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Liu X, Wang D, Bai J. Fluorescence molecular tomography with optimal radon transform based surface reconstruction. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2010; 2009:1404-7. [PMID: 19964524 DOI: 10.1109/iembs.2009.5334178] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Full angle non-contact fluorescence molecular tomography allows acquiring large data sets from complete angles, and simplifies the experimental setups. Accurately extracting animal surface is important for this kind of imaging systems. However, in in-vivo experiments, mouse breath movements and mechanical errors will influence the surface reconstruction. An optimal radon transform based surface reconstruction method is proposed to handle these two factors. The proposed method uses a line searching method to minimize the mismatch between the reconstructed 3D surface and the projected silhouettes at different angles. Therefore, the proposed method generates the optimal 3D surface compared to other methods based on radon transform. Results show that the mean mismatch of 3D surface generated is less than two CCD pixels (0.154 mm) in in-vivo experiments. In-vivo fluorescence molecular tomography is also performed to demonstrate the efficiency of the proposed method.
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Affiliation(s)
- Xin Liu
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
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21
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Liu X, Wang D, Liu F, Bai J. Principal component analysis of dynamic fluorescence diffuse optical tomography images. OPTICS EXPRESS 2010; 18:6300-14. [PMID: 20389653 DOI: 10.1364/oe.18.006300] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Challenges remain in resolving drug distributions within small animals utilizing fluorescence diffuse optical tomography (FDOT). In this paper, we present a new method for detecting and visualizing organs with different kinetics utilizing principal component analysis (PCA). Indocynaine green (ICG) metabolic processes are simulated and imaged using FDOT. When applied to the time series of generated FDOT images, PCA provides a set of the principal components (PCs) which can represent spatial patterns associated with different kinetic behavior. Simulation and experiment studies are both performed to validate the performance of the proposed algorithm. The results suggest that we are able to extract and illustrate changes in ICG kinetic behavior between the heart and the lungs.
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Affiliation(s)
- Xin Liu
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
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22
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Kepshire DL, Dehghani H, Leblond F, Pogue BW. Automatic exposure control and estimation of effective system noise in diffuse fluorescence tomography. OPTICS EXPRESS 2009; 17:23272-83. [PMID: 20052253 PMCID: PMC3784615 DOI: 10.1364/oe.17.023272] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
A diffuse fluorescence tomography system, based upon time-correlated single photon counting, is presented with an automated algorithm to allow dynamic range variation through exposure control. This automated exposure control allows the upper and lower detection levels of fluorophore to be extended by an order of magnitude beyond the previously published performance and benefits in a slight decrease in system effective noise. The effective noise level is used as a metric to characterize the system performance, integrating both model-mismatch and calibration bias errors into a single parameter. This effective error is near 7% of the reconstructed fluorescent yield value, when imaging in just few minutes. Quantifying protoporphyrin IX concentrations down to 50 ng/ml is possible, for tumor-sized regions. This fluorophore has very low fluorescence yield, but high biological relevance for tumor imaging, given that it is produced in the mitochondria, and upregulated in many tumor types.
