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https://www.readbyqxmd.com/read/28342212/high-speed-whole-brain-oximetry-by-golden-angle-radial-mri
#1
Wen Cao, Yulin V Chang, Erin K Englund, Hee Kwon Song, Suliman Barhoum, Zachary B Rodgers, Michael C Langham, Felix W Wehrli
PURPOSE: To determine whole-brain cerebral metabolic rate of oxygen (CMRO2 ), an improved imaging approach, based on radial encoding, termed radial OxFlow (rOxFlow), was developed to simultaneously quantify draining vein venous oxygen saturation (SvO2 ) and total cerebral blood flow (tCBF). METHODS: To evaluate the efficiency and precision of the rOxFlow sequence, 10 subjects were studied during a paradigm of repeated breath-holds with both rOxFlow and Cartesian OxFlow (cOxFlow) sequences...
March 25, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28342191/exploiting-multicompartment-effects-in-triple-echo-steady-state-t2-mapping-for-fat-fraction-quantification
#2
Dian Liu, Andreas Steingoetter, Jelena Curcic, Sebastian Kozerke
PURPOSE: To investigate and exploit the effect of intravoxel off-resonance compartments in the triple-echo steady-state (TESS) sequence without fat suppression for T2 mapping and to leverage the results for fat fraction quantification. METHODS: In multicompartment tissue, where at least one compartment is excited off-resonance, the total signal exhibits periodic modulations as a function of echo time (TE). Simulated multicompartment TESS signals were synthesized at various TEs...
March 25, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28342176/investigating-the-physiological-effects-of-10-5-tesla-static-field-exposure-on-anesthetized-swine
#3
Yigitcan Eryaman, Patrick Zhang, Lynn Utecht, Kivanc Kose, Russell L Lagore, Lance DelaBarre, Jeramy Kulesa, Lynn E Eberly, Gregor Adriany, Tinen L Iles, Paul A Iaizzo, J Thomas Vaughan, Kamil Ugurbil
PURPOSE: In this work, we investigated the relative effects of static magnetic field exposure (10.5 Tesla [T]) on two physiological parameters; blood pressure (BP) and heart rate (HR). METHODS: In vivo, we recorded both BP and HR in 4 swine (3 female, 1 male) while they were positioned within a 10.5T magnet. All measurements were performed invasively within these anesthetized animals by the placement of pressure catheters into their carotid arteries. RESULTS: We measured average increases of 2...
March 25, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28341581/the-graham-jackson-memorial-lecture-issm-2016-the-man-who-knew-too-much-time-to-recognize-erectile-dysfunction-and-low-testosterone-as-independent-risk-factors-for-cardiovascular-disease
#4
REVIEW
Geoffrey Hackett
INTRODUCTION: Graham Jackson introduced the concept that erectile dysfunction (ED) is a marker for undiagnosed cardiovascular (CV) disease and future events. In the Princeton 3 guidelines, he recognized the important impact of testosterone deficiency (TD) on all-cause and CV mortality. Recent evidence suggests that testosterone therapy to target levels and for sufficient duration decreases CV events. Unfortunately, this had a modest impact on CV disease management because ED is not incorporated into current risk calculators...
March 21, 2017: Sexual Medicine Reviews
https://www.readbyqxmd.com/read/28341580/efficacy-and-safety-of-sildenafil-in-men-with-sexual-dysfunction-and-spinal-cord-injury
#5
REVIEW
Dana A Ohl, Martin Carlsson, Vera J Stecher, Gregory A Rippon
INTRODUCTION: Spinal cord injury (SCI) is estimated to affect approximately 276,000 individuals in the United States. Since 2010, the mean age of individuals at the time of the SCI has been 42 years, with nearly 80% of cases involving men. This means that individuals with SCI generally are young men who typically place a great deal of importance on normal sexual and reproductive function. AIM: To assess the effect of sildenafil treatment on erectile function and the frequency of ejaculation in men with SCI...
