Sung-cheng Huang - Academia.edu (original) (raw)
Papers by Sung-cheng Huang
Because of its high selectivity and specificity for the imaging re- porter probe 9-(4-18F-fluoro-... more Because of its high selectivity and specificity for the imaging re- porter probe 9-(4-18F-fluoro-3-(hydroxymethyl)butyl)guanine (18F-FHBG), the herpes simplex virus type 1 thymidine kinase (HSV1-tk) variant sr39tk is actively being studied as a PET re- porter gene. We recently demonstrated the capability of using a prostate-specific transcriptional amplification PET reporter vector, AdTSTA-sr39tk, to target prostate cancer lymph node metastasis. However, one
IEEE Transactions on Nuclear Science, 1994
A technique that can register anatomic/structural brain images (e.g., MRI) with various functiona... more A technique that can register anatomic/structural brain images (e.g., MRI) with various functional images (e.g., PET-FDG and PET-FDOPA) of the same subject has been developed. The procedure of this technique includes the following steps: (1) segmentation of MRI brain images into gray matter (GM), white matter (WM), cerebral spinal fluid (CSF), and, muscle (MS) components, (2) assignment of appropriate radio-tracer
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2014
Large-molecule tracers, such as labeled antibodies, have shown success in immuno-PET for imaging ... more Large-molecule tracers, such as labeled antibodies, have shown success in immuno-PET for imaging of specific cell surface biomarkers. However, previous work has shown that localization of such tracers shows high levels of heterogeneity in target tissues, due to both the slow diffusion and the high affinity of these compounds. In this work, we investigate the effects of subvoxel spatial heterogeneity on measured time-activity curves in PET imaging and the effects of ignoring diffusion limitation on parameter estimates from kinetic modeling. Partial differential equations (PDE) were built to model a radially symmetric reaction-diffusion equation describing the activity of immuno-PET tracers. The effects of slower diffusion on measured time-activity curves and parameter estimates were measured in silico, and a modified Levenberg-Marquardt algorithm with Bayesian priors was developed to accurately estimate parameters from diffusion-limited data. This algorithm was applied to immuno-PET ...
Recent studies have shown that Alzheimer's disease (AD) is related to alteration in brain connect... more Recent studies have shown that Alzheimer's disease (AD) is related to alteration in brain connectivity networks. One type of connectivity, called effective connectivity, defined as the directional relationship between brain regions, is essential to brain function. However, there have been few studies on modeling the effective connectivity of AD and characterizing its difference from normal controls (NC). In this paper, we investigate the sparse Bayesian Network (BN) for effective connectivity modeling. Specifically, we propose a novel formulation for the structure learning of BNs, which involves one L1-norm penalty term to impose sparsity and another penalty to ensure the learned BN to be a directed acyclic graph -a required property of BNs. We show, through both theoretical analysis and extensive experiments on eleven moderate and large benchmark networks with various sample sizes, that the proposed method has much improved learning accuracy and scalability compared with ten competing algorithms. We apply the proposed method to FDG-PET images of 42 AD and 67 NC subjects, and identify the effective connectivity models for AD and NC, respectively. Our study reveals that the effective connectivity of AD is different from that of NC in many ways, including the global-scale effective connectivity, intra-lobe, interlobe, and inter-hemispheric effective connectivity distributions, as well as the effective connectivity associated with specific brain regions. These findings are consistent with known pathology and clinical progression of AD, and will contribute to AD knowledge discovery.
2006 IEEE Nuclear Science Symposium Conference Record, 2006
Quantitative microPET imaging provides the capability of performing biochemical and physiological... more Quantitative microPET imaging provides the capability of performing biochemical and physiological investigations. The collection of multiple blood samples over time is necessary for quantitative analysis. The procedure is challenging because the amount of blood volume is small in rats and mice. To overcome this issue, an automatic blood sampling system was developed using a novel microfluidic chip design to take
Journal of Computer Assisted Tomography, 1992
Positron emission tomography (PET) fluorodeoxyglucose (FDG) studies are useful for identifying fo... more Positron emission tomography (PET) fluorodeoxyglucose (FDG) studies are useful for identifying foci of increased FDG uptake in liver metastases, because of the high glycolytic rate of malignancies, as well as for monitoring changes in tumor glucose metabolism during treatment. We performed 15 kinetic PET FDG studies in four patients with metastatic liver disease. We produced parametric images of glucose metabolism in terms of the rate constant K (ml/min/g) for net phosphorylation of FDG. Tumor K values, estimated with nonlinear regression, correlated well with K values estimated with Patlak graphical analysis (r = 0.96), validating the assumption of low k4* values in liver metastases and supporting the use of pixel by pixel Patlak plot analysis of the data to generate parametric images. In normal liver, high levels of glucose-6-phosphatase produce much higher values of k4* than in liver metastases. Uncorrected Patlak graphical analysis underestimates K in normal liver, but this further increases the contrast between tumor and liver and facilitates both tumor detection and quantification. The technique is computationally feasible and is well suited for serial evaluations of tumor metabolism during treatment.
