Abstract Brown adipose tissue (BAT) activation after cold exposure and its subsequent detection v... more Abstract Brown adipose tissue (BAT) activation after cold exposure and its subsequent detection via18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is mediated through norepinephrine (NE) induced β3-adrenoceptor activation. Pheochromocytoma/paragangliomas (PPGLs), especially SDH, VHL, and FH germline variants (cluster 1 tumors), predominantly secrete NE and often has higher maximal standardized uptake values of tumors on18F-FDG PET/CT1. Therefore, 18F-FDG PET/CT scans of these NE-secreting PPGLs should also reveal higher BAT activity. Because BAT activation is also associated with cancer-induced cachexia and thus poor outcomes 2, BAT activation in PPGLs could also indicate aggressive tumor behavior. To study the relationship between BAT activation detected on 18F-FDG PET/CT and the clinical behavior of PPGLs, we performed a retrospective study of 343 patients with genetically characterized and histopathologically confirmed PPGLs who underwent 18F-FDG PET/CT imaging for disease surveillance between 2013 and 2017. After excluding patients with only post-operative PET scans and those with normal serum catecholamines and/or metanephrines, 205 patients were included in the final analysis. BAT activation was observed in 16 patients (7.8%; 28±17y; 10F/6M, 23.4±4.2 kg/m2). Hereditary PPGLs were present in 12/16 patients of which, 10 had cluster 1 variants (SDHx, n=7; HIF2A, n=2; VHL, n=1), 2 had cluster 2 variants (NF1, n=2), and 4 had sporadic PPGL. Elevated plasma biomarkers were as follows: epinephrine (n=0/16); metanephrine (n=2/16); NE (n=11/16); normetanephrine (n=16/16); and dopamine (n=8/16). A matched control group of 36 PPGL patients without detectable BAT activation (34±13y, 21F/15M,23.9±2.5 kg/m2, 12/36 SDHx, p=0.47) revealed a significantly lower mortality rate (n=2/36 vs n=4/16; p=0.043). All deaths in the BAT activation group were found in patients with SDHx variants compared to sporadic PPGL patients in the control group. The development of metastasis was similar in both groups (n=10/16, 62.5% vs. n=27/36, 75%; p=0.36). In conclusion, cluster 1 PPGLs are more likely to be associated with BAT activation. We show for the first time that particularly the combination of an SDHx mutation and BAT activation is associated with a higher mortality. Further investigation is necessary to establish the mechanistic connection between PPGLs, especially those with SDHx mutations, BAT activation, and poorer prognosis. References: 1-Martucci VL, Pacak K. Pheochromocytoma and paraganglioma: diagnosis, genetics, management, and treatment. Current problems in cancer. 2014;38(1):7-41. 2-Petruzzelli M, Schweiger M, Schreiber R, et al. A switch from white to brown fat increases energy expenditure in cancer-associated cachexia. Cell metabolism. 2014;20(3):433-447.
Abstract A Computational Filter (CF) that employs a sample calculation functional block is presen... more Abstract A Computational Filter (CF) that employs a sample calculation functional block is presented. CF significantly reduces the hardware requirements to realize an interpolation filter2. The Computational Filter is compared with advanced Finite Impulse Response (CFIR). CFIR programmable filter is implemented using a Computation Sharing Multiplication (CSHM) technique to optimize the conventional design. The proposed CF significantly reduces the implementation area as compared to CFIR. The maximum average error for wide range of interpolation factors from 8 to 256 is 2.59% for CF and 0.02% for CFIR. Xilinx Virtex5 FPGA XC5VTX240T device is used to compare the proposed design and the advanced CFIR for interpolation factor of 8, 16, 32, and 64. The Computational Filter average reduction in hardware implementation is 78.8%, 89.5%, 94.5%, and 97.1% for interpolation factor of 8, 16, 32, and 64, respectively. The maximum operating frequency for the CFIR is 1 MHz. The maximum operating frequency is 0.92 MHz, 0.57 MHz, 0.32 MHz, and 0.2 MHz for interpolation factor of 8, 16, 32, and 64, respectively.
The purpose of this study was to prospectively use a whole-heart three-dimensional (3D) coronary ... more The purpose of this study was to prospectively use a whole-heart three-dimensional (3D) coronary magnetic resonance (MR) angiography technique specifically adapted for use at 3 T and a parallel imaging technique (sensitivity encoding) to evaluate coronary arterial anomalies and variants (CAAV). This HIPAA-compliant study was approved by the local institutional review board, and informed consent was obtained from all participants. Twenty-two participants (11 men, 11 women; age range, 18-62 years) were included. Ten participants were healthy volunteers, whereas 12 participants were patients suspected of having CAAV. Coronary MR angiography was performed with a 3-T MR imager. A 3D free-breathing navigator-gated and vector electrocardiographically-gated segmented k-space gradient-echo sequence with adiabatic T2 preparation pulse and parallel imaging (sensitivity encoding) was used. Whole-heart acquisitions (repetition time msec/echo time msec, 4/1.35; 20 degrees flip angle; 1 x 1 x 2-mm acquired voxel size) lasted 10-12 minutes. Mean examination time was 41 minutes +/- 14 (standard deviation). Findings included aneurysms, ectasia, arteriovenous fistulas, and anomalous origins. The 3D whole-heart acquisitions developed for use with 3 T are feasible for use in the assessment of CAAV.
