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proton density MRI

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https://www.readbyqxmd.com/read/28076290/tailored-interactive-sequences-for-continuous-mr-image-guided-freehand-biopsies-of-different-organs-in-an-open-system-at-1-0-tesla-t-initial-experience
#1
Florian Streitparth, Christian Althoff, Martin Jonczyk, Felix Guettler, Martin Maurer, Hendrik Rathke, Keno Moritz Sponheuer, Bernd Hamm, Ulf K Teichgräber, Maximilian de Bucourt
OBJECTIVES: To assess the feasibility, image quality, and accuracy of freehand biopsies of liver, bone, muscle, vertebral disc, soft tissue, and other lesions using balanced steady-state free precession (SSFP, balanced fast field echo: bFFE), spoiled and nonspoiled gradient echo (FFE), and turbo spin echo (TSE) sequences for interactive continuous navigation in an open magnetic resonance imaging (MRI) system at 1.0 tesla (T). METHODS: Twenty-six MR-guided biopsies (five liver, five bone, four muscle, four vertebral disc, one lung, one kidney, one suprarenal gland, and five soft or other tissue) were performed in 23 patients in a 1...
January 11, 2017: Biomedizinische Technik. Biomedical Engineering
https://www.readbyqxmd.com/read/28063601/bone-marrow-fat-content-is-correlated-with-hepatic-fat-content-in-paediatric-non-alcoholic-fatty-liver-disease
#2
N Y Yu, T Wolfson, M S Middleton, G Hamilton, A Gamst, J E Angeles, J B Schwimmer, C B Sirlin
AIM: To investigate the relationship between bone marrow fat content and hepatic fat content in children with known or suspected non-alcoholic fatty liver disease (NAFLD). MATERIALS AND METHODS: This was an institutional review board-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant, cross-sectional, prospective analysis of data collected between October 2010 to March 2013 in 125 children with known or suspected NAFLD. Written informed consent was obtained for same-day research magnetic resonance imaging (MRI) of the lumbar spine, liver, and abdominal adiposity...
January 4, 2017: Clinical Radiology
https://www.readbyqxmd.com/read/28048262/su-g-iep1-07-inaccuracy-of-lesion-blood-flow-quantification-related-to-the-proton-density-reference-image-in-arterial-spin-labeling-mri-of-brain-tumors
#3
M Jen, J Johnson, P Hou, H Liu
PURPOSE: Cerebral blood flow quantification in arterial spin labeling (ASL) MRI requires an estimate of the equilibrium magnetization of blood, which is often obtained by a set of proton density (PD) reference image. Normally, a constant blood-brain partition coefficient is assumed across the brain. However, this assumption may not be valid for brain lesions. This study aimed to evaluate the impact of lesion-related PD variations on ASL quantification in patients with brain tumors. METHODS: MR images for posttreatment evaluation of 42 patients with brain tumors were retrospectively analyzed...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046967/su-g-iep1-09-mri-evaluation-of-a-direction-modulated-brachytherapy-dmbt-tandem-applicator-for-cervical-cancer-on-3t
#4
A Soliman, D Han, A Elzibak, H Safigholi, S Mashouf, A Owrangi, A Ravi, W Song
PURPOSE: To assess image quality and artifact extent of a novel direction modulated brachytherapy (DMBT) tandem applicator on a 3T MRI using various clinical imaging sequences. METHODS: The tandem applicator is composed of a tungsten alloy with 6 peripheral grooves covered with a PEEK tip. An MR-compatible phantom with similar dimensions to the female pelvis was manufactured. To visually assess the spatial shift of the applicator's tip, a mountable radial-fiducial with 4 plastic rods, each of 3mm diameter, was designed to tightly fit on the applicator...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046891/we-fg-206-12-enhanced-laws-textures-a-potential-mri-surrogate-marker-of-hepatic-fibrosis-in-a-murine-model
#5
B Li, H Yu, H Jara, J Soto, S Anderson
PURPOSE: To compare enhanced Laws texture derived from parametric proton density (PD) maps to other MRI-based surrogate markers (T2, PD, ADC) in assessing degrees of liver fibrosis in a murine model of hepatic fibrosis using 11.7T scanner. METHODS: This animal study was IACUC approved. Fourteen mice were divided into control (n=1) and experimental (n=13). The latter were fed a DDC-supplemented diet to induce hepatic fibrosis. Liver specimens were imaged using an 11...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28028556/effect-of-intravenous-gadoxetate-disodium-and-flip-angle-on-hepatic-proton-density-fat-fraction-estimation-with-six-echo-gradient-recalled-echo-magnitude-based-mr-imaging-at-3t
#6
Charlie C Park, Gavin Hamilton, Ajinkya Desai, Kevin A Zand, Tanya Wolfson, Jonathan C Hooker, Eduardo Costa, Elhamy Heba, Lisa Clark, Anthony Gamst, Rohit Loomba, Michael S Middleton, Claude B Sirlin
PURPOSE: The aim of the study was to determine in patients undergoing gadoxetate disodium (Gx)-enhanced MR exams whether proton density fat fraction (PDFF) estimation accuracy of magnitude-based multi-gradient-echo MRI (MRI-M) could be improved by using high flip angle (FA) on post-contrast images. MATERIALS AND METHODS: Thirty-one adults with known or suspected hepatic steatosis undergoing 3T clinical Gx-enhanced liver MRI were enrolled prospectively. MR spectroscopy (MRS), the reference standard, was performed before Gx to measure MRS-PDFF...