Journal of Cerebral Blood Flow & Metabolism, 1998
The authors developed and tested a method for the noninvasive quantification of the cerebral meta... more The authors developed and tested a method for the noninvasive quantification of the cerebral metabolic rate for glucose (CMRglc) using positron emission tomography (PET), 18F-fluoro-2-deoxyglucose, the Patlak method, and an image-derived input function. Dynamic PET data acquired 12 to 48 seconds after rapid tracer injection were summed to identify carotid artery regions of interest (ROIs). The input function then was generated from the carotid artery ROIs. To correct spillover, the early summed image was superimposed over the last PET frame, a tissue ROI was drawn around the carotid arteries, and a tissue time activity curve (TAC) was generated. Three venous samples were drawn from the tracer injection site at a later time and used for the spillover and partial volume correction by non-negative least squares method. Twenty-six patient data sets were studied. It was found that the image-derived input function was comparable in shape and magnitude to the one obtained by arterial blood sampling. Moreover, no significant difference was found between CMRglc estimated by the Patlak method using either the arterial blood sampling data or the image-derived input function.
IEEE Transactions on Nuclear Science, 1995
IEEE Transactions on Medical Imaging, 1998
In this paper, we developed and tested strategies for estimating myocardial blood flow (MBF) and ... more In this paper, we developed and tested strategies for estimating myocardial blood flow (MBF) and generating MBF parametric images using positron emission tomography (PET), N-13 ammonia, and the generalized linear least square (GLLS) method. GLLS was generalized to the general linear compartment model, modified for the correction of spillover, validated using simulated N-13 ammonia data, and examined using PET data from several patient studies. In comparison to the standard model-fitting procedure, the GLLS method provided similar accuracy and superior computational speed.
![Research paper thumbnail of Blood-brain barrier and neuronal membrane transport of 6-[ 18F]fluoro- l-DOPA 1 1 Abbreviations: AAAD, aromatic l-amino acid decarboxylase; BBB, blood-brain barrier; BUI, brain uptake index; carbidopa, l-α-hydrazino-α-methyl-β-(3,4-dihydroxyphenyl)propionic acid; l-DOPA, l-3,4-dihydroxyphenylalan...](https://attachments.academia-assets.com/44743037/thumbnails/1.jpg)
](Wear, 2001
The transport of 6-[18F]fluoro-l-3,4-dihydroxyphenylalanine ([18F]FDOPA) across the blood-brain b... more The transport of 6-[18F]fluoro-l-3,4-dihydroxyphenylalanine ([18F]FDOPA) across the blood-brain barrier (BBB) and neuronal membranes was compared with that of l-3,4-dihydroxyphenylalanine (l-DOPA) in rats. The carotid injection method was used as a direct measurement of [18F]FDOPA, 1-[14C]-l-DOPA, and 3-[14C]-l-DOPA transport across the BBB, while isolated nerve terminals were used to examine neuronal membrane transport of [3H]-l-DOPA. [18F]FDOPA appeared to use the same
Biomedical Engineering, 1996
A new double modeling approach for dynamic cardiac studies with positron emission tomography (PET... more A new double modeling approach for dynamic cardiac studies with positron emission tomography (PET) to estimate physiological parameters is proposed. This approach is exemplified by tracer fluorodeoxyglucose (FDG) studies and estimation of myocardial metabolic rate of glucose (MMRGlc). A separate input function model characterising the tracer kinetics in plasma is used to account for the measurement noise and spillover problems of the input curve obtained from the left ventricular region on the PET images. Measured left ventricle (LV) plasma time-activity and tissue time-activity curves are fitted simultaneously with cross contaminations by this input function model and the FDG model.
