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Water fat imaging

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https://www.readbyqxmd.com/read/28238449/the-feasibility-of-semi-automatically-generated-red-bone-marrow-segmentations-based-on-mr-only-for-patients-with-gynecologic-cancer
#1
Anna Andreychenko, Petra S Kroon, Matteo Maspero, Ina Jürgenliemk-Schulz, Astrid A C De Leeuw, Marnix G E H Lam, Jan J W Lagendijk, Cornelis A T van den Berg
PURPOSE: For patients with cervical cancer the delivery of chemotherapy with radiotherapy improves survival compared with radiotherapy alone. However, high rates of acute hematologic toxicity occur when combining both therapies due to the damage of the red bone marrow (RBM). This study aimed to reduce the radiation damage to the RBM. A tool has been developed for semi-automatic delineation of the red bone marrow based on MR-only. This delineation can be included into the treatment planning process to reduce the volume of RBM irradiated in patients receiving pelvic radiation therapy...
February 23, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/28236649/spectral-characterization-of-tissues-in-high-spectral-and-spatial-resolution-mr-images-implications-for-a-classification-based-synthetic-ct-algorithm
#2
Abbie M Wood, Steven M Shea, Milica Medved, Gregory S Karczmar, Murat Surucu, Sebastien Gros, William Small, John Roeske
PURPOSE: To characterize spectral parameters of tissues with high spectral and spatial resolution magnetic resonance images to be used as a foundation for a classification-based synthetic CT algorithm. METHODS: A phantom was constructed consisting of a section of fresh beef leg with bone embedded in a 1% agarose gel. The high spectral and spatial (HiSS) resolution MR imaging sequence used had 1.0mm in-plane resolution and 11.1Hz spectral resolution. This sequence was used to image the phantom and one patient...
February 25, 2017: Medical Physics
https://www.readbyqxmd.com/read/28225576/3d-multiecho-dixon-for-the-evaluation-of-hepatic-iron-and-fat-in-a-clinical-setting
#3
Benjamin Henninger, Heinz Zoller, Stephan Kannengiesser, Xiaodong Zhong, Werner Jaschke, Christian Kremser
PURPOSE: To prospectively evaluate a new 3D-multiecho-Dixon (3D-ME-Dixon) sequence for the quantification of hepatic iron and fat in a clinical setting. MATERIALS AND METHODS: In all, 120 patients underwent 1.5T magnetic resonance imaging of the liver between December 2013 and June 2015 including the following three sequences: 3D-ME-Dixon with inline calculation of R2* and proton-density fat-fraction (PDFF) maps, single-voxel-spectroscopy (SVS), 2D multigradient-echo sequence (2D-ME-GRE)...
February 22, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28216452/water-and-lipid-diffusion-mri-using-chemical-shift-displacement-based-separation-of-lipid-tissue-split
#4
Naoki Ohno, Hirohito Kan, Tosiaki Miyati, Toshitaka Aoki, Shota Ishida, Toshifumi Gabata
PURPOSE: To obtain water and lipid diffusion-weighted images (DWIs) simultaneously, we devised a novel method utilizing chemical shift displacement-based separation of lipid tissue (SPLIT) imaging. MATERIALS AND METHODS: Single-shot diffusion echo-planar imaging without fat suppression was used and the imaging parameters were optimized to separate water and lipid DWIs by chemical shift displacement of the lipid signals along the phase-encoding direction. Using the optimized conditions, transverse DWIs at the maximum diameter of the right calf were scanned with multiple b-values in five healthy subjects...
February 16, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28190853/high-snr-acquisitions-improve-the-repeatability-of-liver-fat-quantification-using-confounder-corrected-chemical-shift-encoded-mr-imaging
#5
Utaroh Motosugi, Diego Hernando, Curtis Wiens, Peter Bannas, Scott B Reeder
PURPOSE: To determine whether high signal-to-noise ratio (SNR) acquisitions improve the repeatability of liver proton density fat fraction (PDFF) measurements using confounder-corrected chemical shift-encoded magnetic resonance (MR) imaging (CSE-MRI). MATERIALS AND METHODS: Eleven fat-water phantoms were scanned with 8 different protocols with varying SNR. After repositioning the phantoms, the same scans were repeated to evaluate the test-retest repeatability. Next, an in vivo study was performed with 20 volunteers and 28 patients scheduled for liver magnetic resonance imaging (MRI)...
