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Proton density fat fraction

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https://www.readbyqxmd.com/read/27911262/magnetic-resonance-elastography-vs-transient-elastography-in-detection-of-fibrosis-and-noninvasive-measurement-of-steatosis-in-patients-with-biopsy-proven-nonalcoholic-fatty-liver-disease
#1
Charlie C Park, Phirum Nguyen, Carolyn Hernandez, Ricki Bettencourt, Kimberly Ramirez, Lynda Fortney, Jonathan Hooker, Ethan Sy, Mosab H Alquiraish, Mark A Valasek, Emily Rizo, Lisa Richards, David Brenner, Claude B Sirlin, Rohit Loomba
BACKGROUND & AIMS: Magnetic-resonance-imaging (MRI) techniques and ultrasound-based transient elastography (TE) can be used in noninvasive diagnosis of fibrosis and steatosis in patients with nonalcoholic fatty liver disease (NAFLD). We performed a prospective study to compare the performance of magnetic resonance elastography (MRE) vs TE for in diagnosis of fibrosis, and MRI-based proton density fat fraction (MRI-PDFF) analysis vs TE-based controlled attenuation parameter (CAP) for diagnosis of steatosis in patients undergoing biopsy to assess NAFLD...
October 27, 2016: Gastroenterology
https://www.readbyqxmd.com/read/27851874/adc-quantification-of-the-vertebral-bone-marrow-water-component-removing-the-confounding-effect-of-residual-fat
#2
Michael Dieckmeyer, Stefan Ruschke, Holger Eggers, Hendrik Kooijman, Ernst J Rummeny, Jan S Kirschke, Thomas Baum, Dimitrios C Karampinos
PURPOSE: To remove the confounding effect of unsuppressed fat on the imaging-based apparent diffusion coefficient (ADC) of the vertebral bone marrow water component when using spectrally selective fat suppression and to compare and validate the proposed quantification strategy against diffusion-weighted magnetic resonance spectroscopy (DW-MRS). METHODS: Twelve subjects underwent diffusion-weighted imaging (DWI) and DW-MRS of the vertebral bone marrow. A theoretical model was developed to take into account and correct the effects of residual fat on ADC, incorporating additional measurements for proton density fat fraction (PDFF) and water T2 (T2w)...
November 8, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/27824667/proton-magnetic-resonance-spectroscopy-detected-changes-of-marrow-fat-content-in-a-rabbit-model-of-osteoporosis-treated-with-epigallocatechin-3-gallate
#3
Yin Liu, Sijie Wu, Rongrong Cui, Qian Chan, Shengwang Zhang, Yunjie Liao, Can Huang
OBJECTIVE: The aim of this study was to longitudinally evaluate the changes in marrow fat content of ovariectomized (OVX) rabbits treated with epigallocatechin-3-gallate (EGCG) using proton magnetic resonance spectroscopy (H-MRS). METHODS: Thirty-six female New Zealand rabbits were equally divided into sham operation, OVX controls, and OVX treated with EGCG (intraperitoneally, 1.8 mg/kg) for 5 months. Marrow fat fraction by H-MRS and bone density by peripheral quantitative computed tomography were determined at 0, 3, and 5 months...
November 7, 2016: Journal of Computer Assisted Tomography
https://www.readbyqxmd.com/read/27818597/comparison-of-magnetic-resonance-spectroscopy-proton-density-fat-fraction-and-histological-analysis-in-the-quantification-of-liver-steatosis-in-children-and-adolescents
#4
Michele Di Martino, Lucia Pacifico, Mario Bezzi, Rossella Di Miscio, Beatrice Sacconi, Claudio Chiesa, Carlo Catalano
AIM: To establish a threshold value for liver fat content between healthy children and those with non-alcoholic fatty liver disease (NAFLD) by using magnetic resonance imaging (MRI), with liver biopsy serving as a reference standard. METHODS: The study was approved by the local ethics committee, and written informed consent was obtained from all participants and their legal guardians before the study began. Twenty-seven children with NAFLD underwent liver biopsy to assess the presence of nonalcoholic steatohepatitis...
October 21, 2016: World Journal of Gastroenterology: WJG
https://www.readbyqxmd.com/read/27797100/correction-of-phase-errors-in-quantitative-water-fat-imaging-using-a-monopolar-time-interleaved-multi-echo-gradient-echo-sequence
#5
Stefan Ruschke, Holger Eggers, Hendrik Kooijman, Maximilian N Diefenbach, Thomas Baum, Axel Haase, Ernst J Rummeny, Houchun H Hu, Dimitrios C Karampinos
PURPOSE: To propose a phase error correction scheme for monopolar time-interleaved multi-echo gradient echo water-fat imaging that allows accurate and robust complex-based quantification of the proton density fat fraction (PDFF). METHODS: A three-step phase correction scheme is proposed to address a) a phase term induced by echo misalignments that can be measured with a reference scan using reversed readout polarity, b) a phase term induced by the concomitant gradient field that can be predicted from the gradient waveforms, and c) a phase offset between time-interleaved echo trains...