2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC), 2009
... Koon-Pong Wong, Member, IEEE, Sung-Cheng Huang, Fellow, IEEE, Vladimir Kepe, Gary W. Small, a... more ... Koon-Pong Wong, Member, IEEE, Sung-Cheng Huang, Fellow, IEEE, Vladimir Kepe, Gary W. Small, and Jorge R. Barrio ... Due to its simplicity as compared to other reference tissue modeling methods, Logan graphical analysis with cerebellum as reference region has been ...
2006 IEEE Nuclear Science Symposium Conference Record, 2006
Abstract Accurate determination of the input function is essential for absolute quantification of... more Abstract Accurate determination of the input function is essential for absolute quantification of physiological parameters in positron emission tomography (PET) and single-photon emission computed tomography (SPECT) imaging. Uncertainties associated with the input ...
Proceedings of the National Academy of Sciences of the United States of America, Jan 6, 2015
Chronic traumatic encephalopathy (CTE) is an acquired primary tauopathy with a variety of cogniti... more Chronic traumatic encephalopathy (CTE) is an acquired primary tauopathy with a variety of cognitive, behavioral, and motor symptoms linked to cumulative brain damage sustained from single, episodic, or repetitive traumatic brain injury (TBI). No definitive clinical diagnosis for this condition exists. In this work, we used [F-18]FDDNP PET to detect brain patterns of neuropathology distribution in retired professional American football players with suspected CTE (n = 14) and compared results with those of cognitively intact controls (n = 28) and patients with Alzheimer's dementia (AD) (n = 24), a disease that has been cognitively associated with CTE. [F-18]FDDNP PET imaging results in the retired players suggested the presence of neuropathological patterns consistent with models of concussion wherein brainstem white matter tracts undergo early axonal damage and cumulative axonal injuries along subcortical, limbic, and cortical brain circuitries supporting mood, emotions, and beha...
The American journal of geriatric psychiatry : official journal of the American Association for Geriatric Psychiatry
The authors used 2-(1-(6-[(2-[18F]fluoroethyl)(methyl)amino]-2-naphthyl)ethylidene)malononitrile ... more The authors used 2-(1-(6-[(2-[18F]fluoroethyl)(methyl)amino]-2-naphthyl)ethylidene)malononitrile ([18F]FDDNP), a hydrophobic radiofluorinated derivative of 2-(1-[6-(dimethylamino)-2-naphthyl]ethylidene)malononitrile (DDNP), in conjunction with positron emission tomography to determine the localization and load of neurofibrillary tangles (NFTs) and beta-amyloid senile plaques (APs) in the brains of living Alzheimer disease (AD) patients. Previous work illustrated the in vitro binding characteristics of [18F]FDDNP to synthetic beta-amyloid(1-40) fibrils and to NFTs and APs in human AD brain specimens. In the present study, greater accumulation and slower clearance was observed in AP- and NFT-dense brain areas and correlated with lower memory performance scores. The relative residence time of the probe in brain regions affected by AD was significantly greater in patients with AD (n=9) than in control subjects (n=7; p=0.0007). This noninvasive technique for monitoring AP and NFT develop...
Information processing in medical imaging : proceedings of the ... conference, 2005
This paper presents a new approach to inverse consistent image registration. A uni-directional al... more This paper presents a new approach to inverse consistent image registration. A uni-directional algorithm is developed using symmetric cost functionals and regularizers. Instead of enforcing inverse consistency using an additional penalty that penalizes inconsistency error, the new algorithm directly models the backward mapping by inverting the forward mapping. The resulting minimization problem can then be solved uni-directionally involving only the forward mapping, without optimizing in the backward direction. Lastly, we evaluated the algorithm by applying it to the serial MRI scans of a clinical case of semantic dementia. The statistical distributions of the local volume change (Jacobian) maps were examined by considering the Kullback-Liebler distances on the material density functions. Contrary to common belief, the values of any non-trivial Jacobian map do not follow a log-normal distribution with zero mean. Statistically significant differences were detected between consistent ...
