Simulations of high permittivity materials for 7 T neuroimaging and evaluation of a new barium titanate-based dielectric.

abstract：:A new methodology is introduced that characterizes the intravoxel orientation distribution function (ODF) based on a single-fiber model of the diffusion MRI signal. Using a Bayesian framework the probability of finding a fiber in a specific orientation is obtained. The proposed ODF estimation relies on a cigar-like di...

journal_title：Magnetic resonance in medicine

authors： Canales-Rodríguez EJ,Melie-García L,Iturria-Medina Y,Martínez-Montes E,Alemán-Gómez Y,Lin CP

更新日期：2008-09-01 00:00:00

abstract：PURPOSE:To propose and evaluate a deep learning model for rapid and accurate calculation of myocardial T1 /T2 values based on a previously proposed Bloch equation simulation with slice profile correction (BLESSPC) method. METHODS:Deep learning Bloch equation simulations (DeepBLESS) models are proposed for rapid and ac...

journal_title：Magnetic resonance in medicine

authors： Shao J,Ghodrati V,Nguyen KL,Hu P

更新日期：2020-11-01 00:00:00

abstract：:The reconstruction of non-Cartesian k-space trajectories often requires the estimation of nonuniform sampling density. Particularly for 3D, this calculation can be computationally expensive. The method proposed in this work combines an iterative algorithm previously proposed by Pipe and Menon (Magn Reson Med 1999;41:1...

journal_title：Magnetic resonance in medicine

authors： Zwart NR,Johnson KO,Pipe JG

更新日期：2012-03-01 00:00:00

abstract：PURPOSE:To measure the apparent diffusion coefficients (ADC) of five main metabolites in the human brain at 3T with PRESS and STEAM, avoiding measurement biases because of cross-terms. Cross-terms arise from interactions between slice-selection and spoiler gradients in the localized spectroscopy sequence and the diffus...

journal_title：Magnetic resonance in medicine

authors： Deelchand DK,Auerbach EJ,Marjańska M

更新日期：2018-06-01 00:00:00

abstract：:A new fully automatic algorithm for the segmentation of the brain and total intracranial cerebrospinal fluid (CSF) from T(1)-weighted volume MRI scans of the head, called Exbrain v.2, is described. The algorithm was developed in the context of serial intracranial volumetry. A brain mask obtained using a previous versi...

journal_title：Magnetic resonance in medicine

authors： Lemieux L,Hammers A,Mackinnon T,Liu RS

更新日期：2003-05-01 00:00:00

abstract：:The feasibility of reconstructing three-dimensional (3D) MRI data sets from limited-view projections is investigated in phantom and in vivo animal studies to improve the temporal resolution of magnetic resonance angiography without sacrificing spatial resolution. Thirty-two pairs of orthogonal biplane projections are ...

journal_title：Magnetic resonance in medicine

authors： Huang Y,Gurr D,Wright GA

更新日期：2006-01-01 00:00:00

abstract：:Proton-electron double-resonance imaging (PEDRI) was used to assess renal function by monitoring the flow of the exogenous nitroxide free radical proxyl carboxylic acid (PCA) through normal and injured kidneys in the living rat. Kidney damage was induced by treatment with 2-bromoethylamine (BEA), which provides a well...

journal_title：Magnetic resonance in medicine

authors： Seimenis I,Foster MA,Lurie DJ,Hutchison JM,Whiting PH,Payne S

更新日期：1998-08-01 00:00:00

abstract：:Optimal control theory has been applied in the past for the design of RF pulses for selective excitation. This was the outcome of having established the controllability of the MR spin system for the selective excitation problem. "Minimum distance" was the main formulation used for the solution. Because of their robust...

journal_title：Magnetic resonance in medicine

authors： Rosenfeld D,Zur Y

更新日期：1996-09-01 00:00:00

abstract：:The purpose of this study was to demonstrate the feasibility of dynamic oxygen-enhanced MRI in a clinical setting. We hypothesized that dynamic oxygen enhancement can reflect the regional diffusing capacity of the lung. Ten patients with pulmonary emphysema and seven healthy volunteers were examined with a respiratory...