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Affiliation(s)
- Dax L. Kepshire
- Thayer School of Engineering, Dartmouth College, 8000 Cummings Hall, Hanover N.H. 03755, USA
| | - Hamid Dehghani
- Thayer School of Engineering, Dartmouth College, 8000 Cummings Hall, Hanover N.H. 03755, USA
- School of Computer Science, University of Birmingham, Birmingham B15 2TT, UK
| | - Frederic Leblond
- Thayer School of Engineering, Dartmouth College, 8000 Cummings Hall, Hanover N.H. 03755, USA
| | - Brian W. Pogue
- Thayer School of Engineering, Dartmouth College, 8000 Cummings Hall, Hanover N.H. 03755, USA
- Department of Surgery, Dartmouth Medical School, Lebanon N.H. 03756, USA
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23
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Raymond SB, Kumar ATN, Boas DA, Bacskai BJ. Optimal parameters for near infrared fluorescence imaging of amyloid plaques in Alzheimer's disease mouse models. Phys Med Biol 2009; 54:6201-16. [PMID: 19794239 DOI: 10.1088/0031-9155/54/20/011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Amyloid-beta plaques are an Alzheimer's disease biomarker which present unique challenges for near-infrared fluorescence tomography because of size (<50 microm diameter) and distribution. We used high-resolution simulations of fluorescence in a digital Alzheimer's disease mouse model to investigate the optimal fluorophore and imaging parameters for near-infrared fluorescence tomography of amyloid plaques. Fluorescence was simulated for amyloid-targeted probes with emission at 630 and 800 nm, plaque-to-background ratios from 1-1000, amyloid burden from 0-10%, and for transmission and reflection measurement geometries. Fluorophores with high plaque-to-background contrast ratios and 800 nm emission performed significantly better than current amyloid imaging probes. We tested idealized fluorophores in transmission and full-angle tomographic measurement schemes (900 source-detector pairs), with and without anatomical priors. Transmission reconstructions demonstrated strong linear correlation with increasing amyloid burden, but underestimated fluorescence yield and suffered from localization artifacts. Full-angle measurements did not improve upon the transmission reconstruction qualitatively or in semi-quantitative measures of accuracy; anatomical and initial-value priors did improve reconstruction localization and accuracy for both transmission and full-angle schemes. Region-based reconstructions, in which the unknowns were reduced to a few distinct anatomical regions, produced highly accurate yield estimates for cortex, hippocampus and brain regions, even with a reduced number of measurements (144 source-detector pairs).
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Affiliation(s)
- S B Raymond
- The Harvard-MIT Division of Health Sciences and Technology, 77 Mass Ave., E25-519, Cambridge, MA 02139, USA
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24
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Feng J, Jia K, Qin C, Yan G, Zhu S, Zhang X, Liu J, Tian J. Three-dimensional bioluminescence tomography based on Bayesian approach. OPTICS EXPRESS 2009; 17:16834-16848. [PMID: 19770900 DOI: 10.1364/oe.17.016834] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Bioluminescence tomography (BLT) poses a typical ill-posed inverse problem with a large number of unknowns and a relatively limited number of boundary measurements. It is indispensable to incorporate a priori information into the inverse problem formulation in order to obtain viable solutions. In the paper, Bayesian approach has been firstly suggested to incorporate multiple types of a priori information for BLT reconstruction. Meanwhile, a generalized adaptive Gaussian Markov random field (GAGMRF) prior model for unknown source density estimation is developed to further reduce the ill-posedness of BLT on the basis of finite element analysis. Then the distribution of bioluminescent source can be acquired by maximizing the log posterior probability with respect to a noise parameter and the unknown source density. Furthermore, the use of finite element method makes the algorithm appropriate for complex heterogeneous phantom. The algorithm was validated by numerical simulation of a 3-D micro-CT mouse atlas and physical phantom experiment. The reconstructed results suggest that we are able to achieve high computational efficiency and accurate localization of bioluminescent source.
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Affiliation(s)
- Jinchao Feng
- The College of Electronic Information & Control Engineering, Beijing University of Technology, Beijing 100190, China
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25
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Daifa Wang, Xin Liu, Yanping Chen, Jing Bai. A Novel Finite-Element-Based Algorithm for Fluorescence Molecular Tomography of Heterogeneous Media. ACTA ACUST UNITED AC 2009; 13:766-73. [DOI: 10.1109/titb.2009.2015144] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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26
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Chen X, Gao X, Qu X, Liang J, Wang L, Yang D, Garofalakis A, Ripoll J, Tian J. A study of photon propagation in free-space based on hybrid radiosity-radiance theorem. OPTICS EXPRESS 2009; 17:16266-16280. [PMID: 19724626 DOI: 10.1364/oe.17.016266] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Noncontact optical imaging has attracted increasing attention in recent years due to its significant advantages on detection sensitivity, spatial resolution, image quality and system simplicity compared with contact measurement. However, photon transport simulation in free-space is still an extremely challenging topic for the complexity of the optical system. For this purpose, this paper proposes an analytical model for photon propagation in free-space based on hybrid radiosity-radiance theorem (HRRT). It combines Lambert's cosine law and the radiance theorem to handle the influence of the complicated lens and to simplify the photon transport process in the optical system. The performance of the proposed model is evaluated and validated with numerical simulations and physical experiments. Qualitative comparison results of flux distribution at the detector are presented. In particular, error analysis demonstrates the feasibility and potential of the proposed model for simulating photon propagation in free-space.