March 21, 2017: Sexual Medicine Reviews
https://www.readbyqxmd.com/read/28337782/three-dimensional-oxygen-enhanced-mri-of-the-human-lung-at-1-5t-with-ultra-fast-balanced-steady-state-free-precession
#6
Orso Pusterla, Grzegorz Bauman, Oliver Bieri
PURPOSE: To assess the feasibility of 3D oxygen-enhanced (OE) MRI of the lung at 1.5T using multi-volumetric ultra-fast balanced steady-state free precession (ufSSFP) acquisitions. METHODS: Isotropic imaging of the lung for OE-MRI was performed with an adapted 3D ufSSFP sequence using five breath-hold acquisitions ranging from functional residual capacity to tidal inspiration under both normoxic (room air) and hyperoxic (100% O2 ) gas conditions. For each O2 concentration, a sponge model (which captures the parenchymal signal intensity variation as a function of the lung volume) was fitted to the acquired multi-volumetric datasets after semiautomatic lung segmentation and deformable image registration...
March 24, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28321915/acceleration-of-asl-based-time-resolved-mr-angiography-by-acquisition-of-control-and-labeled-images-in-the-same-shot-actress
#7
Yuriko Suzuki, Noriyuki Fujima, Tetsuo Ogino, James Alastair Meakin, Akira Suwa, Hiroyuki Sugimori, Marc Van Cauteren, Matthias J P van Osch
PURPOSE: Noncontrast 4D-MR-angiography (MRA) using arterial spin labeling (ASL) is beneficial because high spatial and temporal resolution can be achieved. However, ASL requires acquisition of labeled and control images for each phase. The purpose of this study is to present a new accelerated 4D-MRA approach that requires only a single control acquisition, achieving similar image quality in approximately half the scan time. METHODS: In a multi-phase Look-Locker sequence, the first phase was used as the control image and the labeling pulse was applied before the second phase...
March 20, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28321914/a-compact-0-5%C3%A2-t-mr-elastography-device-and-its-application-for-studying-viscoelasticity-changes-in-biological-tissues-during-progressive-formalin-fixation
#8
Jürgen Braun, Heiko Tzschätzsch, Clara Körting, Angela Ariza de Schellenberger, Marika Jenderka, Toni Drießle, Michael Ledwig, Ingolf Sack
PURPOSE: To develop a method of compact tabletop magnetic resonance elastography (MRE) for rheological tests of tissue samples and to measure changes in viscoelastic powerlaw constants of liver and brain tissue during progressive fixation. METHODS: A 10-mm bore, 0.5-T permanent-magnet-based MRI system was equipped with a gradient-amplifier-controlled piezo-actuator and motion-sensitive spin echo sequence for inducing and measuring harmonic shear vibrations in cylindrical samples...
March 20, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28321908/reduced-field-of-view-single-shot-spiral-perfusion-imaging
#9
Yang Yang, Li Zhao, Xiao Chen, Peter W Shaw, Jorge A Gonzalez, Frederick H Epstein, Craig H Meyer, Christopher M Kramer, Michael Salerno
PURPOSE: To develop a single-shot spiral perfusion pulse sequence with outer-volume suppression (OVS) to achieve whole-heart coverage with a short temporal footprint of 10 ms per slice location. METHODS: A highly accelerated single-shot variable density spiral pulse sequence with an integrated OVS module for reduced field of view (rFOV) perfusion imaging with 2 mm spatial resolution was developed and evaluated in simulations, phantom experiments and in clinical patients with (n = 8) or without (n = 8) OVS...
March 20, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28321904/rotating-single-shot-acquisition-rosa-with-composite-reconstruction-for-fast-high-resolution-diffusion-imaging
#10
Qiuting Wen, Chandana Kodiweera, Brian M Dale, Giri Shivraman, Yu-Chien Wu
PURPOSE: To accelerate high-resolution diffusion imaging, rotating single-shot acquisition (RoSA) with composite reconstruction is proposed. Acceleration was achieved by acquiring only one rotating single-shot blade per diffusion direction, and high-resolution diffusion-weighted (DW) images were reconstructed by using similarities of neighboring DW images. A parallel imaging technique was implemented in RoSA to further improve the image quality and acquisition speed. RoSA performance was evaluated by simulation and human experiments...
