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Proton density fat fraction

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https://www.readbyqxmd.com/read/29130539/sources-of-systematic-error-in-proton-density-fat-fraction-pdff-quantification-in-the-liver-evaluated-from-magnitude-images-with-different-numbers-of-echoes
#1
Mark Bydder, Gavin Hamilton, Ludovic de Rochefort, Ajinkya Desai, Elhamy R Heba, Rohit Loomba, Jeffrey B Schwimmer, Nikolaus M Szeverenyi, Claude B Sirlin
The purpose of this work was to investigate sources of bias in magnetic resonance imaging (MRI) liver fat quantification that lead to a dependence of the proton density fat fraction (PDFF) on the number of echoes. This was a retrospective analysis of liver MRI data from 463 subjects. The magnitude signal variation with TE from spoiled gradient echo images was curve fitted to estimate the PDFF using a model that included monoexponential R2 * decay and a multi-peak fat spectrum. Additional corrections for non-exponential decay (Gaussian), bi-exponential decay, degree of fat saturation, water frequency shift and noise bias were introduced...
November 12, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/29108123/optimal-threshold-of-controlled-attenuation-parameter-with-mri-pdff-as-the-gold-standard-for-the-detection-of-hepatic-steatosis
#2
Cyrielle Caussy, Mosab H Alquiraish, Phirum Nguyen, Carolyn Hernandez, Sandra Cepin, Lynda E Fortney, Veeral Ajmera, Ricki Bettencourt, Summer Collier, Jonathan Hooker, Ethan Sy, Emily Rizo, Lisa Richards, Claude B Sirlin, Rohit Loomba
The optimal threshold of controlled attenuation parameter (CAP) for the detection of hepatic steatosis using both M and XL probe is unknown in nonalcoholic fatty liver disease (NAFLD). Magnetic resonance imaging proton-density-fat-fraction (MRI-PDFF) is an accurate and precise method to detect presence of hepatic steatosis and is better than CAP. Thus, the aim of this study was to evaluate the diagnostic accuracy and the optimal threshold of CAP for the detection of hepatic steatosis as defined by MRI-PDFF ≥ 5%...
November 6, 2017: Hepatology: Official Journal of the American Association for the Study of Liver Diseases
https://www.readbyqxmd.com/read/29089822/impact-of-liver-fibrosis-and-fatty-liver-on-t1rho-measurements-a-prospective-study
#3
Shuangshuang Xie, Qing Li, Yue Cheng, Yu Zhang, Zhizheng Zhuo, Guiming Zhao, Wen Shen
OBJECTIVE: To investigate the liver T1rho values for detecting fibrosis, and the potential impact of fatty liver on T1rho measurements. MATERIALS AND METHODS: This study included 18 healthy subjects, 18 patients with fatty liver, and 18 patients with liver fibrosis, who underwent T1rho MRI and mDIXON collections. Liver T1rho, proton density fat fraction (PDFF) and T2* values were measured and compared among the three groups. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the T1rho values for detecting liver fibrosis...
November 2017: Korean Journal of Radiology: Official Journal of the Korean Radiological Society
https://www.readbyqxmd.com/read/29080242/can-negligible-hepatic-steatosis-determined-by-mri-proton-density-fat-fraction-obviate-the-need-for-liver-biopsy-in-potential-liver-donors
#4
Janakan Satkunasingham, Hooman Hosseini Nik, Sandra Fischer, Ravi Menezes, Nazia Selzner, Mark Cattral, David Grant, Kartik Jhaveri
PURPOSE: To determine whether magnetic resonance proton density fat fraction (MR-PDFF) estimate of negligible hepatic fat percentage (<5%) can exclude significant hepatic steatosis (≥ 10%) in living liver donor candidates obviating the need for liver biopsy. To perform intra-individual comparisons between MR-PDFF techniques for hepatic steatosis quantification. MATERIALS AND METHODS: In an ethics approved retrospective study, 144 liver donor candidates with MR spectroscopy (MRS) and six-echo Dixon MRI between 2013 and 2015 were included...