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Affiliation(s)
- Xueli Chen
- Video & Image Processing System Lab, School of Electronic Engineering, Xidian University, Xi'an 710071, China
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27
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Chaudhari AJ, Ahn S, Levenson R, Badawi RD, Cherry SR, Leahy RM. Excitation spectroscopy in multispectral optical fluorescence tomography: methodology, feasibility and computer simulation studies. Phys Med Biol 2009; 54:4687-704. [PMID: 19590118 DOI: 10.1088/0031-9155/54/15/004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Molecular probes used for in vivo optical fluorescence tomography (OFT) studies in small animals are typically chosen such that their emission spectra lie in the 680-850 nm wavelength range. This is because tissue attenuation in this spectral band is relatively low, allowing optical photons even from deep sites in tissue to reach the animal surface and consequently be detected by a CCD camera. The wavelength dependence of tissue optical properties within the 680-850 nm band can be exploited for emitted light by measuring fluorescent data via multispectral approaches and incorporating the spectral dependence of these optical properties into the OFT inverse problem-that of reconstructing underlying 3D fluorescent probe distributions from optical data collected on the animal surface. However, in the aforementioned spectral band, due to only small variations in the tissue optical properties, multispectral emission data, though superior for image reconstruction compared to achromatic data, tend to be somewhat redundant. A different spectral approach for OFT is to capitalize on the larger variations in the optical properties of tissue for excitation photons than for the emission photons by using excitation at multiple wavelengths as a means of decoding source depth in tissue. The full potential of spectral approaches in OFT can be realized by a synergistic combination of these two approaches, that is, exciting the underlying fluorescent probe at multiple wavelengths and measuring emission data multispectrally. In this paper, we describe a method that incorporates both excitation and emission spectral information into the OFT inverse problem. We describe a linear algebraic formulation of the multiple wavelength illumination-multispectral detection forward model for OFT and compare it to models that use only excitation at multiple wavelengths or those that use only multispectral detection techniques. This study is carried out in a realistic inhomogeneous mouse atlas using singular value decomposition and analysis of reconstructed spatial resolution versus noise. For simplicity, quantitative results have been shown for one representative fluorescent probe (Alexa 700) and effects due to tissue autofluorescence have not been taken into account. We also demonstrate the performance of our method for 3D reconstruction of tumors in a simulated mouse model of metastatic human hepatocellular carcinoma.
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Affiliation(s)
- Abhijit J Chaudhari
- Department of Biomedical Engineering, University of California-Davis, Davis, CA 95616, USA.
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28
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Davis SC, Pogue BW, Tuttle SB, Dehghani H, Paulsen KD. Spectral distortion in diffuse molecular luminescence tomography in turbid media. JOURNAL OF APPLIED PHYSICS 2009; 105:102024. [PMID: 20157444 PMCID: PMC2821414 DOI: 10.1063/1.3116130] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Accepted: 08/07/2008] [Indexed: 05/28/2023]
Abstract
The influence of tissue optical properties on the shape of near-infrared (NIR) fluorescence emission spectra propagating through multiple centimeters of tissue-like media was investigated. Fluorescence emission spectra measured from 6 cm homogeneous tissue-simulating phantoms show dramatic spectral distortion which results in emission peak shifts of up to 60 nm in wavelength. Measured spectral shapes are highly dependent on the photon path length and the scattered photon field in the NIR amplifies the wavelength-dependent absorption of the fluorescence spectra. Simulations of the peak propagation using diffusion modeling describe the experimental observations and confirm the path length dependence of fluorescence emission spectra. Spectral changes are largest for long path length measurements and thus will be most important in human tomography studies in the NIR. Spectrally resolved detection strategies are required to detect and interpret these effects which may otherwise produce erroneous intensity measurements. This observed phenomenon is analogous to beam hardening in x-ray tomography, which can lead to image artifacts without appropriate compensation. The peak shift toward longer wavelengths, and therefore lower energy photons, observed for NIR luminescent signals propagating through tissue may readily be described as a beam softening phenomenon.
