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proton density MRI

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https://www.readbyqxmd.com/read/28705058/standardized-approach-for-roi-based-measurements-of-proton-density-fat-fraction-and-r2-in-the-liver
#1
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...
July 13, 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/28702799/greater-occipital-nerve-infiltration-under-mr-guidance-feasibility-study-and-preliminary-results
#2
Adrian Kastler, Romain Perolat, Bruno Kastler, Caroline Maindet-Dominici, Jan Fritz, Alim Louis Benabid, Stephan Chabardes, Alexandre Krainik
OBJECTIVE: To assess the feasibility of greater occipital nerve (GON) intermediate site infiltration with MRI guidance. METHODS: Eleven consecutive patients suffering from chronic refractory cranio-facial pain who underwent 16 GON infiltrations were included in this prospective study. All of the procedures were performed on an outpatient basis in the research facility of our institution, with a 1.5 T scanner. The fatty space between inferior obliquus and semispinalis muscles at C1-C2 level was defined as the target...
July 12, 2017: European Radiology
https://www.readbyqxmd.com/read/28698004/the-effect-of-radiotherapy-on-fat-content-and-fatty-acids-in-myxoid-liposarcomas-quantified-by-mri
#3
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...
July 8, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28685238/functional-in-situ-assessment-of-human-articular-cartilage-using-mri-a-whole-knee-joint-loading-device
#4
Sven Nebelung, Manuel Post, Stefan Raith, Horst Fischer, Matthias Knobe, Benedikt Braun, Andreas Prescher, Markus Tingart, Johannes Thüring, Philipp Bruners, Holger Jahr, Christiane Kuhl, Daniel Truhn
The response to loading of human articular cartilage as assessed by magnetic resonance imaging (MRI) remains to be defined in relation to histology and biomechanics. Therefore, an MRI-compatible whole-knee joint loading device for the functional in situ assessment of cartilage was developed and validated in this study. A formalin-fixed human knee was scanned by computed tomography in its native configuration and digitally processed to create femoral and tibial bone models. The bone models were covered by artificial femoral and tibial articular cartilage layers in their native configuration using cartilage-mimicking polyvinyl siloxane...
July 6, 2017: Biomechanics and Modeling in Mechanobiology
https://www.readbyqxmd.com/read/28684455/identification-and-quantitative-assessment-of-different-components-of-intracranial-atherosclerotic-plaque-by-ex-vivo-3t-high-resolution-multicontrast-mri
#5
Y Jiang, W Peng, B Tian, C Zhu, L Chen, X Wang, Q Liu, Y Wang, Z Xiang, A J Degnan, Z Teng, D Saloner, J Lu
BACKGROUND AND PURPOSE: High-resolution 3T MR imaging can visualize intracranial atherosclerotic plaque. However, histologic validation is still lacking. This study aimed to evaluate the ability of 3T MR imaging to identify and quantitatively assess intracranial atherosclerotic plaque components ex vivo with histologic validation. MATERIALS AND METHODS: Fifty-three intracranial arterial specimens with atherosclerotic plaques from 20 cadavers were imaged by 3T MR imaging with T1, T2, and proton-density-weighted FSE and STIR sequences...
July 6, 2017: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/28673882/evaluating-g-ratio-weighted-changes-in-the-corpus-callosum-as-a-function-of-age-and-sex
#6
REVIEW
Shai Berman, Kathryn L West, Mark D Does, Jason D Yeatman, Aviv A Mezer
Recent years have seen a growing interest in relating MRI measurements to the structural-biophysical properties of white matter fibers. The fiber g-ratio, defined as the ratio between the inner and outer radii of the axon myelin sheath, is an important structural property of white matter, affecting signal conduction. Recently proposed modeling methods that use a combination of quantitative-MRI signals, enable a measurement of the fiber g-ratio in vivo. Here we use an MRI-based g-ratio estimation to observe the variance of the g-ratio within the corpus callosum, and evaluate sex and age related differences...