October 31, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/27783208/non-invasive-diagnosis-of-hepatic-steatosis
#6
REVIEW
Christiane Stern, Laurent Castera
Non-invasive diagnosis and quantification of hepatic steatosis rely on two different but complementary approaches: biomarkers or imaging techniques, either ultrasound-based such as liver ultrasonography and controlled attenuation parameter (CAP), or computed tomography (CT) and magnetic resonance imaging (MRI). Scores for the detection of steatosis have not gained much popularity in clinical practice so far. CAP, using the M probe, is the most promising technique but needs to be implemented with the XL probe and compared to ultrasound that, despite its limitations, remains the most widely used method...
October 25, 2016: Hepatology International
https://www.readbyqxmd.com/read/27726414/accuracy-of-liver-fat-quantification-with-advanced-ct-mri-and-ultrasound-techniques-prospective-comparison-with-mr-spectroscopy
#7
Harald Kramer, Perry J Pickhardt, Mark A Kliewer, Diego Hernando, Guang-Hong Chen, James A Zagzebski, Scott B Reeder
OBJECTIVE: The purpose of this study was to prospectively evaluate the accuracy of proton-density fat-fraction, single- and dual-energy CT (SECT and DECT), gray-scale ultrasound (US), and US shear-wave elastography (US-SWE) in the quantification of hepatic steatosis with MR spectroscopy (MRS) as the reference standard. SUBJECTS AND METHODS: Fifty adults who did not have symptoms (23 men, 27 women; mean age, 57 ± 5 years; body mass index, 27 ± 5) underwent liver imaging with un-enhanced SECT, DECT, gray-scale US, US-SWE, proton-density fat-fraction MRI, and MRS for this prospective trial...
October 11, 2016: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/27688063/agreement-between-region-of-interest-and-parametric-map-based-hepatic-proton-density-fat-fraction-estimation-in-adults-with-chronic-liver-disease
#8
Paul M Manning, Gavin Hamilton, Kang Wang, Chulhyun Park, Jonathan C Hooker, Tanya Wolfson, Anthony Gamst, William M Haufe, Alex N Schlein, Michael S Middleton, Claude B Sirlin
PURPOSE: To compare agreement between region-of-interest (ROI)- and parametric map-based methods of hepatic proton density fat fraction (PDFF) estimation in adults with known or suspected hepatic steatosis secondary to chronic liver disease over a range of imaging and analysis conditions. MATERIALS AND METHODS: In this IRB approved HIPAA compliant prospective single-site study, 31 adults with chronic liver disease undergoing clinical gadoxetic acid-enhanced liver magnetic resonance imaging at 3 T were recruited...
September 29, 2016: Abdominal Radiology
https://www.readbyqxmd.com/read/27650137/the-effects-of-concomitant-gradients-on-chemical-shift-encoded-mri
#9
Timothy J Colgan, Diego Hernando, Samir D Sharma, Scott B Reeder
PURPOSE: The purpose of this work was to characterize the effects of concomitant gradients (CGs) on chemical shift encoded (CSE)-based estimation of B0 field map, proton density fat fraction (PDFF), and R2*. THEORY: A theoretical framework was used to determine the effects of CG-induced phase errors on CSE-MRI data. METHODS: Simulations, phantom experiments, and in vivo experiments were conducted at 3 Tesla to assess the effects of CGs on quantitative CSE-MRI techniques...
September 21, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/27582882/association-of-noninvasive-quantitative-decline-in-liver-fat-content-on-mri-with-histologic-response-in-nonalcoholic-steatohepatitis
#10
Janki Patel, Ricki Bettencourt, Jeffrey Cui, Joanie Salotti, Jonathan Hooker, Archana Bhatt, Carolyn Hernandez, Phirum Nguyen, Hamed Aryafar, Mark Valasek, William Haufe, Catherine Hooker, Lisa Richards, Claude B Sirlin, Rohit Loomba
BACKGROUND: Magnetic resonance imaging-estimated proton-density-fat-fraction (MRI-PDFF) has been shown to be a noninvasive, accurate and reproducible imaging-based biomarker for assessing steatosis and treatment response in nonalcoholic steatohepatitis (NASH) clinical trials. However, there are no data on the magnitude of MRI-PDFF reduction corresponding to histologic response in the setting of a NASH clinical trial. The aim of this study was to quantitatively compare the magnitude of MRI-PDFF reduction between histologic responders versus histologic nonresponders in NASH patients...