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29
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Deliolanis NC, Dunham J, Wurdinger T, Figueiredo JL, Tannous BA, Ntziachristos V. In-vivo imaging of murine tumors using complete-angle projection fluorescence molecular tomography. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:030509. [PMID: 19566290 PMCID: PMC2881930 DOI: 10.1117/1.3149854] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We interrogate the ability of free-space fluorescence tomography to image small animals in vivo using charge-coupled device (CCD) camera measurements over 360-deg noncontact projections. We demonstrate the performance of normalized dual-wavelength measurements that are essential for in-vivo use, as they account for the heterogeneous distribution of photons in tissue. In-vivo imaging is then showcased on mouse lung and brain tumors cross-validated by x-ray microcomputed tomography and histology.
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30
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Kepshire DS, Gibbs-Strauss SL, Gibbs-Struass SL, O'Hara JA, Hutchins M, Mincu N, Leblond F, Khayat M, Dehghani H, Srinivasan S, Pogue BW. Imaging of glioma tumor with endogenous fluorescence tomography. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:030501. [PMID: 19566285 PMCID: PMC2810635 DOI: 10.1117/1.3127202] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Tomographic imaging of a glioma tumor with endogenous fluorescence is demonstrated using a noncontact single-photon counting fan-beam acquisition system interfaced with microCT imaging. The fluorescence from protoporphyrin IX (PpIX) was found to be detectable, and allowed imaging of the tumor from within the cranium, even though the tumor presence was not visible in the microCT image. The combination of single-photon counting detection and normalized fluorescence to transmission detection at each channel allowed robust imaging of the signal. This demonstrated use of endogenous fluorescence stimulation from aminolevulinic acid (ALA) and provides the first in vivo demonstration of deep tissue tomographic imaging with protoporphyrin IX.
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31
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Zhang X, Badea C. Effects of sampling strategy on image quality in noncontact panoramic fluorescence diffuse optical tomography for small animal imaging. OPTICS EXPRESS 2009; 17:5125-38. [PMID: 19333276 PMCID: PMC2664524 DOI: 10.1364/oe.17.005125] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Fluorescence diffuse optical tomography is an emerging technology for molecular imaging with recent technological advances in biomarkers and photonics. The introduction of noncontact imaging methods enables very large-scale data acquisition that is orders of magnitude larger than that from earlier systems. In this study, the effects of sampling strategy on image quality were investigated using an imaging phantom mimicking small animals and further analyzed using singular value analysis (SVA). The sampling strategy was represented in terms of a number of key acquisition parameters, namely the numbers of sources, detectors, and imaging angles. A number of metrics were defined to quantitatively evaluate image quality. The effects of acquisition parameters on image quality were subsequently studied by varying each of the parameters within a reasonable range while maintaining the other parameters constant, a method analogue to partial derivative in mathematical analysis. It was found that image quality improves at a much slower rate if the acquisition parameters are above certain critical values (approximately 5 sources, approximately 15 detectors, and approximately 20 angles for our system). These critical values remain virtually the same even if other acquisition parameters are doubled. It was also found that increasing different acquisition parameters improves image quality with different efficiencies in terms of the number of measurements: for a system characterized by a smaller threshold in SVA (less than 10(-5) in our study), the number of sources is the most efficient, followed by the number of detectors and subsequently the number of imaging angles. However, for systems characterized by a larger threshold, the numbers of sources and angles are equally more efficient than the number of detectors.
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Affiliation(s)
- Xiaofeng Zhang
- Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC 27710, USA.