June 30, 2017: NeuroImage
https://www.readbyqxmd.com/read/28668358/a-new-algebraic-method-for-quantitative-proton-density-mapping-using-multi-channel-coil-data
#7
Dietmar Cordes, Zhengshi Yang, Xiaowei Zhuang, Karthik Sreenivasan, Virendra Mishra, Le H Hua
A difficult problem in quantitative MRI is the accurate determination of the proton density, which is an important quantity in measuring brain tissue organization. Recent progress in estimating proton density in vivo has been based on using the inverse linear relationship between the longitudinal relaxation rate T1 and proton density. In this study, the same type of relationship is being used, however, in a more general framework by constructing 3D basis functions to model the receiver bias field. The novelty of this method is that the basis functions developed are suitable to cover an entire range of inverse linearities between T1 and proton density...
June 23, 2017: Medical Image Analysis
https://www.readbyqxmd.com/read/28658878/role-of-mri-in-a-series-of-cases-with-biceps-injuries-of-the-shoulder
#8
Abhishek Dwivedi, P K Dhagat, S N Singh, Shalini Singh, Narender Yadav
Dislocation and injury of the biceps is associated with acute and chronic trauma, degenerative changes, repetitive microtrauma, or injuries associated with recurrent and neglected cases of shoulder dislocation. The cases of displaced biceps injuries are relatively rare (only 1/6(th) of all rotator cuff injuries). The dislocation of biceps is manifested with pain and restriction of movements. The X-ray shoulder is not of much help in this condition barring for ruling out the fractures of humerus and scapula...
May 2017: Journal of Clinical and Diagnostic Research: JCDR
https://www.readbyqxmd.com/read/28643359/an-open-8-channel-parallel-transmission-coil-for-static-and-dynamic-7t-mri-of-the-knee-and-ankle-joints-at-multiple-postures
#9
Jin Jin, Ewald Weber, Aurelien Destruel, Kieran O'Brien, Bassem Henin, Craig Engstrom, Stuart Crozier
PURPOSE: We present the initial in vivo imaging results of an open architecture eight-channel parallel transmission (pTx) transceive radiofrequency (RF) coil array that was designed and constructed for static and dynamic 7T MRI of the knee and ankle joints. METHODS: The pTx coil has a U-shaped dual-row configuration (200 mm overall length longitudinally) that allows static and dynamic imaging of the knee and ankle joints at various postures and during active movements...
June 22, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28628033/nonalcoholic-fatty-liver-disease-with-cirrhosis-increases-familial-risk-for-advanced-fibrosis
#10
Cyrielle Caussy, Meera Soni, Jeffrey Cui, Ricki Bettencourt, Nicholas Schork, Chi-Hua Chen, Mahdi Al Ikhwan, Shirin Bassirian, Sandra Cepin, Monica P Gonzalez, Michel Mendler, Yuko Kono, Irine Vodkin, Kristin Mekeel, Jeffrey Haldorson, Alan Hemming, Barbara Andrews, Joanie Salotti, Lisa Richards, David A Brenner, Claude B Sirlin, Rohit Loomba
BACKGROUND: The risk of advanced fibrosis in first-degree relatives of patients with nonalcoholic fatty liver disease and cirrhosis (NAFLD-cirrhosis) is unknown and needs to be systematically quantified. We aimed to prospectively assess the risk of advanced fibrosis in first-degree relatives of probands with NAFLD-cirrhosis. METHODS: This is a cross-sectional analysis of a prospective cohort of 26 probands with NAFLD-cirrhosis and 39 first-degree relatives. The control population included 69 community-dwelling twin, sib-sib, or parent-offspring pairs (n = 138), comprising 69 individuals randomly ascertained to be without evidence of NAFLD and 69 of their first-degree relatives...
June 30, 2017: Journal of Clinical Investigation
https://www.readbyqxmd.com/read/28626099/-a-cross-sectional-study-on-the-correlation-between-mri-signal-for-ipfp-and-knee-osteoarthritis
#11
Song Wu, Hongliang Ba, Jinshen He, Yunjie Liao
To investigate the correlation between MRI signal for infrapatellar fat pad (IPFP) and pathological changes in knee osteoarthritis (KOA), and to analyze the role of IPFP in the development of knee osteoarthritis.
 Methods: A total of 114 subjects (without special knee disease) were enrolled for this study. The intensity of MRI signal for IPFP was determined by fat-suppressed proton-density-weighted turbospin-echo magnetic resonance imaging. Based on the cartilage defects and osteophytes of knee joint, the subjects were divided into a KOA group and a control group...
