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proton density MRI

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https://www.readbyqxmd.com/read/28913930/accuracy-repeatability-and-interplatform-reproducibility-of-t1-quantification-methods-used-for-dce-mri-results-from-a-multicenter-phantom-study
#1
Octavia Bane, Stefanie J Hectors, Mathilde Wagner, Lori L Arlinghaus, Madhava P Aryal, Yue Cao, Thomas L Chenevert, Fiona Fennessy, Wei Huang, Nola M Hylton, Jayashree Kalpathy-Cramer, Kathryn E Keenan, Dariya I Malyarenko, Robert V Mulkern, David C Newitt, Stephen E Russek, Karl F Stupic, Alina Tudorica, Lisa J Wilmes, Thomas E Yankeelov, Yi-Fei Yen, Michael A Boss, Bachir Taouli
PURPOSE: To determine the in vitro accuracy, test-retest repeatability, and interplatform reproducibility of T1 quantification protocols used for dynamic contrast-enhanced MRI at 1.5 and 3 T. METHODS: A T1 phantom with 14 samples was imaged at eight centers with a common inversion-recovery spin-echo (IR-SE) protocol and a variable flip angle (VFA) protocol using seven flip angles, as well as site-specific protocols (VFA with different flip angles, variable repetition time, proton density, and Look-Locker inversion recovery)...
September 14, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28895045/influence-of-gd-eob-dtpa-on-proton-density-fat-fraction-using-the-six-echo-dixon-method-in-3-tesla-magnetic-resonance-imaging
#2
Tatsuya Hayashi, Kei Fukuzawa, Hiroshi Kondo, Hiroshi Onodera, Shuji Toyotaka, Rie Tojo, Shimpei Yano, Masakatsu Tano, Tosiaki Miyati, Jun'ichi Kotoku, Takahide Okamoto, Keiko Toyoda, Hiroshi Oba
The purpose of this study was to evaluate whether disodium gadoxetate (Gd-EOB-DTPA) affects proton density fat fractions (PDFFs) during use of the multiecho Dixon (meDixon) method in phantom and simulation magnetic resonance imaging (MRI) studies at 3 T. Fat-water phantoms comprising vegetable fat-water emulsions with varying fat volume percentages (0, 5, 10, 15, 20, 30, 40, and 50) and Gd-EOB-DTPA concentrations (0 and 0.4 mM) were prepared. Phantoms without Gd-EOB-DTPA were defined as precontrast, and those with Gd-EOB-DTPA were defined as postcontrast...
September 11, 2017: Radiological Physics and Technology
https://www.readbyqxmd.com/read/28894290/association-of-proton-density-fat-fraction-in-adipose-tissue-with-imaging-based-and-anthropometric-obesity-markers-in-adults
#3
D Franz, D Weidlich, F Freitag, C Holzapfel, T Drabsch, T Baum, H Eggers, A Witte, E J Rummeny, H Hauner, D C Karampinos
BACKGROUND/OBJECTIVES: The purpose of this study was to examine the relationship of the proton density fat fraction (PDFF), measured by magnetic resonance imaging (MRI), of supraclavicular and gluteal adipose tissue with subcutaneous and visceral adipose tissue (SAT and VAT) volumes, liver fat fraction and anthropometric obesity markers. The supraclavicular fossa was selected as a typical location where brown adipocytes may be present in humans and the gluteal region was selected as a typical location enclosing primarily white adipocytes...
August 14, 2017: International Journal of Obesity: Journal of the International Association for the Study of Obesity
https://www.readbyqxmd.com/read/28881536/-mr-imaging-of-flexor-tendon-and-pulley-system-of-the-fingers-normal-anatomy-and-injury
#4
R J Bai, H L Zhan, Y Liu, H Zhang, Z H Qian, W Ye, Y X Li
Objective: To explore the magnetic resonance imaging (MRI) features of the anatomy and injuries of flexor tendon and pulley system of the fingers. Methods: Clinical and imaging data of 20 healthy volunteers without injuries and 36 patients from Beijing Jishuitan Hospital with flexor tendon and pulley system injuries in the fingers between March 2013 and March 2016 were retrospectively analyzed. All subjects underwent magnetic resonance imaging (MRI) examination. The MRI findings of patients were compared with healthy volunteers...
September 5, 2017: Zhonghua Yi Xue za Zhi [Chinese medical journal]
https://www.readbyqxmd.com/read/28870515/mri-characteristics-of-the-glia-limitans-externa-a-7t-study
#5
Kiyotaka Suzuki, Kenichi Yamada, Kazunori Nakada, Yuji Suzuki, Masaki Watanabe, Ingrid L Kwee, Tsutomu Nakada
PURPOSE: To perform a systematic analysis of the intrinsic contrast parameters of the FLAIR hyperintense rim (FHR), a thin layer of high intensity covering the entire surface of the cerebral cortex detected on fluid-attenuated inversion recovery (FLAIR) sequence T2 weighted imaging performed on a 7T system, in an attempt to identify its anatomical correlate. METHODS: Fast spin echo inversion recovery (FSE-IR) and cardiac-gated fast spin echo (FSE) images were obtained with defined parameters in eight normal volunteers on a 7 T MRI system to determine T2 and proton density, T1 characteristics...