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32
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Waerzeggers Y, Monfared P, Viel T, Winkeler A, Voges J, Jacobs AH. Methods to monitor gene therapy with molecular imaging. Methods 2009; 48:146-60. [PMID: 19318125 DOI: 10.1016/j.ymeth.2009.03.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Accepted: 03/11/2009] [Indexed: 01/08/2023] Open
Abstract
Recent progress in scientific and clinical research has made gene therapy a promising option for efficient and targeted treatment of several inherited and acquired disorders. One of the most critical issues for ensuring success of gene-based therapies is the development of technologies for non-invasive monitoring of the distribution and kinetics of vector-mediated gene expression. In recent years many molecular imaging techniques for safe, repeated and high-resolution in vivo imaging of gene expression have been developed and successfully used in animals and humans. In this review molecular imaging techniques for monitoring of gene therapy are described and specific use of these methods in the different steps of a gene therapy protocol from gene delivery to assessment of therapy response is illustrated. Linking molecular imaging (MI) to gene therapy will eventually help to improve the efficacy and safety of current gene therapy protocols for human application and support future individualized patient treatment.
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Affiliation(s)
- Yannic Waerzeggers
- Laboratory for Gene Therapy and Molecular Imaging, Max Planck Institute for Neurological Research and Faculty of Medicine, University of Cologne, Gleuelerstrasse 50, Cologne 50931, Germany
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Zacharopoulos AD, Svenmarker P, Axelsson J, Schweiger M, Arridge SR, Andersson-Engels S. A matrix-free algorithm for multiple wavelength fluorescence tomography. OPTICS EXPRESS 2009; 17:3025-35. [PMID: 19259141 DOI: 10.1364/oe.17.003042] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
In the recent years, there has been an increase in applications of non-contact diffusion optical tomography. Especially when the objective is the recovery of fluorescence targets. The non-contact acquisition systems with the use of a CCD-camera produce much denser sampled boundary data sets than fibre-based systems. When model-based reconstruction methods are used, that rely on the inversion of a derivative operator, the large number of measurements poses a challenge since the explicit formulation and storage of the Jacobian matrix could be in general not feasible. This problem is aggravated further in applications, where measurements at multiple wavelengths are used. We present a matrix-free model-based reconstruction method, that addresses the problems of large data sets and reduces the computational cost and memory requirements for the reconstruction. The idea behind the matrix-free method is that information about the Jacobian matrix could be available through matrix times vector products so that the creation and storage of big matrices can be avoided. We tested the method for multiple wavelength fluorescence tomography with simulated and experimental data from phantom experiments, and we found substantial benefits in computational times and memory requirements.
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34
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Iglesias I, Ripoll J. Scanning illumination-acquisition system for noncontact optical tomography. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:024003. [PMID: 19405733 DOI: 10.1117/1.3103290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A new method for the detection of light traversing a diffuser/nondiffuser interface and its simultaneous determination for optical tomography is proposed, and the preliminary results are shown. The method is based on the use of a point detector and two uncoupled scanning systems-one for illumination and the other for registration-together with active modification of the optics guided by the surface topography to generate virtual detectors on the interface.
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Affiliation(s)
- Ignacio Iglesias
- Universidad de Murcia, Departamento de Fisica, Campus de Espinardo, 30100 Murcia, Spain.
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35
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Zhang X, Badea C, Jacob M, Johnson GA. Development of a noncontact 3-D fluorescence tomography system for small animal in vivo imaging. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2009; 7191:nihpa106691. [PMID: 19587837 DOI: 10.1117/12.808199] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Fluorescence imaging is an important tool for tracking molecular-targeting probes in preclinical studies. It offers high sensitivity, but nonetheless low spatial resolution compared to other leading imaging methods such CT and MRI. We demonstrate our methodological development in small animal in vivo whole-body imaging using fluorescence tomography. We have implemented a noncontact fluid-free fluorescence diffuse optical tomography system that uses a raster-scanned continuous-wave diode laser as the light source and an intensified CCD camera as the photodetector. The specimen is positioned on a motorized rotation stage. Laser scanning, data acquisition, and stage rotation are controlled via LabVIEW applications. The forward problem in the heterogeneous medium is based on a normalized Born method, and the sensitivity function is determined using a Monte Carlo method. The inverse problem (image reconstruction) is performed using a regularized iterative algorithm, in which the cost function is defined as a weighted sum of the L-2 norms of the solution image, the residual error, and the image gradient. The relative weights are adjusted by two independent regularization parameters. Our initial tests of this imaging system were performed with an imaging phantom that consists of a translucent plastic cylinder filled with tissue-simulating liquid and two thin-wall glass tubes containing indocyanine green. The reconstruction is compared to the output of a finite element method-based software package NIRFAST and has produced promising results.