February 13, 2017: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/28190639/characterizing-white-matter-changes-in-chronic-schizophrenia-a-free-water-imaging-multi-site-study
#6
Lena K L Oestreich, Amanda E Lyall, Ofer Pasternak, Zora Kikinis, Dominick T Newell, Peter Savadjiev, Sylvain Bouix, Martha E Shenton, Marek Kubicki, Thomas J Whitford, Simon McCarthy-Jones
Diffusion tensor imaging (DTI) studies in chronic schizophrenia have found widespread but often inconsistent patterns of white matter abnormalities. These studies have typically used the conventional measure of fractional anisotropy, which can be contaminated by extracellular free-water. A recent free-water imaging study reported reduced free-water corrected fractional anisotropy (FAT) in chronic schizophrenia across several brain regions, but limited changes in the extracellular volume. The present study set out to validate these findings in a substantially larger sample...
February 10, 2017: Schizophrenia Research
https://www.readbyqxmd.com/read/28168529/imaging-properties-of-3d-printed-materials-multi-energy-ct-of-filament-polymers
#7
James Shin, Ranjit S Sandhu, George Shih
Clinical applications of 3D printing are increasingly commonplace, likewise the frequency of inclusion of 3D printed objects on imaging studies. Although there is a general familiarity with the imaging appearance of traditional materials comprising common surgical hardware and medical devices, comparatively less is known regarding the appearance of available 3D printing materials in the consumer market. This work detailing the CT appearance of a selected number of common filament polymer classes is an initial effort to catalog these data, to provide for accurate interpretation of imaging studies incidentally or intentionally including fabricated objects...
February 6, 2017: Journal of Digital Imaging: the Official Journal of the Society for Computer Applications in Radiology
https://www.readbyqxmd.com/read/28150873/dual-echo-dixon-imaging-with-a-constrained-phase-signal-model-and-graph-cuts-reconstruction
#8
Eric G Stinson, Joshua D Trzasko, Joel G Fletcher, Stephen J Riederer
PURPOSE: The purpose of this work is to derive and demonstrate constrained-phase dual-echo Dixon imaging within a maximum likelihood framework solved with a regularized graph-cuts-guided optimization. THEORY AND METHODS: Dual-echo Dixon reconstruction is fundamentally underdetermined; however, adopting a constrained-phase signal model reduces the number of unknowns and the nonlinear problem can be solved under a maximum likelihood framework. Period shifts in the field map (manifesting as fat/water signal swaps) must also be corrected...
February 2, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28130811/relation-between-brown-adipose-tissue-and-measures-of-obesity-and-metabolic-dysfunction-in-patients-with-cardiovascular-disease
#9
Bas T Franssens, Hans Hoogduin, Tim Leiner, Yolanda van der Graaf, Frank L J Visseren
PURPOSE: To evaluate whether brown adipose tissue (BAT) is present in middle-aged patients with cardiovascular comorbidities and to quantify how BAT presence associates with obesity and metabolic dysfunction. MATERIALS AND METHODS: Supraclavicular and subcutaneous adipose tissue fat-signal-fraction (FF) was determined with 1.5T water-fat magnetic resonance imaging (MRI) in 50 patients with coronary artery disease, cerebrovascular disease, or peripheral artery disease...
January 27, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28117559/anatomic-study-of-renal-arterial-vasculature-and-its-potential-implication-on-partial-nephrectomy
#10
Veronica Macchi, Alessandro Crestani, Andrea Porzionato, Maria Martina Sfriso, Aldo Morra, Marta Rossanese, Giacomo Novara, Raffaele De Caro, Vincenzo Ficarra
BACKGROUND AND OBJECTIVES: A detailed understanding of surgical anatomy is an essential requisite to maximize perioperative and functional outcomes of partial nephrectomy. The objectives of this study were 1) to validate the Graves classification and 2) to verify the real absence of collateral arterial blood-supply between different renal segments. MATERIAL AND METHODS: The study was performed on 15 normal kidneys sampled from 8 un-embalmed cadavers. Kidneys with the surrounding perirenal fat tissue were removed en bloc with the abdominal segment of the aorta...
January 24, 2017: BJU International
https://www.readbyqxmd.com/read/28112410/hybrid-zte-dixon-mr-based-attenuation-correction-for-quantitative-uptake-estimation-of-pelvic-lesions-in-pet-mri
#11
Andrew P Leynes, Jaewon Yang, Dattesh D Shanbhag, Sandeep S Kaushik, Youngho Seo, Thomas A Hope, Florian Wiesinger, Peder E Z Larson
PURPOSE: This study introduces a new hybrid ZTE/Dixon MR-based attenuation correction (MRAC) method including bone density estimation for PET/MRI and quantifies the effects of bone attenuation on metastatic lesions uptake in the pelvis. METHODS: Six patients with pelvic lesions were scanned using fluorodeoxyglucose (18F-FDG) in an integrated time-of-flight (TOF) PET/MRI system. For PET attenuation correction, MR imaging consisted of two-point Dixon and zero echo-time (ZTE) pulse sequences...
