keyword
MENU ▼
Read by QxMD icon Read
search

proton density MRI

keyword
https://www.readbyqxmd.com/read/28432504/3t-mri-of-the-knee-with-optimised-isotropic-3d-sequences-accurate-delineation-of-intra-articular-pathology-without-prolonged-acquisition-times
#1
Osamah M Abdulaal, Louise Rainford, Peter MacMahon, Eoin Kavanagh, Marie Galligan, James Cashman, Allison McGee
OBJECTIVES: To investigate optimised isotropic 3D turbo spin echo (TSE) and gradient echo (GRE)-based pulse sequences for visualisation of articular cartilage lesions within the knee joint. METHODS: Optimisation of experimental imaging sequences was completed using healthy volunteers (n=16) with a 3-Tesla (3T) MRI scanner. Imaging of patients with knee cartilage abnormalities (n=57) was then performed. Acquired sequences included 3D proton density-weighted (PDW) TSE (SPACE) with and without fat-suppression (FS), and T2*W GRE (TrueFISP) sequences, with acquisition times of 6:51, 6:32 and 5:35 min, respectively...
April 21, 2017: European Radiology
https://www.readbyqxmd.com/read/28432403/bone-marrow-fat-content-in-70-adolescent-girls-with-anorexia-nervosa-magnetic-resonance-imaging-and-magnetic-resonance-spectroscopy-assessment
#2
Kirsten Ecklund, Sridhar Vajapeyam, Robert V Mulkern, Henry A Feldman, Jennifer M O'Donnell, Amy D DiVasta, Catherine M Gordon
BACKGROUND: Adolescents and women with anorexia nervosa have increased bone marrow fat and decreased bone formation, at least in part due to hormonal changes leading to preferential stem cell differentiation to adipocytes over osteoblasts. OBJECTIVE: The purpose of this study was to evaluate marrow fat content and correlate with age and disease severity using knee MRI with T1 relaxometry (T1-R) and MR spectroscopy (MRS) in 70 adolescents with anorexia nervosa. MATERIALS AND METHODS: We enrolled 70 girls with anorexia nervosa who underwent 3-T knee MRI with coronal T1-W images, T1-R and single-voxel proton MRS at 30 and 60 ms TE...
April 22, 2017: Pediatric Radiology
https://www.readbyqxmd.com/read/28419582/free-breathing-liver-fat-quantification-using-a-multiecho-3d-stack-of-radial-technique
#3
Tess Armstrong, Isabel Dregely, Alto Stemmer, Fei Han, Yutaka Natsuaki, Kyunghyun Sung, Holden H Wu
PURPOSE: The diagnostic gold standard for nonalcoholic fatty liver disease is an invasive biopsy. Noninvasive Cartesian MRI fat quantification remains limited to a breath-hold (BH). In this work, a novel free-breathing 3D stack-of-radial (FB radial) liver fat quantification technique is developed and evaluated in a preliminary study. METHODS: Phantoms and healthy subjects (n = 11) were imaged at 3 Tesla. The proton-density fat fraction (PDFF) determined using FB radial (with and without scan acceleration) was compared to BH single-voxel MR spectroscopy (SVS) and BH 3D Cartesian MRI using linear regression (correlation coefficient ρ and concordance coefficient ρc ) and Bland-Altman analysis...
April 16, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28416450/denoise-diffusion-weighted-images-using-higher-order-singular-value-decomposition
#4
Xinyuan Zhang, Jie Peng, Man Xu, Wei Yang, Zhe Zhang, Hua Guo, Wufan Chen, Qianjin Feng, Ed X Wu, Yanqiu Feng
Noise usually affects the reliability of quantitative analysis in diffusion-weighted (DW) magnetic resonance imaging (MRI), especially at high b-values and/or high spatial resolution. Higher-order singular value decomposition (HOSVD) has recently emerged as a simple, effective, and adaptive transform to exploit sparseness within multidimensional data. In particular, the patch-based HOSVD denoising has demonstrated superb performance when applied to T1-, T2-, and proton density-weighted MRI data. In this study, we aim to investigate the feasibility of denoising DW data using the HOSVD transform...
April 14, 2017: NeuroImage
https://www.readbyqxmd.com/read/28411157/the-separate-effects-of-lipids-and-proteins-on-brain-mri-contrast-revealed-through-tissue-clearing
#5
Christoph Leuze, Markus Aswendt, Emily Ferenczi, Corey W Liu, Brian Hsueh, Maged Goubran, Qiyuan Tian, Gary Steinberg, Michael M Zeineh, Karl Deisseroth, Jennifer A McNab
Despite the widespread use of magnetic resonance imaging (MRI) of the brain, the relative contribution of different biological components (e.g. lipids and proteins) to structural MRI contrasts (e.g., T1, T2, T2*, proton density, diffusion) remains incompletely understood. This limitation can undermine the interpretation of clinical MRI and hinder the development of new contrast mechanisms. Here, we determine the respective contribution of lipids and proteins to MRI contrast by removing lipids and preserving proteins in mouse brains using CLARITY...