2011 IEEE Nuclear Science Symposium Conference Record, 2011
Intra-scan body movement (IBM) during a PET/CT study can degrade the image quality in subtle ways... more Intra-scan body movement (IBM) during a PET/CT study can degrade the image quality in subtle ways that are not easy for physicians to detect and can thus affect the diagnostic value of the images. In this study, we propose a method for identifying regions on a PET/CT image that are affected by IBM. The method is based on bootstrapping the
2007 IEEE Nuclear Science Symposium Conference Record, 2007
Positron emission tomography (PET) with 2-(1-{6- [(2-[18F]fluoroethyl)(methyl)amino]-2-naphthyl}e... more Positron emission tomography (PET) with 2-(1-{6- [(2-[18F]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malo-nonitrile ([18F]FDDNP) has been used for in vivo imaging of amyloid plaques and neurofibrillary tangles, the neuopathological hallmarks of Alzheimer's disease (AD). The purpose of this study was to assess seven noninvasive methods for the estimation of the distribution volume ratio (DVR), as a measure of binding density of [18F]FDDNP in human brain, using
![Research paper thumbnail of Influence of dietary state and insulin on myocardial, skeletal muscle and brain [18F]-fluorodeoxyglucose kinetics in mice](https://attachments.academia-assets.com/44743033/thumbnails/1.jpg)
](EJNMMI Research, 2011
We evaluated the effect of insulin stimulation and dietary changes on myocardial, skeletal muscle... more We evaluated the effect of insulin stimulation and dietary changes on myocardial, skeletal muscle and brain [ 18 F]-fluorodeoxyglucose (FDG) kinetics and uptake in vivo in intact mice.
PloS one, 2014
Head movement during a dynamic brain PET/CT imaging results in mismatch between CT and dynamic PE... more Head movement during a dynamic brain PET/CT imaging results in mismatch between CT and dynamic PET images. It can cause artifacts in CT-based attenuation corrected PET images, thus affecting both the qualitative and quantitative aspects of the dynamic PET images and the derived parametric images. In this study, we developed an automated retrospective image-based movement correction (MC) procedure. The MC method first registered the CT image to each dynamic PET frames, then re-reconstructed the PET frames with CT-based attenuation correction, and finally re-aligned all the PET frames to the same position. We evaluated the MC method's performance on the Hoffman phantom and dynamic FDDNP and FDG PET/CT images of patients with neurodegenerative disease or with poor compliance. Dynamic FDDNP PET/CT images (65 min) were obtained from 12 patients and dynamic FDG PET/CT images (60 min) were obtained from 6 patients. Logan analysis with cerebellum as the reference region was used to gene...
Because of its high selectivity and specificity for the imaging re- porter probe 9-(4-18F-fluoro-... more Because of its high selectivity and specificity for the imaging re- porter probe 9-(4-18F-fluoro-3-(hydroxymethyl)butyl)guanine (18F-FHBG), the herpes simplex virus type 1 thymidine kinase (HSV1-tk) variant sr39tk is actively being studied as a PET re- porter gene. We recently demonstrated the capability of using a prostate-specific transcriptional amplification PET reporter vector, AdTSTA-sr39tk, to target prostate cancer lymph node metastasis. However, one
IEEE Transactions on Nuclear Science, 1994
A technique that can register anatomic/structural brain images (e.g., MRI) with various functiona... more A technique that can register anatomic/structural brain images (e.g., MRI) with various functional images (e.g., PET-FDG and PET-FDOPA) of the same subject has been developed. The procedure of this technique includes the following steps: (1) segmentation of MRI brain images into gray matter (GM), white matter (WM), cerebral spinal fluid (CSF), and, muscle (MS) components, (2) assignment of appropriate radio-tracer
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2014
Large-molecule tracers, such as labeled antibodies, have shown success in immuno-PET for imaging ... more Large-molecule tracers, such as labeled antibodies, have shown success in immuno-PET for imaging of specific cell surface biomarkers. However, previous work has shown that localization of such tracers shows high levels of heterogeneity in target tissues, due to both the slow diffusion and the high affinity of these compounds. In this work, we investigate the effects of subvoxel spatial heterogeneity on measured time-activity curves in PET imaging and the effects of ignoring diffusion limitation on parameter estimates from kinetic modeling. Partial differential equations (PDE) were built to model a radially symmetric reaction-diffusion equation describing the activity of immuno-PET tracers. The effects of slower diffusion on measured time-activity curves and parameter estimates were measured in silico, and a modified Levenberg-Marquardt algorithm with Bayesian priors was developed to accurately estimate parameters from diffusion-limited data. This algorithm was applied to immuno-PET ...