December 28, 2016: Abdominal Radiology
https://www.readbyqxmd.com/read/28018953/high-resolution-three-dimensional-quantitative-map-of-the-macromolecular-proton-fraction-distribution-in-the-normal-rat-brain
#7
Anna V Naumova, Andrey E Akulov, Marina Yu Khodanovich, Vasily L Yarnykh
The presented dataset provides a normative high-resolution three-dimensional (3D) macromolecular proton fraction (MPF) map of the healthy rat brain in vivo and source images used for its reconstruction. The images were acquired using the protocol described elsewhere (Naumova, et al. High-resolution three-dimensional macromolecular proton fraction mapping for quantitative neuroanatomical imaging of the rodent brain in ultra-high magnetic fields. Neuroimage (2016) doi: 10.1016/j.neuroimage.2016.09.036). The map was reconstructed from three source images with different contrast weightings (proton density, T1, and magnetization transfer) using the single-point algorithm with a synthetic reference image...
February 2017: Data in Brief
https://www.readbyqxmd.com/read/28005010/simultaneous-quantitative-imaging-of-electrical-properties-and-proton-density-from-b1-maps-using-mri
#8
Jiaen Liu, Pierre-Francois Van de Moortele, Xiaotong Zhang, Yicun Wang, Bin He
Electrical conductivity and permittivity of biological tissues are important diagnostic parameters and are useful for calculating subject-specific specific absorption rate distribution. On the other hand, water proton density also has clinical relevance for diagnosis purposes. These two kinds of tissue properties are inevitably associated in the technique of electrical properties tomography (EPT), which can be used to map in vivo electrical properties based on the measured B1 field distribution at Larmor frequency using magnetic resonance imaging (MRI)...
September 2016: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28002906/tears-of-popliteomeniscal-fascicles-diagnostic-and-clinical-implications-a-review-of-the-evidence
#9
R Papalia, R Simonetta, G Di Vico, G Torre, L Saccone, J Espregueira-Mendes, V Denaro
Postero-lateral corner of the knee is composed of several structures including the popliteo-meniscal fascicles (PMFs). These fibrous structures form a stable ligamentous complex around the popliteus tendon, which stabilize the lateral meniscus, increasing the strength of postero-lateral corner. Studies were retrieved through an electronic search of CINAHL, EMBASE, and Pub-Med, until May 2016. Studies in English, Italian, French, and Spanish were considered for inclusion. Randomized controlled trials, prospective and retrospective comparative studies, case series, and case reports were included...
October 2016: Journal of Biological Regulators and Homeostatic Agents
https://www.readbyqxmd.com/read/27999110/subclinical-disease-burden-as-assessed-by-whole-body-mri-in-subjects-with-prediabetes-subjects-with-diabetes-and-normal-control-subjects-from-the-general-population-the-kora-mri-study
#10
Fabian Bamberg, Holger Hetterich, Susanne Rospleszcz, Roberto Lorbeer, Sigrid D Auweter, Christopher L Schlett, Anina Schafnitzel, Christian Bayerl, Andreas Schindler, Tobias Saam, Katharina Müller-Peltzer, Wieland Sommer, Tanja Zitzelsberger, Jürgen Machann, Michael Ingrisch, Sonja Selder, Wolfgang Rathmann, Margit Heier, Birgit Linkohr, Christa Meisinger, Christian Weber, Birgit Ertl-Wagner, Steffen Massberg, Maximilian F Reiser, Annette Peters
Detailed pathophysiological manifestations of early disease in the context of prediabetes are poorly understood. This study aimed to evaluate the extent of early signs of metabolic and cardio-cerebrovascular complications affecting multiple organs in individuals with prediabetes. Subjects without a history of stroke, coronary artery disease, or peripheral artery disease were enrolled in a case-control study nested within the Cooperative Health Research in the Region of Augsburg (KORA) FF4 cohort and underwent comprehensive MRI assessment to characterize cerebral parameters (white matter lesions, microbleeds), cardiovascular parameters (carotid plaque, left ventricular function, and myocardial late gadolinium enhancement [LGE]), and metabolic parameters (hepatic proton-density fat fraction [PDFF] and subcutaneous and visceral abdominal fat)...