April 12, 2017: NeuroImage
https://www.readbyqxmd.com/read/28390542/comparison-of-in%C3%A2-vivo-vs-frozen-vs-thiel-cadaver-specimens-in-visualisation-of-anatomical-structures-of-the-ankle-on-proton-density-magnetic-resonance-imaging-mri-through-a-visual-grading-analysis-vga-study
#6
F Zarb, J McNulty, A Gatt, C Formosa, N Chockalingam, M G Evanoff, L Rainford
PURPOSE: The use of cadavers for medical education purposes and for radiology research methodologies which involve subjective image quality evaluation of anatomical criteria is well documented. The aim of this study was to quantify the impact of cadaver tissue preservation in producing MR images that are representative of living tissue by comparing the visualisation of anatomical structures of the ankle obtained from live and cadaver (fresh frozen and Thiel embalmed) specimens through a visual grading analysis (VGA) study...
May 2017: Radiography
https://www.readbyqxmd.com/read/28382554/measurement-of-vertebral-bone-marrow-proton-density-fat-fraction-in-children-using-quantitative-water-fat-mri
#7
Stefan Ruschke, Amber Pokorney, Thomas Baum, Holger Eggers, Jeffrey H Miller, Houchun H Hu, Dimitrios C Karampinos
OBJECTIVES: To investigate the feasibility of employing a 3D time-interleaved multi-echo gradient-echo (TIMGRE) sequence to measure the proton density fat fraction (PDFF) in the vertebral bone marrow (VBM) of children and to examine cross-sectional changes with age and intra-individual variations from the lumbar to the cervical region in the first two decades of life. MATERIALS AND METHODS: Quantitative water-fat imaging of the spine was performed in 93 patients (49 girls; 44 boys; age median 4...
April 5, 2017: Magma
https://www.readbyqxmd.com/read/28345546/high-resolution-3t-magnetic-resonance-imaging-of-the-triangular-fibrocartilage-complex-in-chinese-wrists-correlation-with-cross-sectional-anatomy
#8
Hui-Li Zhan, Wen-Ting Li, Rong-Jie Bai, Nai-Li Wang, Zhan-Hua Qian, Wei Ye, Yu-Ming Yin
BACKGROUND: The injury of the triangular fibrocartilage complex (TFCC) is a common cause of ulnar-sided wrist pain. The aim of this study was to investigate if the high-resolution 3T magnetic resonance imaging (MRI) could demonstrate the detailed complex anatomy of TFCC in Chinese. METHODS: Fourteen Chinese cadaveric wrists (from four men and three women; age range at death from 30 to 60 years; mean age at 46 years) and forty healthy Chinese wrists (from 20 healthy volunteers, male/female: 10/10; age range from 21 to 53 years with a mean age of 32 years) in Beijing Jishuitan Hospital from March 2014 to March 2016 were included in this study...
April 5, 2017: Chinese Medical Journal
https://www.readbyqxmd.com/read/28337412/differential-involvement-of-corticospinal-tract-cst-fibers-in-umn-predominant-als-patients-with-or-without-cst-hyperintensity-a-diffusion-tensor-tractography-study
#9
Venkateswaran Rajagopalan, Erik P Pioro
Diagnosis of amyotrophic lateral sclerosis (ALS) depends on clinical evidence of combined upper motor neuron (UMN) and lower motor neuron (LMN) degeneration, although ALS patients can present with features predominantly of one or the other. Some UMN-predominant patients show hyperintense signal along the intracranial corticospinal tract (CST) on T2- and proton density (PD)-weighted images (ALS-CST +), and appear to have faster disease progression when compared to those without CST hyperintensity (ALS-CST -)...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28332039/combined-quantification-of-fatty-infiltration-t-1-relaxation-times-and-t-2-relaxation-times-in-normal-appearing-skeletal-muscle-of-controls-and-dystrophic-patients
#10
Benjamin Leporq, Arnaud Le Troter, Yann Le Fur, Emmanuelle Salort-Campana, Maxime Guye, Olivier Beuf, Shahram Attarian, David Bendahan
OBJECTIVES: To evaluate the combination of a fat-water separation method with an automated segmentation algorithm to quantify the intermuscular fatty-infiltrated fraction, the relaxation times, and the microscopic fatty infiltration in the normal-appearing muscle. MATERIALS AND METHODS: MR acquisitions were performed at 1.5T in seven patients with facio-scapulo-humeral dystrophy and eight controls. Disease severity was assessed using commonly used scales for the upper and lower limbs...