September 2016: Therapeutic Advances in Gastroenterology
https://www.readbyqxmd.com/read/27541685/reduction-of-longitudinal-vertebral-blood-perfusion-and-its-likely-causes-a-quantitative-dynamic-contrast-enhanced-mr-imaging-study-of-a-rat-osteoporosis-model
#11
Jingqi Zhu, Lin Zhang, Xing Wu, Zuogang Xiong, Yuyou Qiu, Ting Hua, Guangyu Tang
Purpose To determine the longitudinal relationships among lumbar vertebral blood perfusion, bone mass, and marrow adipose tissue in a rat osteoporosis model after ovariectomy by using quantitative dynamic contrast agent-enhanced (DCE) magnetic resonance (MR) imaging, microcomputed tomography (micro-CT), and proton MR spectroscopy. Materials and Methods In this animal review committee-approved study, lumbar vertebrae were evaluated through MR spectroscopy, quantitative DCE MR imaging, micro-CT, and histopathologic analysis, and blood was examined at 0, 2, 6, 10, 14, 18, and 24 weeks after ovariectomy consisting of exposure of the ovaries but no excision (n = 35) or sham operation, defined as exposure of the ovaries but no excision (n = 35)...
August 19, 2016: Radiology
https://www.readbyqxmd.com/read/27405703/quantification-of-liver-fat-in-the-presence-of-iron-overload
#12
Debra E Horng, Diego Hernando, Scott B Reeder
PURPOSE: To evaluate the accuracy of R2* models (1/T2 * = R2*) for chemical shift-encoded magnetic resonance imaging (CSE-MRI)-based proton density fat-fraction (PDFF) quantification in patients with fatty liver and iron overload, using MR spectroscopy (MRS) as the reference standard. MATERIALS AND METHODS: Two Monte Carlo simulations were implemented to compare the root-mean-squared-error (RMSE) performance of single-R2* and dual-R2* correction in a theoretical liver environment with high iron...
July 13, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27341545/comparison-of-chemical-shift-encoded-water-fat-mri-and-mr-spectroscopy-in-quantification-of-marrow-fat-in-postmenopausal-females
#13
Guanwu Li, Zheng Xu, Hao Gu, Xuefeng Li, Wei Yuan, Shixin Chang, Jingzheng Fan, Horea Calimente, Jiani Hu
PURPOSE: To validate a chemical shift-encoded (CSE) water-fat imaging for quantifying marrow fat fraction (FF), using proton magnetic resonance spectroscopy (MRS) as reference. MATERIALS AND METHODS: Multiecho T2 -corrected MRS and CSE imaging with eight-echo gradient-echo acquisitions at 3T were performed to calculate marrow FF in 83 subjects, including 41 with normal bone mineral density (BMD), 26 with osteopenia, and 16 with osteoporosis (based on DXA). Eight participants were scanned three times with repositioning to assess the repeatability of CSE FF map measurements...
June 24, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27315352/shared-genetic-effects-between-hepatic-steatosis-and-fibrosis-a-prospective-twin-study
#14
Jeffrey Cui, Chi-Hua Chen, Min-Tzu Lo, Nicholas Schork, Ricki Bettencourt, Monica P Gonzalez, Archana Bhatt, Jonathan Hooker, Katherine Shaffer, Karen E Nelson, Michelle T Long, David A Brenner, Claude B Sirlin, Rohit Loomba, For The Genetics Of Nafld In Twins Consortium
: Nonalcoholic fatty liver disease is associated with metabolic risk factors including hypertension and dyslipidemia and may progress to liver fibrosis. Studies have shown that hepatic steatosis and fibrosis are heritable, but whether they have a significant shared gene effect is unknown. This study examined the shared gene effects between hepatic steatosis and fibrosis and their associations with metabolic risk factors. This was a cross-sectional analysis of a prospective cohort of well-characterized, community-dwelling twins (45 monozygotic, 20 dizygotic twin pairs, 130 total subjects) from southern California...
November 2016: Hepatology: Official Journal of the American Association for the Study of Liver Diseases
https://www.readbyqxmd.com/read/27251889/in-vivo-magnetic-resonance-microscopy-and-hypothermic-anaesthesia-of-a-disease-model-in-medaka
#15
Tomohiro Ueno, Hirokazu Suzuki, Masahiro Hiraishi, Hideaki Amano, Hidenao Fukuyama, Naozo Sugimoto
In medical and pharmacological research, various human disease models in small fish, such as medaka (Oryzias latipes), have been created. To investigate these disease models noninvasively, magnetic resonance imaging (MRI) is suitable because these small fish are no longer transparent as adults. However, their small body size requires a high spatial resolution, and a water pool should be avoided to maximize the strength of MRI. We developed in vivo magnetic resonance microscopy (MR microscopy) without a water pool by combining hypothermic anaesthesia and a 14...