Recent studies have shown that Alzheimer's disease (AD) is related to alteration in brain connect... more Recent studies have shown that Alzheimer's disease (AD) is related to alteration in brain connectivity networks. One type of connectivity, called effective connectivity, defined as the directional relationship between brain regions, is essential to brain function. However, there have been few studies on modeling the effective connectivity of AD and characterizing its difference from normal controls (NC). In this paper, we investigate the sparse Bayesian Network (BN) for effective connectivity modeling. Specifically, we propose a novel formulation for the structure learning of BNs, which involves one L1-norm penalty term to impose sparsity and another penalty to ensure the learned BN to be a directed acyclic graph -a required property of BNs. We show, through both theoretical analysis and extensive experiments on eleven moderate and large benchmark networks with various sample sizes, that the proposed method has much improved learning accuracy and scalability compared with ten competing algorithms. We apply the proposed method to FDG-PET images of 42 AD and 67 NC subjects, and identify the effective connectivity models for AD and NC, respectively. Our study reveals that the effective connectivity of AD is different from that of NC in many ways, including the global-scale effective connectivity, intra-lobe, interlobe, and inter-hemispheric effective connectivity distributions, as well as the effective connectivity associated with specific brain regions. These findings are consistent with known pathology and clinical progression of AD, and will contribute to AD knowledge discovery.
2006 IEEE Nuclear Science Symposium Conference Record, 2006
Quantitative microPET imaging provides the capability of performing biochemical and physiological... more Quantitative microPET imaging provides the capability of performing biochemical and physiological investigations. The collection of multiple blood samples over time is necessary for quantitative analysis. The procedure is challenging because the amount of blood volume is small in rats and mice. To overcome this issue, an automatic blood sampling system was developed using a novel microfluidic chip design to take
Journal of Computer Assisted Tomography, 1992
Positron emission tomography (PET) fluorodeoxyglucose (FDG) studies are useful for identifying fo... more Positron emission tomography (PET) fluorodeoxyglucose (FDG) studies are useful for identifying foci of increased FDG uptake in liver metastases, because of the high glycolytic rate of malignancies, as well as for monitoring changes in tumor glucose metabolism during treatment. We performed 15 kinetic PET FDG studies in four patients with metastatic liver disease. We produced parametric images of glucose metabolism in terms of the rate constant K (ml/min/g) for net phosphorylation of FDG. Tumor K values, estimated with nonlinear regression, correlated well with K values estimated with Patlak graphical analysis (r = 0.96), validating the assumption of low k4* values in liver metastases and supporting the use of pixel by pixel Patlak plot analysis of the data to generate parametric images. In normal liver, high levels of glucose-6-phosphatase produce much higher values of k4* than in liver metastases. Uncorrected Patlak graphical analysis underestimates K in normal liver, but this further increases the contrast between tumor and liver and facilitates both tumor detection and quantification. The technique is computationally feasible and is well suited for serial evaluations of tumor metabolism during treatment.
Journal of Cerebral Blood Flow & Metabolism, 1998
The authors developed and tested a method for the noninvasive quantification of the cerebral meta... more The authors developed and tested a method for the noninvasive quantification of the cerebral metabolic rate for glucose (CMRglc) using positron emission tomography (PET), 18F-fluoro-2-deoxyglucose, the Patlak method, and an image-derived input function. Dynamic PET data acquired 12 to 48 seconds after rapid tracer injection were summed to identify carotid artery regions of interest (ROIs). The input function then was generated from the carotid artery ROIs. To correct spillover, the early summed image was superimposed over the last PET frame, a tissue ROI was drawn around the carotid arteries, and a tissue time activity curve (TAC) was generated. Three venous samples were drawn from the tracer injection site at a later time and used for the spillover and partial volume correction by non-negative least squares method. Twenty-six patient data sets were studied. It was found that the image-derived input function was comparable in shape and magnitude to the one obtained by arterial blood sampling. Moreover, no significant difference was found between CMRglc estimated by the Patlak method using either the arterial blood sampling data or the image-derived input function.