October 28, 2017: Liver Transplantation
https://www.readbyqxmd.com/read/29063256/sciatic-neurosteatosis-relationship-with-age-gender-obesity-and-height
#5
Shayna Ratner, Raamis Khwaja, Lihua Zhang, Yin Xi, Riham Dessouky, Craig Rubin, Avneesh Chhabra
AIM: To evaluate inter-reader performance for cross-sectional area and fat quantification of bilateral sciatic nerves on MRI and assess correlations with anthropometrics. METHODS: In this IRB-approved, HIPPA-compliant study, three readers performed a cross-sectional analysis of 3T lumbosacral plexus MRIs over an 18-month period. Image slices were evaluated at two levels (A and B). The sciatic nerve was outlined using a free hand region of interest tool on PACS. Proton-density fat fraction (FF) and cross-sectional areas were recorded...
October 23, 2017: European Radiology
https://www.readbyqxmd.com/read/29058029/increased-severity-of-liver-fat-content-and-liver-fibrosis-in-non-alcoholic-fatty-liver-disease-correlate-with-epicardial-fat-volume-in-type-2-diabetes-a-prospective-study
#6
Sharon S Brouha, Phirum Nguyen, Ricki Bettencourt, Claude B Sirlin, Rohit Loomba
OBJECTIVES: To determine whether severity of non-alcoholic fatty liver disease (NAFLD) and liver fibrosis quantitatively assessed in individuals with diabetes mellitus (DM)-2 correlate with increased coronary heart disease (CHD) risk using non-invasive markers. METHODS: We conducted a single-centre, prospective, cross-sectional study in 100 consecutive diabetic individuals without known CHD recruited between March 2013 and September 2014. History, physical examination, serum markers, cardiac computed tomography (CT), magnetic resonance (MR) imaging-estimated proton density fat fraction (PDFF) and MR elastography (MRE) were obtained for 95 participants...
October 20, 2017: European Radiology
https://www.readbyqxmd.com/read/29028128/diagnostic-accuracy-of-magnetic-resonance-imaging-hepatic-proton-density-fat-fraction-in-pediatric-nonalcoholic-fatty-liver-disease
#7
Michael S Middleton, Mark L Van Natta, Elhamy R Heba, Adina Alazraki, Andrew T Trout, Prakash Masand, Elizabeth M Brunt, David E Kleiner, Edward Doo, James Tonascia, Joel E Lavine, Wei Shen, Gavin Hamilton, Jeffrey B Schwimmer, Claude B Sirlin
We assessed the performance of magnetic resonance imaging (MRI) proton density fat fraction (PDFF) in children to stratify hepatic steatosis grade before and after treatment in the Cysteamine Bitartrate Delayed-Release for the Treatment of Nonalcoholic Fatty Liver Disease in Children (CyNCh) trial, using centrally-scored histology as reference. Participants had multi-echo 1.5T or 3T MRI on scanners from three manufacturers. Of 169 enrolled children, 110 (65%) and 83 (49%) had MRI and liver biopsy at baseline and at end-of-treatment (EOT; 52-weeks), respectively...
October 13, 2017: Hepatology: Official Journal of the American Association for the Study of Liver Diseases
https://www.readbyqxmd.com/read/29022777/feasibility-of-modified-dixon-mri-techniques-for-hepatic-fat-quantification-in-hepatic-disorders-validation-with-mrs-and-histology
#8
Bo-Kyeong Kang, Mimi Kim, Soon-Young Song, Dae Won Jun, Kiseok Jang
OBJECTIVE: To assess the feasibility of proton density fat fraction (PDFF) MRI for estimating hepatic fat fraction with magnetic resonance spectroscopy (MRS) and histology as references and to investigate intrahepatic fat distribution and variability. METHODS: Between November 2014 and September 2015, 85 adults (48 males, 47 females) who underwent MRI-PDFF (n = 139), MRS-PDFF (n = 49) and liver biopsy (n = 29) were enrolled in this study. Data were compared using linear regression...