March 22, 2017: Magma
https://www.readbyqxmd.com/read/28328013/validation-of-surface-to-volume-ratio-measurements-derived-from-oscillating-gradient-spin-echo-on-a-clinical-scanner-using-anisotropic-fiber-phantoms
#11
Gregory Lemberskiy, Steven H Baete, Martijn A Cloos, Dmitry S Novikov, Els Fieremans
A diffusion measurement in the short-time surface-to-volume ratio (S/V) limit (Mitra et al., Phys Rev Lett. 1992;68:3555) can disentangle the free diffusion coefficient from geometric restrictions to diffusion. Biophysical parameters, such as the S/V of tissue membranes, can be used to estimate microscopic length scales non-invasively. However, due to gradient strength limitations on clinical MRI scanners, pulsed gradient spin echo (PGSE) measurements are impractical for probing the S/V limit. To achieve this limit on clinical systems, an oscillating gradient spin echo (OGSE) sequence was developed...
May 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28323377/accuracy-of-pdff-estimation-by-magnitude-based-and-complex-based-mri-in-children-with-mr-spectroscopy-as-a-reference
#12
William M Haufe, Tanya Wolfson, Catherine A Hooker, Jonathan C Hooker, Yesenia Covarrubias, Alex N Schlein, Gavin Hamilton, Michael S Middleton, Jorge E Angeles, Diego Hernando, Scott B Reeder, Jeffrey B Schwimmer, Claude B Sirlin
PURPOSE: To assess and compare the accuracy of magnitude-based magnetic resonance imaging (MRI-M) and complex-based MRI (MRI-C) for estimating hepatic proton density fat fraction (PDFF) in children, using MR spectroscopy (MRS) as the reference standard. A secondary aim was to assess the agreement between MRI-M and MRI-C. MATERIALS AND METHODS: This was a HIPAA-compliant, retrospective analysis of data collected in children enrolled in prospective, Institutional Review Board (IRB)-approved studies between 2012 and 2014...
March 21, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28318741/neonatal-magnetic-resonance-imaging-without-sedation-correlates-with-injury-severity-in-brachial-plexus-birth-palsy
#13
Andrea S Bauer, Peter Y Shen, Anna E Nidecker, Paul S Lee, Michelle A James
PURPOSE: Which infants with brachial plexus birth palsy (BPBP) should undergo microsurgical plexus reconstruction remains controversial. The current gold standard for the decision for plexus reconstruction is serial clinical examinations, but this approach obviates the possibility of early surgical treatment. We hypothesize that a new technique using 3-dimensional volumetric proton density magnetic resonance imaging (MRI) without sedation can evaluate the severity of BPBP injury earlier than serial clinical examinations...
March 16, 2017: Journal of Hand Surgery
https://www.readbyqxmd.com/read/28306556/metal-artifact-reduction-in-mri-based-cervical-cancer-intracavitary-brachytherapy
#14
Yuan James Rao, Jacqueline E Zoberi, Mo Kadbi, Perry W Grigsby, Jochen Cammin, Stacie L Mackey, Jose Garcia-Ramirez, S Murty Goddu, Julie K Schwarz, H Michael Gach
Magnetic resonance imaging (MRI) plays an increasingly important role in brachytherapy planning for cervical cancer. Yet, metal tandem, ovoid intracavitary applicators, and fiducial markers used in brachytherapy cause magnetic susceptibility artifacts in standard MRI. These artifacts may impact the accuracy of brachytherapy treatment and the evaluation of tumor response by misrepresenting the size and location of the metal implant, and distorting the surrounding anatomy and tissue. Metal artifact reduction sequences (MARS) with high bandwidth RF selective excitations and turbo spin-echo readouts were developed for MRI of orthopedic implants...
April 21, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28296979/feasibility-of-assessing-bone-matrix-and-mineral-properties-in-vivo-by-combined-solid-state-1h-and-31p-mri
#15
Xia Zhao, Hee Kwon Song, Alan C Seifert, Cheng Li, Felix W Wehrli
PURPOSE: To develop and evaluate an integrated imaging protocol for bone water and phosphorus quantification in vivo by solid-state 1H and 31P MRI. MATERIALS AND METHODS: All studies were HIPAA-compliant and were performed with institutional review board approval and written informed consent. Proton (1H) ultra-short echo-time (UTE) and phosphorus (31P) zero echo-time (ZTE) sequences were designed and implemented on a 3 T clinical MR scanner to quantify bone water and mineral in vivo...