IEEE Transactions on Nuclear Science, 1995
IEEE Transactions on Medical Imaging, 1998
In this paper, we developed and tested strategies for estimating myocardial blood flow (MBF) and ... more In this paper, we developed and tested strategies for estimating myocardial blood flow (MBF) and generating MBF parametric images using positron emission tomography (PET), N-13 ammonia, and the generalized linear least square (GLLS) method. GLLS was generalized to the general linear compartment model, modified for the correction of spillover, validated using simulated N-13 ammonia data, and examined using PET data from several patient studies. In comparison to the standard model-fitting procedure, the GLLS method provided similar accuracy and superior computational speed.
Wear, 2001
The transport of 6-[18F]fluoro-l-3,4-dihydroxyphenylalanine ([18F]FDOPA) across the blood-brain b... more The transport of 6-[18F]fluoro-l-3,4-dihydroxyphenylalanine ([18F]FDOPA) across the blood-brain barrier (BBB) and neuronal membranes was compared with that of l-3,4-dihydroxyphenylalanine (l-DOPA) in rats. The carotid injection method was used as a direct measurement of [18F]FDOPA, 1-[14C]-l-DOPA, and 3-[14C]-l-DOPA transport across the BBB, while isolated nerve terminals were used to examine neuronal membrane transport of [3H]-l-DOPA. [18F]FDOPA appeared to use the same
Biomedical Engineering, 1996
A new double modeling approach for dynamic cardiac studies with positron emission tomography (PET... more A new double modeling approach for dynamic cardiac studies with positron emission tomography (PET) to estimate physiological parameters is proposed. This approach is exemplified by tracer fluorodeoxyglucose (FDG) studies and estimation of myocardial metabolic rate of glucose (MMRGlc). A separate input function model characterising the tracer kinetics in plasma is used to account for the measurement noise and spillover problems of the input curve obtained from the left ventricular region on the PET images. Measured left ventricle (LV) plasma time-activity and tissue time-activity curves are fitted simultaneously with cross contaminations by this input function model and the FDG model.
2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC), 2009
... Koon-Pong Wong, Member, IEEE, Sung-Cheng Huang, Fellow, IEEE, Vladimir Kepe, Gary W. Small, a... more ... Koon-Pong Wong, Member, IEEE, Sung-Cheng Huang, Fellow, IEEE, Vladimir Kepe, Gary W. Small, and Jorge R. Barrio ... Due to its simplicity as compared to other reference tissue modeling methods, Logan graphical analysis with cerebellum as reference region has been ...
2006 IEEE Nuclear Science Symposium Conference Record, 2006
Abstract Accurate determination of the input function is essential for absolute quantification of... more Abstract Accurate determination of the input function is essential for absolute quantification of physiological parameters in positron emission tomography (PET) and single-photon emission computed tomography (SPECT) imaging. Uncertainties associated with the input ...
Proceedings of the National Academy of Sciences of the United States of America, Jan 6, 2015
Chronic traumatic encephalopathy (CTE) is an acquired primary tauopathy with a variety of cogniti... more Chronic traumatic encephalopathy (CTE) is an acquired primary tauopathy with a variety of cognitive, behavioral, and motor symptoms linked to cumulative brain damage sustained from single, episodic, or repetitive traumatic brain injury (TBI). No definitive clinical diagnosis for this condition exists. In this work, we used [F-18]FDDNP PET to detect brain patterns of neuropathology distribution in retired professional American football players with suspected CTE (n = 14) and compared results with those of cognitively intact controls (n = 28) and patients with Alzheimer's dementia (AD) (n = 24), a disease that has been cognitively associated with CTE. [F-18]FDDNP PET imaging results in the retired players suggested the presence of neuropathological patterns consistent with models of concussion wherein brainstem white matter tracts undergo early axonal damage and cumulative axonal injuries along subcortical, limbic, and cortical brain circuitries supporting mood, emotions, and beha...