May 28, 2017: Zhong Nan da Xue Xue Bao. Yi Xue Ban, Journal of Central South University. Medical Sciences
https://www.readbyqxmd.com/read/28624986/temperature-corrected-post-mortem-1-5%C3%A2-t-mri-quantification-of-non-pathologic-upper-abdominal-organs
#12
Nicole Schwendener, Christian Jackowski, Frederick Schuster, Anders Persson, Marcel J Warntjes, Wolf -Dieter Zech
OBJECTIVES: The present study aimed to evaluate if simultaneous temperature-corrected T1, T2, and proton density (PD) 1.5 T post-mortem MR quantification [quantitative post-mortem magnetic resonance imaging (QPMMRI)] is feasible for characterizing and discerning non-pathologic upper abdominal organs (liver, spleen, pancreas, kidney) with regard to varying body temperatures. METHODS: QPMMRI was performed on 80 corpses (25 females, 55 males; mean age 56.2 years, SD 17...
June 17, 2017: International Journal of Legal Medicine
https://www.readbyqxmd.com/read/28624576/agreement-between-magnetic-resonance-imaging-proton-density-fat-fraction-measurements-and-pathologist-assigned-steatosis-grades-of-liver-biopsies-from-adults-with-nonalcoholic-steatohepatitis
#13
Michael S Middleton, Elhamy R Heba, Catherine A Hooker, Mustafa R Bashir, Kathryn J Fowler, Kumar Sandrasegaran, Elizabeth M Brunt, David E Kleiner, Edward Doo, Mark L Van Natta, James Tonascia, Joel E Lavine, Brent A Neuschwander-Tetri, Arun Sanyal, Rohit Loomba, Claude B Sirlin
BACKGROUND & AIMS: We assessed the diagnostic performance of magnetic resonance imaging (MRI) proton density fat fraction (PDFF) in grading hepatic steatosis and change in hepatic steatosis in adults with nonalcoholic steatohepatitis (NASH) in a multi-center study, using central histology as reference. METHODS: We collected data from 113 adults with NASH participating in a multi-center, randomized, double-masked, placebo-controlled, phase 2b trial to compare the efficacy cross-sectionally and longitudinally of obeticholic acid vs placebo...
June 15, 2017: Gastroenterology
https://www.readbyqxmd.com/read/28589660/simultaneous-quantification-of-bone-edema-adiposity-and-structure-in-inflamed-bone-using-chemical-shift-encoded-mri-in-spondyloarthritis
#14
Timothy J P Bray, Alan Bainbridge, Shonit Punwani, Yiannis Ioannou, Margaret A Hall-Craggs
PURPOSE: To evaluate proton density fat fraction (PDFF) and R2* as markers of bone marrow composition and structure in inflamed bone in patients with spondyloarthritis. METHODS: Phantoms containing fat, water, and trabecular bone were constructed with proton density fat fraction (PDFF) and bone mineral density (BMD) values matching those expected in healthy bone marrow and disease states, and scanned using chemical shift-encoded MRI (CSE-MRI) at 3T. Measured PDFF and R2* values in phantoms were compared with reference FF and BMD values...
June 6, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28576701/relevance-of-mri-for-management-of-non-displaced-lateral-humeral-condyle-fractures-in-children
#15
C Thévenin-Lemoine, S Salanne, T Pham, F Accadbled, C Baunin, J Sales De Gauzy
INTRODUCTION: The treatment for non-displaced (<2 mm displacement) fractures of the lateral humeral condyle in children is controversial. Most studies recommend non-surgical treatment. However, plain radiographs are not sufficient to evaluate extension of the fracture line through the articular cartilage. This explains the high frequency of secondary displacements and non-unions, despite well-conducted conservative treatment. We hypothesized that MRI could be used to analyse whether the fracture is complete or incomplete...
May 30, 2017: Orthopaedics & Traumatology, Surgery & Research: OTSR
https://www.readbyqxmd.com/read/28550649/improved-formula-see-text-determination-in-23-na-35-cl-and-17-o-mri-using-iterative-partial-volume-correction-based-on-1-h-mri-segmentation
#16
Sebastian C Niesporek, Reiner Umathum, Thomas M Fiedler, Peter Bachert, Mark E Ladd, Armin M Nagel
OBJECTIVE: Functional parameters can be measured with the help of quantitative non-proton MRI where exact relaxometry parameters are needed. Investigation of [Formula: see text] is often biased by strong partial volume (PV) effects. Hence, in this work a PV correction algorithm approach was evaluated that uses iteratively adapted [Formula: see text]-values and high-resolution structural (1)H data to determine transverse relaxation in non-proton MRI more accurately. MATERIALS AND METHODS: Simulations, a phantom study and in vivo (23)Na, (17)O and (35)Cl MRI measurements of five healthy volunteers were performed to evaluate the algorithm...