March 20, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28321903/spin-lock-imaging-of-exogenous-exchange-based-contrast-agents-to-assess-tissue-ph
#11
Zhongliang Zu, Hua Li, Xiaoyu Jiang, John C Gore
PURPOSE: Some X-ray contrast agents contain exchangeable protons that give rise to exchange-based effects on MRI, including chemical exchange saturation transfer (CEST). However, CEST has poor specificity to explicit exchange parameters. Spin-lock sequences at high field are also sensitive to chemical exchange. Here, we evaluate whether spin-locking techniques can detect the contrast agent iohexol in vivo after intravenous administration, and their potential for measuring changes in tissue pH...
March 20, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28321902/modeling-real-shim-fields-for-very-high-degree-and-order-b0-shimming-of-the-human-brain-at-9-4%C3%A2-t
#12
Paul Chang, Sahar Nassirpour, Anke Henning
PURPOSE: To describe the process of calibrating a B0 shim system using high-degree (or high order) spherical harmonic models of the measured shim fields, to provide a method that considers amplitude dependency of these models, and to show the advantage of very high-degree B0 shimming for whole-brain and single-slice applications at 9.4 Tesla (T). METHODS: An insert shim with up to fourth and partial fifth/sixth degree (order) spherical harmonics was used with a Siemens 9...
March 20, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28321901/a-pneumatic-phantom-for-mimicking-respiration-induced-artifacts-in-spinal-mri
#13
Philippe De Tillieux, Ryan Topfer, Alexandru Foias, Iris Leroux, Imanne El Maâchi, Hugues Leblond, Nikola Stikov, Julien Cohen-Adad
PURPOSE: To design a phantom capable of mimicking human respiration to serve as a testing platform for correction of the static and time-evolving magnetic field distortions typically encountered in MRI of the spinal cord. METHODS: An inflation system to mimic the air variation of the human lungs was constructed. The inflation system was linked to a phantom containing synthetic lungs and an ex vivo human spine. The relationship between air pressure and phantom lung volume was evaluated via imaging experiment...
March 20, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28321900/coronary-mr-angiography-using-image-based-respiratory-motion-compensation-with-inline-correction-and-fixed-gating-efficiency
#14
Markus Henningsson, Jouke Smink, Gerald van Ensbergen, Rene Botnar
PURPOSE: The purpose of this study was to evaluate a new inline motion compensation approach called image-based navigation with Constant Respiratory efficiency UsIng Single End-expiratory threshold (iNAV-CRUISE) for coronary MR angiography (CMRA). METHODS: The CRUISE gating technique was combined with iNAV motion correction and implemented inline for motion-compensated CMRA on a 1.5 Tesla scanner. The approach was compared to conventional diaphragmatic navigator gating (dNAVG) in 10 healthy subjects...
March 20, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28317261/diffusion-relaxation-correlation-spectroscopic-imaging-a-multidimensional-approach-for-probing-microstructure
#15
Daeun Kim, Eamon K Doyle, Jessica L Wisnowski, Joong Hee Kim, Justin P Haldar
PURPOSE: To propose and evaluate a novel multidimensional approach for imaging subvoxel tissue compartments called Diffusion-Relaxation Correlation Spectroscopic Imaging. THEORY AND METHODS: Multiexponential modeling of MR diffusion or relaxation data is commonly used to infer the many different microscopic tissue compartments that contribute signal to macroscopic MR imaging voxels. However, multiexponential estimation is known to be difficult and ill-posed. Observing that this ill-posedness is theoretically reduced in higher dimensions, diffusion-relaxation correlation spectroscopic imaging uses a novel multidimensional imaging experiment that jointly encodes diffusion and relaxation information, and then uses a novel constrained reconstruction technique to generate a multidimensional diffusion-relaxation correlation spectrum for every voxel...