November 8, 2017: British Journal of Radiology
https://www.readbyqxmd.com/read/28931343/impact-of-bowel-gas-and-body-outline-variations-on-total-accumulated-dose-with-intensity-modulated-proton-therapy-in-locally-advanced-cervical-cancer-patients
#9
Thomas Berger, Jørgen Breede Baltzer Petersen, Jacob Christian Lindegaard, Lars Ulrik Fokdal, Kari Tanderup
INTRODUCTION: Density changes occurring during fractionated radiotherapy in the pelvic region may degrade proton dose distributions. The aim of the study was to quantify the dosimetric impact of gas cavities and body outline variations. MATERIAL AND METHODS: Seven patients with locally advanced cervical cancer (LACC) were analyzed through a total of 175 daily cone beam computed tomography (CBCT) scans. Four-beams intensity-modulated proton therapy (IMPT) dose plans were generated targeting the internal target volume (ITV) composed of: primary tumor, elective and pathological nodes...
November 2017: Acta Oncologica
https://www.readbyqxmd.com/read/28915103/mr-spectroscopy-derived-proton-density-fat-fraction-is-superior-to-controlled-attenuation-parameter-for-detecting-and-grading-hepatic-steatosis
#10
Jurgen Henk Runge, Loek Pieter Smits, Joanne Verheij, Annekatrien Depla, Sjoerd Douwe Kuiken, Bert Cornelis Baak, Aart Johannes Nederveen, Ulrich Beuers, Jaap Stoker
Purpose To prospectively compare the diagnostic accuracy of controlled attenuation parameter (CAP) obtained with transient elastography and proton density fat fraction (PDFF) obtained with proton magnetic resonance (MR) spectroscopy with results of liver biopsy in a cohort of adult patients suspected of having nonalcoholic fatty liver disease (NAFLD). Materials and Methods The institutional review board approved this study. Informed consent was obtained from all patients. The authors evaluated 55 patients suspected of having NAFLD (40 men, 15 women)...
September 15, 2017: Radiology
https://www.readbyqxmd.com/read/28895045/influence-of-gd-eob-dtpa-on-proton-density-fat-fraction-using-the-six-echo-dixon-method-in-3-tesla-magnetic-resonance-imaging
#11
Tatsuya Hayashi, Kei Fukuzawa, Hiroshi Kondo, Hiroshi Onodera, Shuji Toyotaka, Rie Tojo, Shimpei Yano, Masakatsu Tano, Tosiaki Miyati, Jun'ichi Kotoku, Takahide Okamoto, Keiko Toyoda, Hiroshi Oba
The purpose of this study was to evaluate whether disodium gadoxetate (Gd-EOB-DTPA) affects proton density fat fractions (PDFFs) during use of the multiecho Dixon (meDixon) method in phantom and simulation magnetic resonance imaging (MRI) studies at 3 T. Fat-water phantoms comprising vegetable fat-water emulsions with varying fat volume percentages (0, 5, 10, 15, 20, 30, 40, and 50) and Gd-EOB-DTPA concentrations (0 and 0.4 mM) were prepared. Phantoms without Gd-EOB-DTPA were defined as precontrast, and those with Gd-EOB-DTPA were defined as postcontrast...
September 11, 2017: Radiological Physics and Technology
https://www.readbyqxmd.com/read/28894290/association-of-proton-density-fat-fraction-in-adipose-tissue-with-imaging-based-and-anthropometric-obesity-markers-in-adults
#12
D Franz, D Weidlich, F Freitag, C Holzapfel, T Drabsch, T Baum, H Eggers, A Witte, E J Rummeny, H Hauner, D C Karampinos
BACKGROUND/OBJECTIVES: The purpose of this study was to examine the relationship of the proton density fat fraction (PDFF), measured by magnetic resonance imaging (MRI), of supraclavicular and gluteal adipose tissue with subcutaneous and visceral adipose tissue (SAT and VAT) volumes, liver fat fraction and anthropometric obesity markers. The supraclavicular fossa was selected as a typical location where brown adipocytes may be present in humans and the gluteal region was selected as a typical location enclosing primarily white adipocytes...
