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MR elastography

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https://www.readbyqxmd.com/read/27873040/can-mri-predict-meningioma-consistency-a-correlation-with-tumor-pathology-and-systematic-review
#1
REVIEW
Amy Yao, Margaret Pain, Priti Balchandani, Raj K Shrivastava
Tumor consistency is a critical factor that influences operative strategy and patient counseling. Magnetic resonance imaging (MRI) describes the concentration of water within living tissues and as such, is hypothesized to predict aspects of their biomechanical behavior. In meningiomas, MRI signal intensity has been used to predict the consistency of the tumor and its histopathological subtype, though its predictive capacity is debated in the literature. We performed a systematic review of the PubMed database since 1990 concerning MRI appearance and tumor consistency to assess whether or not MRI can be used reliably to predict tumor firmness...
November 21, 2016: Neurosurgical Review
https://www.readbyqxmd.com/read/27861111/diagnostic-performance-of-mr-elastography-and-vibration-controlled-transient-elastography-in-the-detection-of-hepatic-fibrosis-in-patients-with-severe-to-morbid-obesity
#2
Jun Chen, Meng Yin, Jayant A Talwalkar, Jennifer Oudry, Kevin J Glaser, Thomas C Smyrk, Véronique Miette, Laurent Sandrin, Richard L Ehman
Purpose To evaluate the diagnostic performance and examination success rate of magnetic resonance (MR) elastography and vibration-controlled transient elastography (VCTE) in the detection of hepatic fibrosis in patients with severe to morbid obesity. Materials and Methods This prospective and HIPAA-compliant study was approved by the institutional review board. A total of 111 patients (71 women, 40 men) participated. Written informed consent was obtained from all patients. Patients underwent MR elastography with two readers and VCTE with three observers to acquire liver stiffness measurements for liver fibrosis assessment...
November 18, 2016: Radiology
https://www.readbyqxmd.com/read/27859956/noninvasive-hepatic-fibrosis-staging-using-mr-elastography-the-usefulness-of-the-bayesian-prediction-method
#3
Shintaro Ichikawa, Utaroh Motosugi, Nobuyuki Enomoto, Masanori Matsuda, Hiroshi Onishi
PURPOSE: To evaluate the usefulness of the Bayesian method for hepatic fibrosis staging with magnetic resonance elastography (MRE). MATERIALS AND METHODS: The sample of this retrospective study comprised patients with chronic liver disease (n = 309), in whom histopathological fibrosis staging and MRE using either a 1.5T (n = 214) or a 3T magnetic resonance imaging (MRI) system (n = 95) had been performed. The optimal cutoff stiffness value was determined and used to calculate the discrimination ability of fibrosis staging by the cutoff method...
November 9, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27859840/value-of-mr-elastography-for-the-preoperative-estimation-of-liver-regeneration-capacity-in-patients-with-hepatocellular-carcinoma
#4
Siwon Jang, Jeong Min Lee, Dong Ho Lee, Ijin Joo, Jeong Hee Yoon, Won Chang, Joon Koo Han
PURPOSE: To demonstrate the negative relationship between liver stiffness (LS) values measured at preoperative magnetic resonance elastography (MRE) and the regeneration capacity of the remnant liver after major hepatectomy, in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Thirty-eight patients with HCC (mean age, 57.1) who had undergone liver computed tomography (CT) and 1.5T MRE prior to right hepatectomy were included in this retrospective study...
November 16, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27845245/mr-elastography-of-hepatocellular-carcinoma-correlation-of-tumor-stiffness-with-histopathology-features-preliminary-findings
#5
Scott M Thompson, Jin Wang, Vishal S Chandan, Kevin J Glaser, Lewis R Roberts, Richard L Ehman, Sudhakar K Venkatesh
PURPOSE: To determine if tumor stiffness by MR Elastography (MRE) is associated with hepatocellular carcinoma (HCC) pathologic features. MATERIAL AND METHODS: A retrospective review was undertaken of all patients with pathologically confirmed HCC who underwent MRE prior to loco-regional therapy, surgical resection or transplant between 1/1/2007 to 12/31/2015. An independent observer measured tumor stiffness (kilopascals, kPa) by drawing regions of interest (ROI) covering the HCC and in the case of HCCs with non-enhancing/necrotic components, only the solid portion was included in the ROI...