journal_title：Magnetic resonance in medicine

authors： Ohno Y,Hatabu H,Takenaka D,Van Cauteren M,Fujii M,Sugimura K

更新日期：2002-06-01 00:00:00

abstract：PURPOSE:Subendocardial dark-rim artifacts (DRAs) remain a major concern in first-pass perfusion (FPP) myocardial MRI and may lower the diagnostic accuracy for detection of ischemia. A major source of DRAs is the "Gibbs ringing" effect. We propose an optimized radial acquisition strategy aimed at eliminating ringing-ind...

journal_title：Magnetic resonance in medicine

authors： Sharif B,Dharmakumar R,LaBounty T,Arsanjani R,Shufelt C,Thomson L,Merz CN,Berman DS,Li D

更新日期：2014-07-01 00:00:00

abstract：:Phase-contrast magnetic resonance imaging is subject to numerous sources of error, which decrease clinical confidence in the reported measures. This work outlines how stationary perivascular fat can impart a significant chemical shift induced phase-contrast magnetic resonance imaging measurement error using computatio...

journal_title：Magnetic resonance in medicine

authors： Middione MJ,Ennis DB

更新日期：2013-02-01 00:00:00

abstract：:In this work, a new double quantum filter for glutathione (GSH) editing is introduced, combined with the point-resolved spectroscopy localization sequence (PRESS), and demonstrated in vivo. Compared to the conventional double quantum coherence filter, the new filter has two major advantages. First, it eliminates the n...

journal_title：Magnetic resonance in medicine

authors： Zhao T,Heberlein K,Jonas C,Jones DP,Hu X

更新日期：2006-03-01 00:00:00

abstract：PURPOSE:MR safety at 7 Tesla relies on accurate numerical simulations of transmit electromagnetic fields to fully assess local specific absorption rate (SAR) safety. Numerical simulations for SAR safety are currently performed using models of healthy patients. These simulations might not be useful for estimating SAR in...

journal_title：Magnetic resonance in medicine

authors： Restivo MC,van den Berg CA,van Lier AL,Polders DL,Raaijmakers AJ,Luijten PR,Hoogduin H

更新日期：2016-01-01 00:00:00

abstract：:A new parallel imaging technique was implemented which can result in reduced image acquisition times in MRI. MR data is acquired in parallel using an array of receiver coils and then reconstructed simultaneously with multiple processors. The method requires the initial estimation of the 2D sensitivity profile of each ...

journal_title：Magnetic resonance in medicine

authors： Kyriakos WE,Panych LP,Kacher DF,Westin CF,Bao SM,Mulkern RV,Jolesz FA

更新日期：2000-08-01 00:00:00

abstract：PURPOSE:To investigate whether saturation using existing methods developed for 3T imaging is feasible for clinical perfusion imaging at 7T, and to propose a new design of saturation pulse train for first-pass myocardial perfusion imaging at 7T. METHODS:The new design of saturation pulse train consists of four hyperbol...

journal_title：Magnetic resonance in medicine

authors： Tao Y,Hess AT,Keith GA,Rodgers CT,Liu A,Francis JM,Neubauer S,Robson MD

更新日期：2015-04-01 00:00:00

abstract：:Minimally invasive cardiac surgery requires arresting and emptying of the heart, which compromises visualization of the surgical field. In this feasibility study a novel surgical procedure is demonstrated in which real-time MRI is used to guide the placement of a prosthetic aortic valve in the beating heart via direct...

journal_title：Magnetic resonance in medicine

authors： McVeigh ER,Guttman MA,Lederman RJ,Li M,Kocaturk O,Hunt T,Kozlov S,Horvath KA

更新日期：2006-11-01 00:00:00

abstract：PURPOSE:To obviate online slice-by-slice RF shim optimization and reduce B1+ mapping requirements for patient-specific RF shimming in high-field magnetic resonance imaging. THEORY AND METHODS:RF Shim Prediction by Iteratively Projected Ridge Regression (PIPRR) predicts patient-specific, SAR-efficient RF shims with a m...

