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MR elastography

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
I G Murphy, M J Graves, S Reid, A J Patterson, I Patterson, A N Priest, D 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
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
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
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
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
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
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
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
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
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
Nimantha M W de Alwis, Quentin M Anstee, Christopher P Day
Patients with nonalcoholic fatty liver disease (NAFLD) are asymptomatic and present with either unexplained abnormal liver blood tests or a bright liver on ultrasonography. Some patients will have normal liver blood tests raising the issue of whether patients with risk factors for NAFLD (diabetes and/or metabolic syndrome [MS]) should be screened for its presence with biomarkers, such as the fatty liver index (FLI). The diagnosis of NAFLD requires the exclusion of other causes of chronic liver disease and steatosis, especially heavy alcohol consumption and viral hepatitis particularly HCV genotype 3...
2016: Digestive Diseases
Ryan W Stidham, Peter Dr Higgins
Crohn's disease (CD) activity assessments are dominated by inflammatory changes without discrete measurement of the coexisting fibrotic contribution to total bowel damage. Intestinal fibrosis impacts the development of severe structural complications and the overall natural history of CD. Measuring intestinal fibrosis is challenging and existing methods of disease assessment are unable to reliably distinguish fibrosis from inflammation. Both the immediate clinical need to measure fibrosis for therapeutic decision-making and the near-future need for tools to assess pipeline anti-fibrotic medications highlight the demand for biomarkers of fibrosis in CD...
August 2016: United European Gastroenterology Journal
Michael L Wells, Michael R Moynagh, Rickey E Carter, Robert A Childs, Cameron E Leitch, Joel G Fletcher, Benjamin M Yeh, Sudhakar K Venkatesh
PURPOSE: To compare MR hepatic fractional extracellular space (fECS) to liver stiffness (LS) with magnetic resonance elastography (MRE) for evaluation of liver fibrosis. METHODS AND MATERIALS: 71 consecutive patients with suspected chronic liver disease underwent standard liver MRI with MR elastography and additional delayed Gd-DTPA-enhanced sequences at 5 and 10 min in order to calculate hepatic fECS (%) and LS (kilopascals, kPa). Two radiologists blinded to clinical history examined MR images and calculated fECS and LS in identical locations for every patient...
August 10, 2016: Abdominal Radiology
Yogesh K Mariappan, Bogdan Dzyubak, Kevin J Glaser, Sudhakar K Venkatesh, Claude B Sirlin, Jonathan Hooker, Kiaran P McGee, Richard L Ehman
Purpose To (a) evaluate modified spin-echo (SE) magnetic resonance (MR) elastographic sequences for acquiring MR images with improved signal-to-noise ratio (SNR) in patients in whom the standard gradient-echo (GRE) MR elastographic sequence yields low hepatic signal intensity and (b) compare the stiffness values obtained with these sequences with those obtained with the conventional GRE sequence. Materials and Methods This HIPAA-compliant retrospective study was approved by the institutional review board; the requirement to obtain informed consent was waived...
August 10, 2016: Radiology
Dong Ho Lee, Jeong Min Lee, Nam-Joon Yi, Kwang-Woong Lee, Kyung-Suk Suh, Jeong-Hoon Lee, Kyung Bun Lee, Joon Koo Han
PURPOSE: To evaluate prognostic value of hepatic stiffness (HS) measurement using MR elastography (MRE) in patients with hepatocellular carcinoma (HCC) treated by hepatic resection (HR). METHODS: We enrolled 144 patients with Barcelona Clinic Liver Cancer stage A HCCs initially treated by HR who underwent preoperative liver MRE between January 2010 and June 2013. HS values were measured using MRE. Receiver operating characteristics (ROC) and multivariate logistic regression analyses were used to determine significant predictive factors for posthepatecomy liver failure (PHLF)...
July 25, 2016: European Radiology
Nicolò Pipitone
PURPOSE OF REVIEW: This review aims at covering the role of muscle MRI in supporting the diagnosis of myositis, in aiding to differentiate it from other muscle disorders, and in monitoring myositis patients over time by assessing response to treatment and by discriminating between muscle inflammation and chronic damage. RECENT FINDINGS: MRI can assist in 'pattern recognition' of muscle involvement across numerous myopathies, including myositis. Novel applications of magnetic resonance such as cardiac MRI, MR elastography and blood oxigenation level-dependent magnetic resonance can shed light on different aspects of myositis and usefully complement conventional MRI in assessing patients with myositis...
November 2016: Current Opinion in Rheumatology
C Lemaitre, S Dominique, E Billoud, M Eliezer, H Montialoux, M Quillard, G Riachi, E Koning, H Morisse-Pradier, G Savoye, C Savoye-Collet, O Goria
Background. Cystic fibrosis-associated liver disease (CFLD) is a major cause of death. The objective of our retrospective study was to describe the relevance of magnetic resonance imaging (MRI) and liver stiffness measurement (LSM) for CFLD evaluation. Methods. All cystic fibrosis adult patients evaluated by MRI and LSM were included. MR signs of portal hypertension (PHT), dysmorphia, or cholangitis were collected and LSM expressed in kPa and Metavir. Results. Of 25 patients, 52% had abnormal MRI. Median LSM was 5...
2016: Canadian Respiratory Journal: Journal of the Canadian Thoracic Society
Mike Bradley
The aim of this study was to evaluate whether compression elastography has a useful role in the planning of percutaneous ultrasound-guided biopsies of soft tissue tumours. Consecutive patients were evaluated in the sarcoma clinic after their initial imaging work-up, involving ultrasound and MR. The multi-disciplinary team decided when percutaneous biopsy for histology was required, and this was performed in the multi-disciplinary clinic using ultrasound guidance. An experienced sarcoma radiologist performed the ultrasound with compression elastography in all cases...
November 2015: Ultrasound: Journal of the British Medical Ultrasound Society
Deirdre M McGrath, Nishant Ravikumar, Leandro Beltrachini, Iain D Wilkinson, Alejandro F Frangi, Zeike A Taylor
PURPOSE: MR elastography (MRE) of the brain is being explored as a biomarker of neurodegenerative disease such as dementia. However, MRE measures for healthy brain have varied widely. Differing wave delivery methodologies may have influenced this, hence finite element-based simulations were performed to explore this possibility. METHODS: The natural frequencies of a series of cranial models were calculated, and MRE-associated vibration was simulated for different wave delivery methods at varying frequency, using simple isotropic viscoelastic material models for the brain...
July 15, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
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