August 14, 2017: International Journal of Obesity: Journal of the International Association for the Study of Obesity
https://www.readbyqxmd.com/read/28892558/the-ask1-inhibitor-selonsertib-in-patients-with-nonalcoholic-steatohepatitis-a-randomized-phase-2-trial
#13
Rohit Loomba, Eric Lawitz, Parvez S Mantry, Saumya Jayakumar, Stephen H Caldwell, Hays Arnold, Anna Mae Diehl, C Stephen Djedjos, Ling Han, Robert P Myers, G Mani Subramanian, John G McHutchison, Zachary D Goodman, Nezam H Afdhal, Michael R Charlton
Inhibition of apoptosis signal-regulating kinase 1 (ASK1), a serine/threonine kinase, leads to improvement in inflammation and fibrosis in animal models of nonalcoholic steatohepatitis (NASH). We evaluated the safety and efficacy of selonsertib, a selective inhibitor of ASK1, alone or in combination with simtuzumab, in patients with NASH and stage 2 or 3 liver fibrosis. In this multicenter phase 2 trial, 72 patients were randomized to receive 24 weeks of open-label treatment with either 6 or 18 mg of selonsertib orally once daily with or without once-weekly injections of 125 mg of simtuzumab, or simtuzumab alone...
September 11, 2017: Hepatology: Official Journal of the American Association for the Study of Liver Diseases
https://www.readbyqxmd.com/read/28892458/linearity-bias-and-precision-of-hepatic-proton-density-fat-fraction-measurements-by-using-mr-imaging-a-meta-analysis
#14
Takeshi Yokoo, Suraj D Serai, Ali Pirasteh, Mustafa R Bashir, Gavin Hamilton, Diego Hernando, Houchun H Hu, Holger Hetterich, Jens-Peter Kühn, Guido M Kukuk, Rohit Loomba, Michael S Middleton, Nancy A Obuchowski, Ji Soo Song, An Tang, Xinhuai Wu, Scott B Reeder, Claude B Sirlin
Purpose To determine the linearity, bias, and precision of hepatic proton density fat fraction (PDFF) measurements by using magnetic resonance (MR) imaging across different field strengths, imager manufacturers, and reconstruction methods. Materials and Methods This meta-analysis was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A systematic literature search identified studies that evaluated the linearity and/or bias of hepatic PDFF measurements by using MR imaging (hereafter, MR imaging-PDFF) against PDFF measurements by using colocalized MR spectroscopy (hereafter, MR spectroscopy-PDFF) or the precision of MR imaging-PDFF...
September 11, 2017: Radiology
https://www.readbyqxmd.com/read/28842937/optimization-of-region-of-interest-sampling-strategies-for-hepatic-mri-proton-density-fat-fraction-quantification
#15
Cheng William Hong, Tanya Wolfson, Ethan Z Sy, Alexandra N Schlein, Jonathan C Hooker, Soudabeh Fazeli Dehkordy, Gavin Hamilton, Scott B Reeder, Rohit Loomba, Claude B Sirlin
BACKGROUND: Clinical trials utilizing proton density fat fraction (PDFF) as an imaging biomarker for hepatic steatosis have used a laborious region-of-interest (ROI) sampling strategy of placing an ROI in each hepatic segment. PURPOSE: To identify a strategy with the fewest ROIs that consistently achieves close agreement with the nine-ROI strategy. STUDY TYPE: Retrospective secondary analysis of prospectively acquired clinical research data...
August 26, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28816961/estimating-of-hepatic-fat-amount-using-mri-proton-density-fat-fraction-in-a-real-practice-setting
#16
RANDOMIZED CONTROLLED TRIAL
Hyeyoung Lee, Dae Won Jun, Bo-Kyeong Kang, Eunwoo Nam, Misoo Chang, Mimi Kim, Soonyoung Song, Byung Chul Yoon, Hang Lak Lee, Oh Young Lee, Ho Soon Choi, Kang Nyeong Lee
The recently developed magnetic resonance imaging (MRI) proton density fat fraction (PDFF) allows measurement of the fat in all segments of hepatic tissue. However, it is time consuming and inconvenient to measure each segment repeatedly. Moreover, volume of each segment also should be adjusted with arithmetic mean of the selected segments when total amount of liver fat is estimated. Therefore, we try to develop a clinically-relevant and applicable method of estimating hepatic fat in PDFF image.A total of 164 adults were enrolled...