September 9, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28869162/a-novel-method-for-t2-quantification-in-presence-of-b1-inhomogeneities
#6
David Milford, Martin Bendszus, Sabine Heiland
INTRODUCTION: T2 relaxometry as a quantitative MRI technique offers a more precise characterization of tissue, compared with qualitative T2 weighted imaging. The issue, however, is that in typically used T2 relaxometry sequences such as a multi-spin echo sequences, incorrect refocussing flip angles and B1 inhomogeneities cause inaccuracies in T2 determination. The work presented here within presents a new technique for modelling T2 decay curves and thereby correcting T2 times altered by inhomogeneities...
August 28, 2017: Zeitschrift Für Medizinische Physik
https://www.readbyqxmd.com/read/28865431/uncommon-presentation-of-a-rare-tumour-incidental-finding-in-an-asymptomatic-patient-case-report-and-comprehensive-review-of-the-literature-on-intrapericardial-solitary-fibrous-tumours
#7
Csilla Czimbalmos, Ibolya Csecs, Miklos Polos, Elektra Bartha, Nikolette Szucs, Attila Toth, Pal Maurovich-Horvat, David Becker, Zoltan Sapi, Zoltan Szabolcs, Bela Merkely, Hajnalka Vago
BACKGROUND: A solitary fibrous tumour is a rare, mainly benign spindle cell mesenchymal tumour most commonly originating from the pleura. An intrapericardial location of a solitary fibrous tumour is extremely unusual. We present a case of an asymptomatic patient with a slow-growing massive benign cardiac solitary fibrous tumour. CASE PRESENTATION: A 37-year-old asymptomatic female patient was referred to our hospital with an enlarged cardiac silhouette found on her screening chest X-ray...
September 2, 2017: BMC Cancer
https://www.readbyqxmd.com/read/28842937/optimization-of-region-of-interest-sampling-strategies-for-hepatic-mri-proton-density-fat-fraction-quantification
#8
Cheng William Hong, Tanya Wolfson, Ethan Z Sy, Alexandra N Schlein, Jonathan C Hooker, Soudabeh Fazeli Dehkordy, Gavin Hamilton, Scott B Reeder, Rohit Loomba, Claude B Sirlin
BACKGROUND: Clinical trials utilizing proton density fat fraction (PDFF) as an imaging biomarker for hepatic steatosis have used a laborious region-of-interest (ROI) sampling strategy of placing an ROI in each hepatic segment. PURPOSE: To identify a strategy with the fewest ROIs that consistently achieves close agreement with the nine-ROI strategy. STUDY TYPE: Retrospective secondary analysis of prospectively acquired clinical research data...
August 26, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28833436/fast-3d-magnetic-resonance-fingerprinting-for-a-whole-brain-coverage
#9
Dan Ma, Yun Jiang, Yong Chen, Debra McGivney, Bhairav Mehta, Vikas Gulani, Mark Griswold
PURPOSE: The purpose of this study was to accelerate the acquisition and reconstruction time of 3D magnetic resonance fingerprinting scans. METHODS: A 3D magnetic resonance fingerprinting scan was accelerated by using a single-shot spiral trajectory with an undersampling factor of 48 in the x-y plane, and an interleaved sampling pattern with an undersampling factor of 3 through plane. Further acceleration came from reducing the waiting time between neighboring partitions...
August 22, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28830272/bone-morphological-factors-influencing-cartilage-degeneration-in-the-knee
#10
Kenji Takahashi, Sanshiro Hashimoto, Shinji Kiuchi, Atsuya Watanabe, Hiroshi Nakamura, Futoshi Ikuta, Tomoyuki Okuaki, Tatsunori Kataoka, Tokifumi Majima, Shinro Takai
OBJECTIVES: Morphological features of the distal femur and proximal tibia associated with cartilage degeneration are unknown. This study aimed to elucidate local anatomical parameters of the knee which correlate with articular cartilage degeneration using MRI T1ρ mapping. METHODS: This study involved 200 subjects with knee pain (mean age, 48.7 years; range, 14-80 years) with no severe osteoarthritic changes on plain X-ray. T1ρ values were measured in the regions of interest on the surface layer of the cartilage on mid-coronal images of the femorotibial joint...
August 23, 2017: Modern Rheumatology
https://www.readbyqxmd.com/read/28826288/characteristic-mr-findings-suggesting-presumed-labyrinthine-hemorrhage
#11
Dong Sun Kim, Dong Woo Park, Tae Yoon Kim, Sang Joon Lee, Young-Jun Lee, Ji Young Lee, Seung Hwan Lee, Jae Ho Chung
OBJECTIVES: To evaluate the magnetic resonance imaging (MRI) findings of labyrinthine hemorrhage as a cause of sudden sensorineural hearing loss (SSNHL). METHODS: MRI scans of 59 patients with SSNHL were retrospectively analyzed and compared to clinical features and audiometry data. MR images included pre-enhanced T1-weighted, 3D FLAIR VISTA, post-enhanced T1-weighted and 4-h-delayed enhanced FLAIR volume isometric turbo spin-echo acquisition (VISTA), and 3D thin-section proton density-weighted images...
