The Experts below are selected from a list of 48345 Experts worldwide ranked by ideXlab platform
Gultekin Gulsen - One of the best experts on this subject based on the ideXlab platform.
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a photo multiplier tube based hybrid mri and frequency domain fluorescence tomography System for small animal imaging
Physics in Medicine and Biology, 2011Co-Authors: Yuting Lin, Michael Ghijsen, Hao Gao, Ning Liu, Orhan Nalcioglu, Gultekin GulsenAbstract: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.
Orhan Nalcioglu - One of the best experts on this subject based on the ideXlab platform.
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a photo multiplier tube based hybrid mri and frequency domain fluorescence tomography System for small animal imaging
Physics in Medicine and Biology, 2011Co-Authors: Yuting Lin, Michael Ghijsen, Hao Gao, Ning Liu, Orhan Nalcioglu, Gultekin GulsenAbstract: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.
Brian W Pogue - One of the best experts on this subject based on the ideXlab platform.
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effects of modeled optical properties on recovered fluorophore concentration during image guided fluorescence tomography
Proceedings of SPIE, 2013Co-Authors: Alisha V Dsouza, Brendan P Flynn, Stephen C Kanick, Brian W PogueAbstract:In fluorescence molecular tomography, optical measurements at the surface are used with diffusion theory modeling to reconstruct the maps of the fluorophore distribution in the tissue using an iterative error minimization algorithm. While normalizing the fluorescence signal with the excitation signal has been shown to correct for source and detector inconsistencies somewhat, this approach does not always correct for tissue heterogeneities and inaccuracies that are not matched by the forward diffusion model. Using computer simulations and an ultrasound-guided fluorescence tomography (Ft) System designed for spatial mapping of Protoporphyrin IX (PpIX), the errors in fluorophore concentration recovery by assignment of incorrect optical properties are analyzed. Using simulations and experiments, white light spectroscopy was used to obtain more accurate tissue properties for forward diffusion model, prior to Ft. Using white light spectroscopy the accuracy in Ft values improved by 97% on average and the minimal detectable concentration of PpIX with the System was 0.025μg/ml.
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a microcomputed tomography guided fluorescence tomography System for small animal molecular imaging
Review of Scientific Instruments, 2009Co-Authors: Dax Kepshire, Niculae Mincu, Michael Hutchins, Josiah Gruber, Hamid Dehghani, Justin Hypnarowski, Frederic Leblond, Mario Khayat, Brian W PogueAbstract:A prototype small animal imaging System was created for coupling fluorescence tomography (Ft) with x-ray microcomputed tomography (microCT). The Ft System has the potential to provide synergistic information content resultant from using microCT images as prior spatial information and then allows overlay of the Ft image onto the original microCT image. The Ft System was designed to use single photon counting to provide maximal sensitivity measurements in a noncontact geometry. Five parallel detector locations are used, each allowing simultaneous sampling of the fluorescence and transmitted excitation signals through the tissue. The calibration and linearity range performance of the System are outlined in a series of basic performance tests and phantom studies. The ability to image protoporphyrin IX in mouse phantoms was assessed and the System is ready for in vivo use to study biological production of this endogenous marker of tumors. This multimodality imaging System will have a wide range of applications in preclinical cancer research ranging from studies of the tumor microenvironment and treatment efficacy for emerging cancer therapeutics.
Yuting Lin - One of the best experts on this subject based on the ideXlab platform.
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a photo multiplier tube based hybrid mri and frequency domain fluorescence tomography System for small animal imaging
Physics in Medicine and Biology, 2011Co-Authors: Yuting Lin, Michael Ghijsen, Hao Gao, Ning Liu, Orhan Nalcioglu, Gultekin GulsenAbstract: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.
Hao Gao - One of the best experts on this subject based on the ideXlab platform.
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a photo multiplier tube based hybrid mri and frequency domain fluorescence tomography System for small animal imaging
Physics in Medicine and Biology, 2011Co-Authors: Yuting Lin, Michael Ghijsen, Hao Gao, Ning Liu, Orhan Nalcioglu, Gultekin GulsenAbstract: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.