August 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28800087/imaging-features-of-non-alcoholic-fatty-liver-disease-in-children-and-adolescents
#17
REVIEW
Michele Di Martino, Kameliya Koryukova, Mario Bezzi, Carlo Catalano
Non-invasive diagnosis and quantification of liver steatosis is important to overcome limits of liver biopsy, in order to follow up patients during their therapy and to establish a reference standard that can be used in clinical trials and longitudinal studies. Imaging offers several methods in this setting: ultrasound, which is the cheapest technique and easy to perform; magnetic resonance spectroscopy (MRS), which reflects the real content of triglycerides in a specific volume; and proton density fat fraction (PDFF) magnetic resonance, which is a simple method that reflects the distribution of the fat in the whole liver...
August 11, 2017: Children
https://www.readbyqxmd.com/read/28770394/evaluation-of-six-point-modified-dixon-and-magnetic-resonance-spectroscopy-for-fat-quantification-a-fat-water-iron-phantom-study
#18
Kei Fukuzawa, Tatsuya Hayashi, Junji Takahashi, Chiharu Yoshihara, Masakatsu Tano, Jun'ichi Kotoku, Satoshi Saitoh
This study aimed to evaluate (1) the agreement between the true fat fraction (FF) and proton density FF (PDFF) measured using a six-echo modified Dixon (6mDixon) and magnetic resonance spectroscopy (MRS) and (2) the influence of fat on T2* values. The study was performed using phantoms of varying fat and iron content. Point-resolved spectroscopy (PRESS) and stimulated echo acquisition mode (STEAM) with single-echo (S) and multiecho (M) (PRESS-S, PRESS-M, STEAM-S, and STEAM-M) were used for MRS. In phantoms without iron, the agreement between the true FF and measured PDFF was tested using Bland-Altman analysis...
August 2, 2017: Radiological Physics and Technology
https://www.readbyqxmd.com/read/28705058/standardized-approach-for-roi-based-measurements-of-proton-density-fat-fraction-and-r2-in-the-liver
#19
Camilo A Campo, Diego Hernando, Tilman Schubert, Candice A Bookwalter, Andrew J Van Pay, Scott B Reeder
OBJECTIVE: The purpose of this study was to evaluate the reproducibility (interreviewer agreement) and repeatability (intrareviewer agreement) of ROI sampling strategies to measure chemical shift-encoded (CSE) MRI-based liver proton density fat fraction (PDFF) and R2* (1 / T2*). A secondary purpose was to standardize ROI-based liver PDFF and R2* measurements by providing a compromise between measurement reproducibility and repeatability and time burden for image analysts. MATERIALS AND METHODS: CSE data from two cohorts were retrospectively analyzed...
September 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/28698004/the-effect-of-radiotherapy-on-fat-content-and-fatty-acids-in-myxoid-liposarcomas-quantified-by-mri
#20
Mikael Skorpil, Henric Rydén, Johan Wejde, Elisabet Lidbrink, Otte Brosjö, Johan Berglund
BACKGROUND: Myxoid liposarcomas are highly radiosensitive. Consequently radiotherapy is often used pre-operatively to reduce tumor volume and lessen the post-operative deficit. In soft-tissue sarcomas therapy response is mainly evaluated using magnetic resonance imaging (MRI) and the fundamental criterion for a positive response is decreased tumor size. In myxoid liposarcomas an increased fat content is also known to occur as a response to radiotherapy. OBJECTIVE: To highlight the difficulties of MRI for therapy response evaluation in irradiated myxoid liposarcomas, by using MRI Dixon techniques enabling objective quantification of proton density fat fraction (%) and the number of double bonds (ndb; unsaturation degree) of fatty acids...
November 2017: Magnetic Resonance Imaging
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