November 11, 2016: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/27822656/k-space-data-processing-for-magnetic-resonance-elastography-mre
#6
Nadège Corbin, Elodie Breton, Michel de Mathelin, Jonathan Vappou
OBJECTIVE: Magnetic resonance elastography (MRE) requires substantial data processing based on phase image reconstruction, wave enhancement, and inverse problem solving. The objective of this study is to propose a new, fast MRE method based on MR raw data processing, particularly adapted to applications requiring fast MRE measurement or high elastogram update rate. MATERIALS AND METHODS: The proposed method allows measuring tissue elasticity directly from raw data without prior phase image reconstruction and without phase unwrapping...
November 7, 2016: Magma
https://www.readbyqxmd.com/read/27788034/hepatic-fibrosis-inflammation-and-steatosis-influence-on-the-mr-viscoelastic-and-diffusion-parameters-in-patients-with-chronic-liver-disease
#7
Helena S Leitão, Sabrina Doblas, Philippe Garteiser, Gaspard d'Assignies, Valérie Paradis, Feryel Mouri, Carlos F G C Geraldes, Maxime Ronot, Bernard E Van Beers
Purpose To determine the relationship of liver fibrosis, inflammation, and steatosis with the magnetic resonance (MR) viscoelastic and diffusion parameters in patients with chronic liver disease and to compare the diagnostic accuracy of the imaging parameters in staging liver fibrosis. Materials and Methods Consecutive patients with chronic liver disease scheduled for liver biopsy were prospectively recruited from November 2010 to October 2012 for this institutional review board-approved study after they provided written informed consent...
October 27, 2016: Radiology
https://www.readbyqxmd.com/read/27779802/quantification-of-breast-stiffness-using-mr-elastography-at-3-tesla-with-a-soft-sternal-driver-a-reproducibility-study
#8
Jeffrey R Hawley, Prateek Kalra, Xiaokui Mo, Brian Raterman, Lisa D Yee, Arunark Kolipaka
PURPOSE: Previous studies of breast MR elastography (MRE) evaluated the technique at magnetic field strengths of 1.5 Tesla (T) with the breast in contact with the driver. The aim of this study is to evaluate breast stiffness measurements and their reproducibility using a soft sternal driver at 3T and compare the results with qualitative measures of breast density. MATERIALS AND METHODS: Twenty-two healthy volunteers each underwent two separate breast MRE scans in a 3T MRI...
October 25, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27778429/multi-parametric-magnetic-resonance-imaging-for-the-assessment-of-non-alcoholic-fatty-liver-disease-severity
#9
Michael Pavlides, Rajarshi Banerjee, Elizabeth M Tunnicliffe, Catherine Kelly, Jane Collier, Lai Mun Wang, Kenneth A Fleming, Jeremy F Cobbold, Matthew D Robson, Stefan Neubauer, Eleanor Barnes
BACKGROUND AND AIMS: The diagnosis of non-alcoholic steatohepatitis (NASH) and fibrosis staging are central to non-alcoholic fatty liver disease (NAFLD) assessment. We evaluated multi-parametric magnetic resonance (MR) in the assessment of NASH and fibrosis using histology as standard in NAFLD. METHODS: Seventy one patients with suspected NAFLD were recruited within one month of liver biopsy. MR data were used to define the liver inflammation and fibrosis score (LIF 0-4)...
October 25, 2016: Liver International: Official Journal of the International Association for the Study of the Liver
https://www.readbyqxmd.com/read/27755913/liver-stiffness-values-are-lower-in-pediatric-subjects-than-in-adults-and-increase-with-age-a-multifrequency-mr-elastography-study
#10
Emily Etchell, Lauriane Jugé, Alice Hatt, Ralph Sinkus, Lynne E Bilston
Purpose To determine if healthy hepatic mechanical properties differ between pediatric and adult subjects at magnetic resonance (MR) elastography. Materials and Methods Liver shear moduli in 24 healthy pediatric participants (13 children aged 5-14 years [seven boys, six girls] and 11 adolescents aged 15-18 years [six boys, five girls]) and 10 healthy adults (aged 22-36 years [five men, five women]) were obtained with 3-T MR elastography at 28, 56, and 84 Hz. Relationships between shear moduli and age were assessed with Spearman correlations...