2017: PloS One
https://www.readbyqxmd.com/read/28282807/radiological-pathological-correlation-in-alzheimer-s-disease-systematic-review-of-antemortem-magnetic-resonance-imaging-findings
#16
Caroline Dallaire-Théroux, Brandy L Callahan, Olivier Potvin, Stéphan Saikali, Simon Duchesne
BACKGROUND: The standard method of ascertaining Alzheimer's disease (AD) remains postmortem assessment of amyloid plaques and neurofibrillary degeneration. Vascular pathology, Lewy bodies, TDP-43, and hippocampal sclerosis are frequent comorbidities. There is therefore a need for biomarkers that can assess these etiologies and provide a diagnosis in vivo. OBJECTIVE: We conducted a systematic review of published radiological-pathological correlation studies to determine the relationship between antemortem magnetic resonance imaging (MRI) and neuropathological findings in AD...
2017: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/28280105/measurement-of-the-distribution-of-ventilation-perfusion-ratios-in-the-human-lung-with-proton-mri-comparison-with-the-multiple-inert-gas-elimination-technique
#17
Rui Carlos Sá, Angela Cortney Henderson, Tatum S Simonson, Tatsuya J Arai, Harrieth Wagner, Rebecca J Theilmann, Peter D Wagner, Gordon Kim Prisk, Susan Roberta Hopkins
We have developed a novel functional proton magnetic resonance imaging (MRI) technique to measure regional ventilation-perfusion (VA/Q ) ratio in the lung. We conducted a comparison study of this technique in healthy subjects (n=7, age=42±16, Forced expiratory volume in 1 second=94% predicted), by comparing data measured using MRI to that obtained from the multiple inert gas elimination technique (MIGET). Regional ventilation measured in a sagittal lung slice using Specific Ventilation Imaging was combined with proton density measured using a fast gradient-echo sequence to calculate regional alveolar ventilation, registered with perfusion images acquired using arterial spin labeling, and divided on a voxel-by-voxel basis to obtain regional VA/Q ratio...
March 9, 2017: Journal of Applied Physiology
https://www.readbyqxmd.com/read/28267360/a-pilot-comparative-study-of-quantitative-ultrasound-conventional-ultrasound-and-mri-for-predicting-histology-determined-steatosis-grade-in-adult-nonalcoholic-fatty-liver-disease
#18
Jeremy S Paige, Gregory S Bernstein, Elhamy Heba, Eduardo A C Costa, Marilia Fereirra, Tanya Wolfson, Anthony C Gamst, Mark A Valasek, Grace Y Lin, Aiguo Han, John W Erdman, William D O'Brien, Michael P Andre, Rohit Loomba, Claude B Sirlin
OBJECTIVE: The purpose of this study is to explore the diagnostic performance of two investigational quantitative ultrasound (QUS) parameters, attenuation coefficient and backscatter coefficient, in comparison with conventional ultrasound (CUS) and MRI-estimated proton density fat fraction (PDFF) for predicting histology-confirmed steatosis grade in adults with nonalcoholic fatty liver disease (NAFLD). SUBJECTS AND METHODS: In this prospectively designed pilot study, 61 adults with histology-confirmed NAFLD were enrolled from September 2012 to February 2014...
May 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/28257339/symri-of-the-brain-rapid-quantification-of-relaxation-rates-and-proton-density-with-synthetic-mri-automatic-brain-segmentation-and-myelin-measurement
#19
Akifumi Hagiwara, Marcel Warntjes, Masaaki Hori, Christina Andica, Misaki Nakazawa, Kanako Kunishima Kumamaru, Osamu Abe, Shigeki Aoki
Conventional magnetic resonance images are usually evaluated using the image signal contrast between tissues and not based on their absolute signal intensities. Quantification of tissue parameters, such as relaxation rates and proton density, would provide an absolute scale; however, these methods have mainly been performed in a research setting. The development of rapid quantification, with scan times in the order of 6 minutes for full head coverage, has provided the prerequisites for clinical use. The aim of this review article was to introduce a specific quantification method and synthesis of contrast-weighted images based on the acquired absolute values, and to present automatic segmentation of brain tissues and measurement of myelin based on the quantitative values, along with application of these techniques to various brain diseases...
March 3, 2017: Investigative Radiology
https://www.readbyqxmd.com/read/28241076/characterisation-of-liver-fat-in-the-uk-biobank-cohort
#20
Henry R Wilman, Matt Kelly, Steve Garratt, Paul M Matthews, Matteo Milanesi, Amy Herlihy, Micheal Gyngell, Stefan Neubauer, Jimmy D Bell, Rajarshi Banerjee, E Louise Thomas
Non-alcoholic fatty liver disease and the risk of progression to steatohepatitis, cirrhosis and hepatocellular carcinoma have been identified as major public health concerns. We have demonstrated the feasibility and potential value of measuring liver fat content by magnetic resonance imaging (MRI) in a large population in this study of 4,949 participants (aged 45-73 years) in the UK Biobank imaging enhancement. Despite requirements for only a single (≤3min) scan of each subject, liver fat was able to be measured as the MRI proton density fat fraction (PDFF) with an overall success rate of 96...
2017: PloS One
keyword
keyword
101220
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"