The American journal of geriatric psychiatry : official journal of the American Association for Geriatric Psychiatry
The authors used 2-(1-(6-[(2-[18F]fluoroethyl)(methyl)amino]-2-naphthyl)ethylidene)malononitrile ... more The authors used 2-(1-(6-[(2-[18F]fluoroethyl)(methyl)amino]-2-naphthyl)ethylidene)malononitrile ([18F]FDDNP), a hydrophobic radiofluorinated derivative of 2-(1-[6-(dimethylamino)-2-naphthyl]ethylidene)malononitrile (DDNP), in conjunction with positron emission tomography to determine the localization and load of neurofibrillary tangles (NFTs) and beta-amyloid senile plaques (APs) in the brains of living Alzheimer disease (AD) patients. Previous work illustrated the in vitro binding characteristics of [18F]FDDNP to synthetic beta-amyloid(1-40) fibrils and to NFTs and APs in human AD brain specimens. In the present study, greater accumulation and slower clearance was observed in AP- and NFT-dense brain areas and correlated with lower memory performance scores. The relative residence time of the probe in brain regions affected by AD was significantly greater in patients with AD (n=9) than in control subjects (n=7; p=0.0007). This noninvasive technique for monitoring AP and NFT develop...
Information processing in medical imaging : proceedings of the ... conference, 2005
This paper presents a new approach to inverse consistent image registration. A uni-directional al... more This paper presents a new approach to inverse consistent image registration. A uni-directional algorithm is developed using symmetric cost functionals and regularizers. Instead of enforcing inverse consistency using an additional penalty that penalizes inconsistency error, the new algorithm directly models the backward mapping by inverting the forward mapping. The resulting minimization problem can then be solved uni-directionally involving only the forward mapping, without optimizing in the backward direction. Lastly, we evaluated the algorithm by applying it to the serial MRI scans of a clinical case of semantic dementia. The statistical distributions of the local volume change (Jacobian) maps were examined by considering the Kullback-Liebler distances on the material density functions. Contrary to common belief, the values of any non-trivial Jacobian map do not follow a log-normal distribution with zero mean. Statistically significant differences were detected between consistent ...
2011 IEEE Nuclear Science Symposium Conference Record, 2011
Intra-scan body movement (IBM) during a PET/CT study can degrade the image quality in subtle ways... more Intra-scan body movement (IBM) during a PET/CT study can degrade the image quality in subtle ways that are not easy for physicians to detect and can thus affect the diagnostic value of the images. In this study, we propose a method for identifying regions on a PET/CT image that are affected by IBM. The method is based on bootstrapping the
2007 IEEE Nuclear Science Symposium Conference Record, 2007
Positron emission tomography (PET) with 2-(1-{6- [(2-[18F]fluoroethyl)(methyl)amino]-2-naphthyl}e... more Positron emission tomography (PET) with 2-(1-{6- [(2-[18F]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malo-nonitrile ([18F]FDDNP) has been used for in vivo imaging of amyloid plaques and neurofibrillary tangles, the neuopathological hallmarks of Alzheimer's disease (AD). The purpose of this study was to assess seven noninvasive methods for the estimation of the distribution volume ratio (DVR), as a measure of binding density of [18F]FDDNP in human brain, using
EJNMMI Research, 2011
We evaluated the effect of insulin stimulation and dietary changes on myocardial, skeletal muscle... more We evaluated the effect of insulin stimulation and dietary changes on myocardial, skeletal muscle and brain [ 18 F]-fluorodeoxyglucose (FDG) kinetics and uptake in vivo in intact mice.
PloS one, 2014
Head movement during a dynamic brain PET/CT imaging results in mismatch between CT and dynamic PE... more Head movement during a dynamic brain PET/CT imaging results in mismatch between CT and dynamic PET images. It can cause artifacts in CT-based attenuation corrected PET images, thus affecting both the qualitative and quantitative aspects of the dynamic PET images and the derived parametric images. In this study, we developed an automated retrospective image-based movement correction (MC) procedure. The MC method first registered the CT image to each dynamic PET frames, then re-reconstructed the PET frames with CT-based attenuation correction, and finally re-aligned all the PET frames to the same position. We evaluated the MC method's performance on the Hoffman phantom and dynamic FDDNP and FDG PET/CT images of patients with neurodegenerative disease or with poor compliance. Dynamic FDDNP PET/CT images (65 min) were obtained from 12 patients and dynamic FDG PET/CT images (60 min) were obtained from 6 patients. Logan analysis with cerebellum as the reference region was used to gene...