October 17, 2016: Radiology
https://www.readbyqxmd.com/read/27746391/comparison-of-breath-hold-respiratory-navigated-and-free-breathing-mr-elastography-of-the-liver
#11
Ian Gavin Murphy, Martin J Graves, Scott Reid, Andrew J Patterson, Ilse Patterson, Andrew N Priest, David J Lomas
PURPOSE: Hepatic magnetic resonance elastography (MRE) is currently a breath-hold imaging technique. Patients with chronic liver disease can have comorbidities that limit their ability to breath-hold (BH) for the required acquisition time. Our aim was to evaluate whether stiffness measurements obtained from a navigator-triggered MRE acquisition are comparable to standard expiratory breath-hold, inspiratory breath-hold or free-breathing in healthy participants. MATERIALS AND METHODS: Twelve healthy participants were imaged using the four methods on a clinical 1...
October 13, 2016: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/27726414/accuracy-of-liver-fat-quantification-with-advanced-ct-mri-and-ultrasound-techniques-prospective-comparison-with-mr-spectroscopy
#12
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/27725575/preliminary-comparison-of-multi-scale-and-multi-model-direct-inversion-algorithms-for-3t-mr-elastography
#13
Kengo Yoshimitsu, Yoshinobu Shinagawa, Toshimichi Mitsufuji, Emi Mutoh, Hiroshi Urakawa, Keiko Sakamoto, Ritsuko Fujimitsu, Koichi Takano
PURPOSE: To elucidate whether any differences are present in the stiffness map obtained with a multiscale direct inversion algorithm (MSDI) vs that with a multimodel direct inversion algorithm (MMDI), both qualitatively and quantitatively. MATERIALS AND METHODS: The MR elastography (MRE) data of 37 consecutive patients who underwent liver MR elastography between September and October 2014 were retrospectively analyzed by using both MSDI and MMDI. Two radiologists qualitatively assessed the stiffness maps for the image quality in consensus, and the measured liver stiffness and measurable areas were quantitatively compared between MSDI and MMDI...
October 11, 2016: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/27715486/spin-echo-echo-planar-imaging-mr-elastography-versus-gradient-echo-mr-elastography-for-assessment-of-liver-stiffness-in-children-and-young-adults-suspected-of-having-liver-disease
#14
Suraj D Serai, Jonathan R Dillman, Andrew T Trout
Purpose To compare two-dimensional (2D) gradient-recalled echo (GRE) and 2D spin-echo (SE) echo-planar imaging (EPI) magnetic resonance (MR) elastography for measurement of hepatic stiffness in pediatric and young adult patients suspected of having liver disease. Materials and Methods In this institutional review board-approved, HIPAA-compliant study, 58 patients underwent both 2D GRE and 2D SE-EPI MR elastography at 1.5 T during separate breath holds. Liver stiffness (mean of means; in kilopascals) was measured by five blinded reviewers...
October 10, 2016: Radiology
https://www.readbyqxmd.com/read/27699875/tomoelastography-of-the-abdomen-tissue-mechanical-properties-of-the-liver-spleen-kidney-and-pancreas-from-single-mr-elastography-scans-at-different-hydration-states
#15
Florian Dittmann, Heiko Tzschätzsch, Sebastian Hirsch, Eric Barnhill, Jürgen Braun, Ingolf Sack, Jing Guo
PURPOSE: To develop a compact magnetic resonance elastography (MRE) protocol for abdomen and to investigate the effect of water uptake on tissue stiffness in the liver, spleen, kidney, and pancreas. METHODS: Nine asymptomatic volunteers were investigated by MRE before and after 1 liter water uptake. Shear-wave excitation at four frequencies was transferred to the abdomen from anterior and posterior directions using pressurized air drivers. Tomographic representations of shear-wave speed were produced by analysis of multifrequency wave numbers in axial and coronal images acquired within four breath-holds or under free breathing, respectively...