January 2017: Diabetes
https://www.readbyqxmd.com/read/27937040/multiparametric-or-practical-quantitative-liver-mri-towards-millisecond-fat-fraction-kilopascal-and-function-era
#11
Emre Unal, Ilkay Sedakat Idilman, Muşturay Karçaaltıncaba
New advances in liver magnetic resonance imaging (MRI) may enable diagnosis of unseen pathologies by conventional techniques. Normal T1 (550-620 ms for 1.5 T and 700-850 ms for 3 T), T2, T2* (>20 ms), T1rho (40-50 ms) mapping, proton density fat fraction (PDFF) (≤5%) and stiffness (2-3kPa) values can enable differentiation of a normal liver from chronic liver and diffuse diseases. Gd-EOB-DTPA can enable assessment of liver function by using postcontrast hepatobiliary phase or T1 reduction rate (normally above 60%)...
February 2017: Expert Review of Gastroenterology & Hepatology
https://www.readbyqxmd.com/read/27932506/synthetic-mri-in-the-detection-of-multiple-sclerosis-plaques
#12
A Hagiwara, M Hori, K Yokoyama, M Y Takemura, C Andica, T Tabata, K Kamagata, M Suzuki, K K Kumamaru, M Nakazawa, N Takano, H Kawasaki, N Hamasaki, A Kunimatsu, S Aoki
BACKGROUND AND PURPOSE: Synthetic MR imaging enables the creation of various contrast-weighted images including double inversion recovery and phase-sensitive inversion recovery from a single MR imaging quantification scan. Here, we assessed whether synthetic MR imaging is suitable for detecting MS plaques. MATERIALS AND METHODS: Quantitative and conventional MR imaging data on 12 patients with MS were retrospectively analyzed. Synthetic T2-weighted, FLAIR, double inversion recovery, and phase-sensitive inversion recovery images were produced after quantification of T1 and T2 values and proton density...
December 8, 2016: AJNR. American Journal of Neuroradiology
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
#13
Charlie C Park, Phirum Nguyen, Carolyn Hernandez, Ricki Bettencourt, Kimberly Ramirez, Lynda Fortney, Jonathan Hooker, Ethan Sy, Michael T Savides, 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 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/27889836/clinical-validation-of-synthetic-brain-mri-in-children-initial-experience
#14
Hollie West, James L Leach, Blaise V Jones, Marguerite Care, Rupa Radhakrishnan, Arnold C Merrow, Enrique Alvarado, Suraj D Serai
INTRODUCTION: The purpose of this study was to determine the diagnostic accuracy of synthetic MR sequences generated through post-acquisition processing of a single sequence measuring inherent R1, R2, and PD tissue properties compared with sequences acquired conventionally as part of a routine clinical pediatric brain MR exam. METHODS: Thirty-two patients underwent routine clinical brain MRI with conventional and synthetic sequences acquired (22 abnormal). Synthetic axial T1, T2, and T2 fluid attenuation inversion recovery or proton density-weighted sequences were made to match the comparable clinical sequences...
November 26, 2016: Neuroradiology
https://www.readbyqxmd.com/read/27880798/added-value-of-3d-proton-density-weighted-images-in-diagnosis-of-intracranial-arterial-dissection
#15
Jin Woo Kim, Na-Young Shin, Young Dae Kim, Seung-Koo Lee, Soo Mee Lim, Se Won Oh
BACKGROUND: An early and reliable diagnosis of intracranial arterial dissection is important to reduce the risk of neurological complication. The purpose of this study was to assess the clinical usefulness of three-dimensional high-resolution MRI (3D-HR-MRI) including pre- and post-contrast T1-weighted volumetric isotropic turbo spin echo acquisition with improved motion-sensitized driven equilibrium preparation (3D-iMSDE-T1) and proton-density weighted image (3D-PD) in detecting dissection and to evaluate the added value of 3D-PD in diagnosing intracranial arterial dissection...