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Affiliation(s)
- Xiaofeng Zhang
- Dept. of Radiology, Duke University Medical Center, Box 3302, Durham, NC, 27710
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36
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Turchin IV, Kamensky VA, Plehanov VI, Orlova AG, Kleshnin MS, Fiks II, Shirmanova MV, Meerovich IG, Arslanbaeva LR, Jerdeva VV, Savitsky AP. Fluorescence diffuse tomography for detection of red fluorescent protein expressed tumors in small animals. JOURNAL OF BIOMEDICAL OPTICS 2008; 13:041310. [PMID: 19021318 DOI: 10.1117/1.2953528] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A fluorescence diffuse tomography (FDT) setup for monitoring tumor growth in small animals has been created. In this setup an animal is scanned in the transilluminative configuration by a single source and detector pair. To remove stray light in the detection system, we used a combination of interferometric and absorption filters. To reduce the scanning time, an experimental animal was scanned using the following algorithm: (1) large-step scanning to obtain a general view of the animal (source and detector move synchronously); (2) selection of the fluorescing region; and (3) small-step scanning of the selected region and different relative shifts between the source and detector to obtain sufficient information for 3D reconstruction. We created a reconstruction algorithm based on the Holder norm to estimate the fluorophore distribution. This algorithm converges to the solution with a minimum number of fluorescing zones. The use of tumor cell lines transfected with fluorescent proteins allowed us to conduct intravital monitoring studies. Cell lines of human melanomas Mel-P, Mel-Ibr, Mel-Kor, and human embryonic kidney HEK293 Phoenix were transfected with DsRed-Express and Turbo-RFP genes. The emission of red fluorescent proteins (RFPs) in the long-wave optical range permits detection of deep-seated tumors. In vivo experiments were conducted immediately after subcutaneous injection of fluorescing cells into small animals.
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Affiliation(s)
- Ilya V Turchin
- Institute of Applied Physics RAS, 46 Ulyanov Street, 603950 Nizhny Novgorod, Russia.
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37
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Davis SC, Pogue BW, Springett R, Leussler C, Mazurkewitz P, Tuttle SB, Gibbs-Strauss SL, Jiang SS, Dehghani H, Paulsen KD. Magnetic resonance-coupled fluorescence tomography scanner for molecular imaging of tissue. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:064302. [PMID: 18601421 PMCID: PMC2678791 DOI: 10.1063/1.2919131] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Accepted: 04/13/2008] [Indexed: 05/19/2023]
Abstract
A multichannel spectrally resolved optical tomography system to image molecular targets in small animals from within a clinical MRI is described. Long source/detector fibers operate in contact mode and couple light from the tissue surface in the magnet bore to 16 spectrometers, each containing two optical gratings optimized for the near infrared wavelength range. High sensitivity, cooled charge coupled devices connected to each spectrograph provide detection of the spectrally resolved signal, with exposure times that are automated for acquisition at each fiber. The design allows spectral fitting of the remission light, thereby separating the fluorescence signal from the nonspecific background, which improves the accuracy and sensitivity when imaging low fluorophore concentrations. Images of fluorescence yield are recovered using a nonlinear reconstruction approach based on the diffusion approximation of photon propagation in tissue. The tissue morphology derived from the MR images serves as an imaging template to guide the optical reconstruction algorithm. Sensitivity studies show that recovered values of indocyanine green fluorescence yield are linear to concentrations of 1 nM in a 70 mm diameter homogeneous phantom, and detection is feasible to near 10 pM. Phantom data also demonstrate imaging capabilities of imperfect fluorophore uptake in tissue volumes of clinically relevant sizes. A unique rodent MR coil provides optical fiber access for simultaneous optical and MR data acquisition of small animals. A pilot murine study using an orthotopic glioma tumor model demonstrates optical-MRI imaging of an epidermal growth factor receptor targeted fluorescent probe in vivo.
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Affiliation(s)
- Scott C Davis
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA.
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