October 3, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/27689833/elastography-in-chronic-liver-disease-modalities-techniques-limitations-and-future-directions
#16
Aparna Srinivasa Babu, Michael L Wells, Oleg M Teytelboym, Justin E Mackey, Frank H Miller, Benjamin M Yeh, Richard L Ehman, Sudhakar K Venkatesh
Chronic liver disease has multiple causes, many of which are increasing in prevalence. The final common pathway of chronic liver disease is tissue destruction and attempted regeneration, a pathway that triggers fibrosis and eventual cirrhosis. Assessment of fibrosis is important not only for diagnosis but also for management, prognostic evaluation, and follow-up of patients with chronic liver disease. Although liver biopsy has traditionally been considered the reference standard for assessment of liver fibrosis, noninvasive techniques are the emerging focus in this field...
September 30, 2016: Radiographics: a Review Publication of the Radiological Society of North America, Inc
https://www.readbyqxmd.com/read/27662640/comparison-of-diagnostic-accuracies-of-two-and-three-dimensional-mr-elastography-of-the-liver
#17
Hiroyuki Morisaka, Utaroh Motosugi, Kevin J Glaser, Shintaro Ichikawa, Richard L Ehman, Katsuhiro Sano, Tomoaki Ichikawa, Hiroshi Onishi
PURPOSE: To evaluate the effect of imaging sequence (spin-echo echo-planar imaging [EPI] and gradient-echo [GRE]) and postprocessing method (two-dimensional [2D] and 3D inversion algorithms) on liver MR elastography (MRE) and to validate the diagnostic performance of EPI-MRE3D versus conventional GRE-MRE2D for liver fibrosis staging. MATERIALS AND METHODS: Three MRE methods (EPI-MRE3D , EPI-MRE2D , and GRE-MRE2D ) were performed on soft and mildly stiff phantoms and 58 patients with chronic liver disease using a 3 Tesla clinical MRI scanner, and stiffness values were compared among the three methods...
September 23, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27608454/gradient-based-optimization-for-poroelastic-and-viscoelastic-mr-elastography
#18
Likun Tan, Matthew McGarry, Elijah Van Houten, Ming Ji, Ligin Solamen, John Weaver, Keith Paulsen
We describe an efficient gradient computation for solving inverse problems arising in magnetic resonance elastography (MRE). The algorithm can be considered as a generalized 'adjoint method' based on a Lagrangian formulation. One requirement for the classic adjoint method is assurance of the self-adjoint property of the stiffness matrix in the elasticity problem. In this paper, we show this property is no longer a necessary condition in our algorithm, but the computational performance can be as efficient as the classic method, which involves only two forward solutions and is independent of the number of parameters to be estimated...
August 31, 2016: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/27579850/mechanical-analysis-of-an-axially-symmetric-cylindrical-phantom-with-a-spherical-heterogeneity-for-mr-elastography
#19
Benjamin L Schwartz, Ziying Yin, Richard L Magin
Cylindrical homogenous phantoms for magnetic resonance (MR) elastography in biomedical research provide one way to validate an imaging systems performance, but the simplified geometry and boundary conditions can cloak complexity arising at tissue interfaces. In an effort to develop a more realistic gel tissue phantom for MRE, we have constructed a heterogenous gel phantom (a sphere centrally embedded in a cylinder). The actuation comes from the phantom container, with the mechanical waves propagating toward the center, focusing the energy and thus allowing for the visualization of high-frequency waves that would otherwise be damped...
September 21, 2016: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/27564862/in-vivo-quantification-of-myocardial-stiffness-in-hypertensive-porcine-hearts-using-mr-elastography
#20
Ria Mazumder, Samuel Schroeder, Xiaokui Mo, Bradley D Clymer, Richard D White, Arunark Kolipaka
PURPOSE: To determine alteration in left ventricular (LV) myocardial stiffness (MS) with hypertension (HTN). Cardiac MR elastography (MRE) was used to estimate MS in HTN induced pigs and MRE-derived MS measurements were compared against LV pressure, thickness and circumferential strain. MATERIALS AND METHODS: Renal-wrapping surgery was performed to induce HTN in eight pigs. LV catheterization (to measure pressure) and cardiac MRI (1.5 Tesla; gradient echo-MRE and tagging) was performed pre-surgery at baseline (Bx), and post-surgery at month 1 (M1) and month 2 (M2)...
August 26, 2016: Journal of Magnetic Resonance Imaging: JMRI
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