2016: PloS One
https://www.readbyqxmd.com/read/27869333/patient-specific-3d-flair-for-enhanced-visualization-of-brain-white-matter-lesions-in-multiple-sclerosis
#16
Refaat E Gabr, Amol S Pednekar, Koushik A Govindarajan, Xiaojun Sun, Roy F Riascos, María G Ramírez, Khader M Hasan, John A Lincoln, Flavia Nelson, Jerry S Wolinsky, Ponnada A Narayana
PURPOSE: To improve the conspicuity of white matter lesions (WMLs) in multiple sclerosis (MS) using patient-specific optimization of single-slab 3D fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI). MATERIALS AND METHODS: Sixteen MS patients were enrolled in a prospective 3.0T MRI study. FLAIR inversion time and echo time were automatically optimized for each patient during the same scan session based on measurements of the relative proton density and relaxation times of the brain tissues...
November 21, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27856399/enhanced-laws-textures-a-potential-mri-surrogate-marker-of-hepatic-fibrosis-in-a-murine-model
#17
Baojun Li, Hernan Jara, Heishun Yu, Michael O'Brien, Jorge Soto, Stephan W Anderson
PURPOSE: To compare enhanced Laws textures derived from parametric proton density (PD) maps to other MRI surrogate markers (T2, PD, apparent diffusion coefficient (ADC)) in assessing degrees of liver fibrosis in an ex vivo murine model of hepatic fibrosis imaged using 11.7T MRI. METHODS: This animal study was IACUC approved. Fourteen male, C57BL/6 mice were divided into control and experimental groups. The latter were fed a 3,5-dicarbethoxy-1,4-dihydrocollidine (DDC) supplemented diet to induce hepatic fibrosis...
November 14, 2016: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/27856398/recovery-of-accurate-t2-from-historical-1-5-tesla-proton-density-and-t2-weighted-images-application-to-7-year-t2-changes-in-multiple-sclerosis-brain
#18
Md Nasir Uddin, Kelly C McPhee, Gregg Blevins, Alan H Wilman
OBJECTIVE: To determine accurate quantitative transverse relaxation times (T2) using retrospective clinical images and apply it to examine 7-year changes in multiple sclerosis (MS) brain. METHODS: A method for T2 mapping from retrospective proton density (PD) and T2-weighted fast spin echo images was recently introduced, but requires measurement of flip angles. We examined whether 1.5T flip angle variation in brain can be predicted, thus enabling T2 analysis of historical PD and T2-weighted images without a concurrent flip angle map...
November 14, 2016: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/27832068/time-dependent-changes-in-t1-during-fracture-healing-in-juvenile-rats-a-quantitative-mr-approach
#19
Katharina Baron, Bernhard Neumayer, Eva Amerstorfer, Eva Scheurer, Clemens Diwoky, Rudolf Stollberger, Hanna Sprenger, Annelie M Weinberg
Quantitative magnetic resonance imaging (qMRI) offers several advantages in imaging and determination of soft tissue alterations when compared to qualitative imaging techniques. Although applications in brain and muscle tissues are well studied, its suitability to quantify relaxation times of intact and injured bone tissue, especially in children, is widely unknown. The objective observation of a fracture including its age determination can become of legal interest in cases of child abuse or maltreatment. Therefore, the aim of this study is the determination of time dependent changes in intact and corresponding injured bones in immature rats via qMRI, to provide the basis for an objective and radiation-free approach for fracture dating...
2016: PloS One
https://www.readbyqxmd.com/read/27820852/osteoarthritis-in-the-knee-joints-of-g%C3%A3-ttingen-minipigs-after-resection-of-the-anterior-cruciate-ligament-missing-correlation-of-mri-gene-and-protein-expression-with-histological-scoring
#20
Gregor Reisig, Michael Kreinest, Wiltrud Richter, Mechthild Wagner-Ecker, Dietmar Dinter, Ulrike Attenberger, Barbara Schneider-Wald, Stefan Fickert, Markus L Schwarz
INTRODUCTION: The Göttingen Minipig (GM) is used as large animal model in articular cartilage research. The aim of the study was to introduce osteoarthritis (OA) in the GM by resecting the anterior cruciate ligament (ACLR) according to Pond and Nuki, verified by histological and magnetic resonance imaging (MRI) scoring as well as analysis of gene and protein expression. MATERIALS AND METHODS: The eight included skeletally mature female GM were assessed after ACLR in the left and a sham operation in the right knee, which served as control...
2016: PloS One
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