May 26, 2017: Magma
https://www.readbyqxmd.com/read/28543915/cross-sectional-correlation-between-hepatic-r2-and-proton-density-fat-fraction-pdff-in-children-with-hepatic-steatosis
#17
Adrija Mamidipalli, Gavin Hamilton, Paul Manning, Cheng William Hong, Charlie C Park, Tanya Wolfson, Jonathan Hooker, Elhamy Heba, Alexandra Schlein, Anthony Gamst, Janis Durelle, Melissa Paiz, Michael S Middleton, Jeffrey B Schwimmer, Claude B Sirlin
PURPOSE: To determine the relationship between hepatic proton density fat fraction (PDFF) and R2* in vivo. MATERIALS AND METHODS: In this Health Insurance Portability and Accountability Act (HIPAA)-compliant, Institutional Review Board (IRB)-approved, cross-sectional study, we conducted a secondary analysis of 3T magnetic resonance imaging (MRI) exams performed as part of prospective research studies in children in whom conditions associated with iron overload were excluded clinically...
May 25, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28542553/quantitative-mri-for-analysis-of-peritumoral-edema-in-malignant-gliomas
#18
Ida Blystad, J B Marcel Warntjes, Örjan Smedby, Peter Lundberg, Elna-Marie Larsson, Anders Tisell
BACKGROUND AND PURPOSE: Damage to the blood-brain barrier with subsequent contrast enhancement is a hallmark of glioblastoma. Non-enhancing tumor invasion into the peritumoral edema is, however, not usually visible on conventional magnetic resonance imaging. New quantitative techniques using relaxometry offer additional information about tissue properties. The aim of this study was to evaluate longitudinal relaxation R1, transverse relaxation R2, and proton density in the peritumoral edema in a group of patients with malignant glioma before surgery to assess whether relaxometry can detect changes not visible on conventional images...
2017: PloS One
https://www.readbyqxmd.com/read/28520813/pancreatic-fat-content-by-magnetic-resonance-imaging-in-subjects-with-prediabetes-diabetes-and-controls-from-a-general-population-without-cardiovascular-disease
#19
Sophia D Heber, Holger Hetterich, Roberto Lorbeer, Christian Bayerl, Jürgen Machann, Sigrid Auweter, Corinna Storz, Christopher L Schlett, Konstantin Nikolaou, Maximilian Reiser, Annette Peters, Fabian Bamberg
BACKGROUND/OBJECTIVE: Despite the relevance of pancreatic fat content in the development of metabolic diseases, its association with impaired glucose metabolism, diabetes, and other adipose tissue compartments remains unclear. Thus, we determined differences in pancreatic fat content by magnetic resonance imaging (MRI) between subjects with prediabetes, diabetes, and normal controls in a cohort from the general population. METHODS: Subjects without history of cardiovascular disease with established diabetes or prediabetes as well as normal controls were included and underwent whole-body MRI on a 3T scanner...
2017: PloS One
https://www.readbyqxmd.com/read/28520778/texture-analysis-using-proton-density-and-t2-relaxation-in-patients-with-histological-usual-interstitial-pneumonia-uip-or-nonspecific-interstitial-pneumonia-nsip
#20
Maria T A Buzan, Andreas Wetscherek, Claus Peter Heussel, Michael Kreuter, Felix J Herth, Arne Warth, Hans-Ulrich Kauczor, Carmen Monica Pop, Julien Dinkel
OBJECTIVES: The purpose of our study was to assess proton density (PD) and T2 relaxation time of usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP) and to evaluate their utility in differentiating the two patterns. Furthermore, we aim to investigate whether these two parameters could help differentiate active-inflammatory and stable-fibrotic lesions in NSIP. METHODS: 32 patients (mean age: 69 years; M:F, 1:1) with pathologically proven disease (UIP:NSIP, 1:1), underwent thoracic thin-section multislice CT scan and 1...
2017: PloS One
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