2016: Scientific Reports
https://www.readbyqxmd.com/read/27226976/fat-water-mri-of-a-diet-induced-obesity-mouse-model-at-15-2t
#16
Henry H Ong, Corey D Webb, Marnie L Gruen, Alyssa H Hasty, John C Gore, E Brian Welch
Quantitative fat-water MRI (FWMRI) methods provide valuable information about the distribution, volume, and composition of adipose tissue (AT). Ultra high field FWMRI of animal models may have the potential to provide insights into the progression of obesity and its comorbidities. Here, we present quantitative FWMRI with all known confounder corrections on a 15.2T preclinical scanner for noninvasive in vivo monitoring of an established diet-induced obesity mouse model. Male C57BL/6J mice were placed on a low-fat (LFD) or a high-fat diet (HFD)...
April 2016: Journal of Medical Imaging
https://www.readbyqxmd.com/read/27197806/quantification-of-liver-proton-density-fat-fraction-in-7-1t-preclinical-mr-systems-impact-of-the-fitting-technique
#17
Christoph Mahlke, Diego Hernando, Christina Jahn, Antonio Cigliano, Till Ittermann, Anne Mössler, Marie-Luise Kromrey, Grazyna Domaska, Scott B Reeder, Jens-Peter Kühn
PURPOSE: To investigate the feasibility of estimating the proton-density fat fraction (PDFF) using a 7.1T magnetic resonance imaging (MRI) system and to compare the accuracy of liver fat quantification using different fitting approaches. MATERIALS AND METHODS: Fourteen leptin-deficient ob/ob mice and eight intact controls were examined in a 7.1T animal scanner using a 3D six-echo chemical shift-encoded pulse sequence. Confounder-corrected PDFF was calculated using magnitude (magnitude data alone) and combined fitting (complex and magnitude data)...
December 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27151177/sitagliptin-vs-placebo-for-non-alcoholic-fatty-liver-disease-a-randomized-controlled-trial
#18
Jeffrey Cui, Len Philo, Phirum Nguyen, Heather Hofflich, Carolyn Hernandez, Ricki Bettencourt, Lisa Richards, Joanie Salotti, Archana Bhatt, Jonathan Hooker, William Haufe, Catherine Hooker, David A Brenner, Claude B Sirlin, Rohit Loomba
BACKGROUND & AIMS: Uncontrolled studies show sitagliptin, an oral DPP-4 inhibitor, may improve alanine aminotransferase and liver histology in non-alcoholic fatty liver disease (NAFLD) patients. We aimed to compare sitagliptin vs. the efficacy of a placebo in reducing liver fat measured by MRI-derived proton density-fat fraction (MRI-PDFF). METHODS: This randomized, double-blind, allocation-concealed, placebo-controlled trial included 50 NAFLD patients with prediabetes or early diabetes randomized to sitagliptin orally 100mg/day or placebo for 24weeks...
August 2016: Journal of Hepatology
https://www.readbyqxmd.com/read/27136334/minimum-field-strength-simulator-for-proton-density-weighted-mri
#19
Ziyue Wu, Weiyi Chen, Krishna S Nayak
OBJECTIVE: To develop and evaluate a framework for simulating low-field proton-density weighted MRI acquisitions based on high-field acquisitions, which could be used to predict the minimum B0 field strength requirements for MRI techniques. This framework would be particularly useful in the evaluation of de-noising and constrained reconstruction techniques. MATERIALS AND METHODS: Given MRI raw data, lower field MRI acquisitions can be simulated based on the signal and noise scaling with field strength...
2016: PloS One
https://www.readbyqxmd.com/read/27128911/definitions-of-normal-liver-fat-and-the-association-of-insulin-sensitivity-with-acquired-and-genetic-nafld-a-systematic-review
#20
REVIEW
Elina M Petäjä, Hannele Yki-Järvinen
Non-alcoholic fatty liver disease (NAFLD) covers a spectrum of disease ranging from simple steatosis (NAFL) to non-alcoholic steatohepatitis (NASH) and fibrosis. "Obese/Metabolic NAFLD" is closely associated with obesity and insulin resistance and therefore predisposes to type 2 diabetes and cardiovascular disease. NAFLD can also be caused by common genetic variants, the patatin-like phospholipase domain-containing 3 (PNPLA3) or the transmembrane 6 superfamily member 2 (TM6SF2). Since NAFL, irrespective of its cause, can progress to NASH and liver fibrosis, its definition is of interest...
2016: International Journal of Molecular Sciences
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