August 21, 2017: Acta Oto-laryngologica
https://www.readbyqxmd.com/read/28816961/estimating-of-hepatic-fat-amount-using-mri-proton-density-fat-fraction-in-a-real-practice-setting
#12
RANDOMIZED CONTROLLED TRIAL
Hyeyoung Lee, Dae Won Jun, Bo-Kyeong Kang, Eunwoo Nam, Misoo Chang, Mimi Kim, Soonyoung Song, Byung Chul Yoon, Hang Lak Lee, Oh Young Lee, Ho Soon Choi, Kang Nyeong Lee
The recently developed magnetic resonance imaging (MRI) proton density fat fraction (PDFF) allows measurement of the fat in all segments of hepatic tissue. However, it is time consuming and inconvenient to measure each segment repeatedly. Moreover, volume of each segment also should be adjusted with arithmetic mean of the selected segments when total amount of liver fat is estimated. Therefore, we try to develop a clinically-relevant and applicable method of estimating hepatic fat in PDFF image.A total of 164 adults were enrolled...
August 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28801212/intraoperative-validation-of-quantitative-t2-mapping-in-patients-with-articular-cartilage-lesions-of-the-knee
#13
S Soellner, A Goldmann, D Muelheims, G H Welsch, M Pachowsky
OBJECTIVE: The aim of this study was to compare T2 relaxation times of knee cartilage with intraoperative results for the assessment of early osteoarthritis (OA) and to define T2 values for the differentiation between healthy and degenerated cartilage. DESIGN: Twenty-one patients with cartilage lesions or moderate OA were examined using 3T magnetic resonance imaging (MRI). In this prospective study, a total of 882 regions of interest (ROIs) were examined by a sagittal, multi-echo, spin-echo T2 sequence and a morphological high-resolution three-dimensional, fat-saturated proton-density space sequence...
August 8, 2017: Osteoarthritis and Cartilage
https://www.readbyqxmd.com/read/28790406/the-diagnostic-accuracy-of-magnetic-resonance-imaging-for-anterior-cruciate-ligament-injury-in-comparison-to-arthroscopy-a-meta-analysis
#14
Kun Li, Jun Du, Li-Xin Huang, Li Ni, Tao Liu, Hui-Lin Yang
We performed this meta-analysis to examine the diagnostic accuracy of MRI for the diagnosis of anterior cruciate ligament (ACL) injury in comparison to arthroscopy. We also compared the diagnostic accuracy of MRI with magnetic field intensities (MFI) greater than or equal to 1.5T with those below 1.5T, in addition to different MRI sequences. Studies relevant to the diagnosis of ACL injury by MRI and arthroscopy were analyzed. Computer and manual retrieval were carried out on studies published between January 1, 2006 and May 31, 2016...
August 8, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28751202/r1%C3%AF-dispersion-and-sodium-imaging-in-human-calf-muscle
#15
Ping Wang, He Zhu, Hakmook Kang, John C Gore
PURPOSE: To evaluate the magnitude of chemical exchange effects and R1ρ dispersion in muscle and their relationship to tissue sodium levels with aging. METHODS: Seven healthy volunteers (aged 24 to 87years, median age 47) underwent MRI to assess tissue sodium levels and water T1ρ values at different spin-locking frequencies in calf muscles. T1ρ values at each locking field were computed based on a three-parameter mono-exponential model to fit signals obtained at different locking times, and R1ρ (=1/T1ρ) rates were compared at different locking fields...
July 24, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28748393/the-validate29-mri-based-multi-channel-atlas-of-the-squirrel-monkey-brain
#16
Kurt G Schilling, Yurui Gao, Iwona Stepniewska, Tung-Lin Wu, Feng Wang, Bennett A Landman, John C Gore, Li Min Chen, Adam W Anderson
We describe the development of the first digital atlas of the normal squirrel monkey brain and present the resulting product, VALiDATe29. The VALiDATe29 atlas is based on multiple types of magnetic resonance imaging (MRI) contrast acquired on 29 squirrel monkeys, and is created using unbiased, nonlinear registration techniques, resulting in a population-averaged stereotaxic coordinate system. The atlas consists of multiple anatomical templates (proton density, T1, and T2* weighted), diffusion MRI templates (fractional anisotropy and mean diffusivity), and ex vivo templates (fractional anisotropy and a structural MRI)...
July 26, 2017: Neuroinformatics
https://www.readbyqxmd.com/read/28705058/standardized-approach-for-roi-based-measurements-of-proton-density-fat-fraction-and-r2-in-the-liver
#17
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
#18
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
#19
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
#20
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
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