January 23, 2017: Medical Physics
https://www.readbyqxmd.com/read/28110367/accurate-simultaneous-quantification-of-liver-steatosis-and-iron-overload-in-diffuse-liver-diseases-with-mri
#12
Manuela França, Ángel Alberich-Bayarri, Luis Martí-Bonmatí, Pedro Oliveira, Francisca Emanuel Costa, Graça Porto, José Ramón Vizcaíno, Javier Sanchez Gonzalez, Eduardo Ribeiro, João Oliveira, Helena Pessegueiro Miranda
PURPOSE: To evaluate the diagnostic performances of 3 Tesla multi-echo chemical shift-encoded gradient echo magnetic resonance (MECSE-MR) imaging to simultaneously quantify liver steatosis and iron overload in a wide spectrum of diffuse liver diseases having biopsy as reference standard. METHODS: MECSE-MR-acquired images were used to calculate fat fraction and iron content in a single breath-hold in 109 adult patients. Proton density fat fraction (PDFF) was prospectively estimated using complex-based data reconstruction with multipeak fat modeling...
January 21, 2017: Abdominal Radiology
https://www.readbyqxmd.com/read/28104990/sitagliptin-in-patients-with-non-alcoholic-steatohepatitis-a-randomized-placebo-controlled-trial
#13
Tisha R Joy, Charles A McKenzie, Rommel G Tirona, Kelly Summers, Shannon Seney, Subrata Chakrabarti, Neel Malhotra, Melanie D Beaton
AIM: To evaluate the effect of sitagliptin vs placebo on histologic and non-histologic parameters of non-alcoholic steatohepatitis (NASH). METHODS: Twelve patients with biopsy-proven NASH were randomized to sitagliptin (100 mg daily) (n = 6) or placebo (n = 6) for 24 wk. The primary outcome was improvement in liver fibrosis after 24 wk. Secondary outcomes included evaluation of changes in NAFLD activity score (NAS), individual components of NAS (hepatocyte ballooning, lobular inflammation, and steatosis), glycemic control and insulin resistance [including measurements of glycated hemoglobin (HbA1C) and adipocytokines], lipid profile including free fatty acids, adipose distribution measured using magnetic resonance imaging (MRI), and thrombosis markers (platelet aggregation and plasminogen activator inhibitor 1 levels)...
January 7, 2017: World Journal of Gastroenterology: WJG
https://www.readbyqxmd.com/read/28103921/manually-defining-regions-of-interest-when-quantifying-paravertebral-muscles-fatty-infiltration-from-axial-magnetic-resonance-imaging-a-proposed-method-for-the-lumbar-spine-with-anatomical-cross-reference
#14
Rebecca J Crawford, Jon Cornwall, Rebecca Abbott, James M Elliott
BACKGROUND: There is increasing interest in paravertebral muscle composition as a potential prognostic and diagnostic element in lumbar spine health. As a consequence, it is becoming popular to use magnetic resonance imaging (MRI) to examine muscle volume and fatty infiltration in lumbar paravertebral muscles to assess both age-related change and their clinical relevance in low back pain (LBP). A variety of imaging methods exist for both measuring key variables (fat, muscle) and for defining regions of interest, making pooled comparisons between studies difficult and rendering post-production analysis of MRIs confusing...
January 19, 2017: BMC Musculoskeletal Disorders
https://www.readbyqxmd.com/read/28092409/quantification-of-brown-and-white-adipose-tissue-based-on-gaussian-mixture-model-using-water-fat-and-t2-mri-in-adolescents
#15
Steve C N Hui, Jacky K L Ko, Teng Zhang, Lin Shi, David K W Yeung, Defeng Wang, Queenie Chan, Winnie C W Chu
PURPOSE: To develop a technique for the separation and quantification of brown adipose tissue (BAT) and white adipose tissue (WAT) using fat fraction and T2* intensity based on the Gaussian mixture model (GMM). MATERIALS AND METHODS: Chemical-shift water-fat and T2* images were acquired at the neck, supraclavicular, interscapular, and paravertebral regions in 24 volunteers (Obese: n = 12, female/male = 6/6, body mass index [BMI] = 31.3 ± 2.3 kg/m(2) , age = 16...