Abstract Brown adipose tissue (BAT) activation after cold exposure and its subsequent detection v... more Abstract Brown adipose tissue (BAT) activation after cold exposure and its subsequent detection via18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is mediated through norepinephrine (NE) induced β3-adrenoceptor activation. Pheochromocytoma/paragangliomas (PPGLs), especially SDH, VHL, and FH germline variants (cluster 1 tumors), predominantly secrete NE and often has higher maximal standardized uptake values of tumors on18F-FDG PET/CT1. Therefore, 18F-FDG PET/CT scans of these NE-secreting PPGLs should also reveal higher BAT activity. Because BAT activation is also associated with cancer-induced cachexia and thus poor outcomes 2, BAT activation in PPGLs could also indicate aggressive tumor behavior. To study the relationship between BAT activation detected on 18F-FDG PET/CT and the clinical behavior of PPGLs, we performed a retrospective study of 343 patients with genetically characterized and histopathologically confirmed PPGLs who underwent 18F-FDG PET/CT imaging for disease surveillance between 2013 and 2017. After excluding patients with only post-operative PET scans and those with normal serum catecholamines and/or metanephrines, 205 patients were included in the final analysis. BAT activation was observed in 16 patients (7.8%; 28±17y; 10F/6M, 23.4±4.2 kg/m2). Hereditary PPGLs were present in 12/16 patients of which, 10 had cluster 1 variants (SDHx, n=7; HIF2A, n=2; VHL, n=1), 2 had cluster 2 variants (NF1, n=2), and 4 had sporadic PPGL. Elevated plasma biomarkers were as follows: epinephrine (n=0/16); metanephrine (n=2/16); NE (n=11/16); normetanephrine (n=16/16); and dopamine (n=8/16). A matched control group of 36 PPGL patients without detectable BAT activation (34±13y, 21F/15M,23.9±2.5 kg/m2, 12/36 SDHx, p=0.47) revealed a significantly lower mortality rate (n=2/36 vs n=4/16; p=0.043). All deaths in the BAT activation group were found in patients with SDHx variants compared to sporadic PPGL patients in the control group. The development of metastasis was similar in both groups (n=10/16, 62.5% vs. n=27/36, 75%; p=0.36). In conclusion, cluster 1 PPGLs are more likely to be associated with BAT activation. We show for the first time that particularly the combination of an SDHx mutation and BAT activation is associated with a higher mortality. Further investigation is necessary to establish the mechanistic connection between PPGLs, especially those with SDHx mutations, BAT activation, and poorer prognosis. References: 1-Martucci VL, Pacak K. Pheochromocytoma and paraganglioma: diagnosis, genetics, management, and treatment. Current problems in cancer. 2014;38(1):7-41. 2-Petruzzelli M, Schweiger M, Schreiber R, et al. A switch from white to brown fat increases energy expenditure in cancer-associated cachexia. Cell metabolism. 2014;20(3):433-447.
Abstract A Computational Filter (CF) that employs a sample calculation functional block is presen... more Abstract A Computational Filter (CF) that employs a sample calculation functional block is presented. CF significantly reduces the hardware requirements to realize an interpolation filter2. The Computational Filter is compared with advanced Finite Impulse Response (CFIR). CFIR programmable filter is implemented using a Computation Sharing Multiplication (CSHM) technique to optimize the conventional design. The proposed CF significantly reduces the implementation area as compared to CFIR. The maximum average error for wide range of interpolation factors from 8 to 256 is 2.59% for CF and 0.02% for CFIR. Xilinx Virtex5 FPGA XC5VTX240T device is used to compare the proposed design and the advanced CFIR for interpolation factor of 8, 16, 32, and 64. The Computational Filter average reduction in hardware implementation is 78.8%, 89.5%, 94.5%, and 97.1% for interpolation factor of 8, 16, 32, and 64, respectively. The maximum operating frequency for the CFIR is 1 MHz. The maximum operating frequency is 0.92 MHz, 0.57 MHz, 0.32 MHz, and 0.2 MHz for interpolation factor of 8, 16, 32, and 64, respectively.
The purpose of this study was to prospectively use a whole-heart three-dimensional (3D) coronary ... more The purpose of this study was to prospectively use a whole-heart three-dimensional (3D) coronary magnetic resonance (MR) angiography technique specifically adapted for use at 3 T and a parallel imaging technique (sensitivity encoding) to evaluate coronary arterial anomalies and variants (CAAV). This HIPAA-compliant study was approved by the local institutional review board, and informed consent was obtained from all participants. Twenty-two participants (11 men, 11 women; age range, 18-62 years) were included. Ten participants were healthy volunteers, whereas 12 participants were patients suspected of having CAAV. Coronary MR angiography was performed with a 3-T MR imager. A 3D free-breathing navigator-gated and vector electrocardiographically-gated segmented k-space gradient-echo sequence with adiabatic T2 preparation pulse and parallel imaging (sensitivity encoding) was used. Whole-heart acquisitions (repetition time msec/echo time msec, 4/1.35; 20 degrees flip angle; 1 x 1 x 2-mm acquired voxel size) lasted 10-12 minutes. Mean examination time was 41 minutes +/- 14 (standard deviation). Findings included aneurysms, ectasia, arteriovenous fistulas, and anomalous origins. The 3D whole-heart acquisitions developed for use with 3 T are feasible for use in the assessment of CAAV.
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