March 19, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28316080/toward-a-very-brief-self-report-to-assess-the-core-symptoms-of-depression-vqids-sr5
#16
N De La Garza, A John Rush, B D Grannemann, M H Trivedi
OBJECTIVE: To develop a short, 5-item measure of the core symptoms of depression based on the 16-item Quick Inventory of Depressive Symptomatology - Self-Report (QIDS-SR16 ) and to evaluate psychometric properties of this new measure (Very Quick Inventory of Depressive Symptomatology - Self-Report: VQIDS-SR5 ). METHOD: Using data from a convenience sample of the Combining Medications to Enhance Depression Outcomes (CO-MED) trial, we evaluated the psychometric properties of the VQIDS-SR5 , its sensitivity to change, and its comparability to the QIDS-SR16 and clinician-rated scales (QIDS-C16 and VQIDS-C5 )...
March 17, 2017: Acta Psychiatrica Scandinavica
https://www.readbyqxmd.com/read/28303617/joint-system-relaxometry-jsr-and-cr%C3%A3-mer-rao-lower-bound-optimization-of-sequence-parameters-a-framework-for-enhanced-precision-of-despot-t1-and-t2-estimation
#17
Rui Pedro A G Teixeira, Shaihan J Malik, Joseph V Hajnal
PURPOSE: This study aims to increase the precision of single-compartment DESPOT relaxometry by two means: (i) a joint system relaxometry (JSR) approach that estimates parameters in a single step using all available data; and (ii) optimizing acquisition parameters by deploying a robust design tool based on the Crámer-Rao lower bound (CRLB). METHODS: Following the development of the analysis and design capabilities, phantom and four in vivo subject experiments were performed to compare directly the precision achieved with DESPOT and JSR estimation using published protocols and protocols designed using a proposed CRLB framework...
March 16, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28303611/improving-left-ventricular-segmentation-in-four-dimensional-flow-mri-using-intramodality-image-registration-for-cardiac-blood-flow-analysis
#18
Vikas Gupta, Mariana Bustamante, Alexandru Fredriksson, Carl-Johan Carlhäll, Tino Ebbers
PURPOSE: Assessment of blood flow in the left ventricle using four-dimensional flow MRI requires accurate left ventricle segmentation that is often hampered by the low contrast between blood and the myocardium. The purpose of this work is to improve left-ventricular segmentation in four-dimensional flow MRI for reliable blood flow analysis. METHOD: The left ventricle segmentations are first obtained using morphological cine-MRI with better in-plane resolution and contrast, and then aligned to four-dimensional flow MRI data...
March 16, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28303591/-31-p-magnetization-transfer-magnetic-resonance-spectroscopy-assessing-the-activation-induced-change-in-cerebral-atp-metabolic-rates-at-3-t
#19
Chen Chen, Mary C Stephenson, Andrew Peters, Peter G Morris, Susan T Francis, Penny A Gowland
PURPOSE: In vivo (31) P magnetic resonance spectroscopy (MRS) magnetization transfer (MT) provides a direct measure of neuronal activity at the metabolic level. This work aims to use functional (31) P MRS-MT to investigate the change in cerebral adenosine triphosphate (ATP) metabolic rates in healthy adults upon repeated visual stimuli. METHODS: A magnetization saturation transfer sequence with narrowband selective saturation of γ-ATP was developed for (31) P MT experiments at 3 T...
March 16, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28301460/clinical-laboratories-collaborate-to-resolve-differences-in-variant-interpretations-submitted-to-clinvar
#20
Steven M Harrison, Jill S Dolinsky, Amy E Knight Johnson, Tina Pesaran, Danielle R Azzariti, Sherri Bale, Elizabeth C Chao, Soma Das, Lisa Vincent, Heidi L Rehm
PURPOSE: Data sharing through ClinVar offers a unique opportunity to identify interpretation differences between laboratories. As part of a ClinGen initiative, four clinical laboratories (Ambry, GeneDx, Partners Healthcare Laboratory for Molecular Medicine, and University of Chicago Genetic Services Laboratory) collaborated to identify the basis of interpretation differences and to investigate if data sharing and reassessment resolve interpretation differences by analyzing a subset of variants...
March 16, 2017: Genetics in Medicine: Official Journal of the American College of Medical Genetics
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