January 16, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28074609/rapid-chemical-shift-encoding-with-single-acquisition-single-slab-3d-grase
#16
Hahnsung Kim, Dong-Hyun Kim, Chul-Ho Sohn, Jaeseok Park
PURPOSE: To investigate the feasibility of chemical shift encoded, single-slab 3D GRASE for rapid fat-water separation within a single acquisition. METHODS: The proposed method incorporates signal-to-noise-ratio-optimal chemical shift encoding into single-slab 3D GRASE with variable flip angles. Chemical shift induced phase information was encoded in succession to different positions in k-space by inserting phase encoding blips between adjacent lobes of the oscillating readout gradients...
January 11, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28074498/imaging-and-t2-relaxometry-of-short-t2-connective-tissues-in-the-knee-using-ultrashort-echo-time-double-echo-steady-state-utedess
#17
Akshay S Chaudhari, Bragi Sveinsson, Catherine J Moran, Emily J McWalter, Ethan M Johnson, Tao Zhang, Garry E Gold, Brian A Hargreaves
PURPOSE: To develop a radial, double-echo steady-state (DESS) sequence with ultra-short echo-time (UTE) capabilities for T2 measurement of short-T2 tissues along with simultaneous rapid, signal-to-noise ratio (SNR)-efficient, and high-isotropic-resolution morphological knee imaging. METHODS: THe 3D radial UTE readouts were incorporated into DESS, termed UTEDESS. Multiple-echo-time UTEDESS was used for performing T2 relaxometry for short-T2 tendons, ligaments, and menisci; and for Dixon water-fat imaging...
January 11, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28064372/effects-of-bariatric-surgery-on-non-alcoholic-fatty-liver-disease-magnetic-resonance-imaging-is-an-effective-non-invasive-method-to-evaluate-changes-in-the-liver-fat-fraction
#18
Dennis M Hedderich, Till Hasenberg, Stefan Haneder, Stefan O Schoenberg, Özlem Kücükoglu, Ali Canbay, Mirko Otto
INTRODUCTION: Non-alcoholic fatty liver disease (NAFLD) is considered the most common liver disease worldwide and is highly associated with obesity. The prevalences of both conditions have markedly increased in the Western civilization. Bariatric surgery is the most effective treatment for morbid obesity and its comorbidities such as NAFLD. OBJECTIVES: Measure postoperative liver fat fraction (LFF) in bariatric patients by using in-opposed-phase MRI, a widely available clinical tool validated for the quantification of liver fat METHODS: Retrospective analyses of participants, who underwent laparoscopic Roux-Y-gastric-bypass (17) or laparoscopic sleeve gastrectomy (2) were performed using magnetic resonance imaging (MRI), bioelectrical impedance analysis (BIA), and anthropometric measurements 1 day before surgery, as well as 6, 12, and 24 weeks after surgery, LFF was calculated from fat-only and water-only MR images...
January 7, 2017: Obesity Surgery
https://www.readbyqxmd.com/read/28060254/quantitative-magnetic-resonance-imaging-of-skeletal-muscle-disease
#19
Bruce M Damon, Ke Li, Richard D Dortch, E Brian Welch, Jane H Park, Amanda K W Buck, Theodore F Towse, Mark D Does, Daniel F Gochberg, Nathan D Bryant
Quantitative magnetic resonance imaging (qMRI) describes the development and use of MRI to quantify physical, chemical, and/or biological properties of living systems. Neuromuscular diseases often exhibit a temporally varying, spatially heterogeneous, and multi-faceted pathology. The goal of this protocol is to characterize this pathology using qMRI methods. The MRI acquisition protocol begins with localizer images (used to locate the position of the body and tissue of interest within the MRI system), quality control measurements of relevant magnetic field distributions, and structural imaging for general anatomical characterization...
December 18, 2016: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28048911/su-g-iep1-06-estimating-relative-tissue-density-from-quantitative-mr-images-a-novel-perspective-for-mri-only-heterogeneity-corrected-dose-calculation
#20
A Soliman, M Hashemi, H Safigholi, E Tchistiakova, W Song
PURPOSE: To explore the feasibility of extracting the relative density from quantitative MRI measurements as well as estimate a correlation between the extracted measures and CT Hounsfield units. METHODS: MRI has the ability to separate water and fat signals, producing two separate images for each component. By performing appropriate corrections on the separated images, quantitative measurement of water and fat mass density can be estimated. This work aims to test this hypothesis on 1...
June 2016: Medical Physics
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