journal_title：Magnetic resonance in medicine

authors： Ianni JD,Cao Z,Grissom WA

更新日期：2018-11-01 00:00:00

abstract：:The signals of water in the different compartments of rat sciatic nerve are resolved in the (2)H double-quantum-filtered NMR spectrum, due to their different quadrupolar splittings and relaxation rates. This resolution allowed the independent measurement of the water diffusion coefficients in the different compartment...

journal_title：Magnetic resonance in medicine

authors： Seo Y,Shinar H,Morita Y,Navon G

更新日期：1999-09-01 00:00:00

abstract：PURPOSE:Intracranial and intraspinal compliance are parameters of interest in the diagnosis and prediction of treatment outcome in patients with normal pressure hydrocephalus and other forms of communicating hydrocephalus. A noninvasive method to estimate the spinal cerebrospinal fluid (CSF) pulse wave velocity (PWV) a...

journal_title：Magnetic resonance in medicine

authors： Sonnabend K,Brinker G,Maintz D,Bunck AC,Weiss K

更新日期：2021-01-01 00:00:00

abstract：PURPOSE:Simultaneous brain and spinal cord functional MRI is emerging as a new tool to study the central nervous system but is challenging. Poor B0 homogeneity and small size of the spinal cord are principal obstacles to this nascent technology. Here we extend a dynamic shimming approach, first posed by Finsterbusch, b...

journal_title：Magnetic resonance in medicine

authors： Islam H,Law CSW,Weber KA,Mackey SC,Glover GH

更新日期：2019-02-01 00:00:00

abstract：:The accuracy of the outcome in a diffusion tensor imaging (DTI) experiment depends on the acquisition scheme as well as the postprocessing methods used. In the present study, the DTI results acquired after applying different combinations of diffusion-weighted (DW) gradient orientations were initially compared. Then, s...

journal_title：Magnetic resonance in medicine

authors： Arfanakis K,Cordes D,Haughton VM,Carew JD,Meyerand ME

更新日期：2002-02-01 00:00:00

abstract：:A stimulated echo sequence was used to obtain 19F NMR spectra from within a 4-ml voxel in a cat brain. The time dependence of the 19F NMR signal from an inert gas (CHF3) was used to calculate the blood flow in the voxel. The position of the voxel was selected using a 1H MR image. ...

journal_title：Magnetic resonance in medicine

authors： van Zijl PC,Ligeti L,Sinnwell T,Alger JR,Chesnick AS,Moonen CT,McLaughlin AC

更新日期：1990-12-01 00:00:00

abstract：PURPOSE:To evaluate the feasibility of an improved motion and flow robust methodology for imaging the pulmonary vasculature using non-contrast-enhanced, free-breathing, golden-angle radial MRI. METHODS:Healthy volunteers (n = 10, age 46 ± 11 years, 50% female) and patients (n = 2, ages 27 and 84, both female) were ima...

journal_title：Magnetic resonance in medicine

authors： Fyrdahl A,Vargas Paris R,Nyrén S,Holst K,Ugander M,Lindholm P,Sigfridsson A

更新日期：2018-11-01 00:00:00

abstract：PURPOSE:The goal of this study was to conduct an exposure assessment for workers moving through the stray stationary field of common MRI scanners, performed according to the recent International Commission on Non-Ionizing Radiation Protection (ICNIRP) Guidelines, which aim at avoiding annoying sensory effects. THEORY ...

journal_title：Magnetic resonance in medicine

authors： Zilberti L,Bottauscio O,Chiampi M

更新日期：2016-10-01 00:00:00

abstract：:A multimodal MR study including relaxometry, diffusion tensor imaging (DTI), and MR spectroscopy was performed on patients with classical phenylketonuria (PKU) and matched controls, to improve our understanding of white matter (WM) lesions. Relaxometry yields information on myelin loss or malformation and may substant...

journal_title：Magnetic resonance in medicine

authors： Vermathen P,Robert-Tissot L,Pietz J,Lutz T,Boesch C,Kreis R

更新日期：2007-12-01 00:00:00

abstract：PURPOSE:To investigate the effect of realistic microstructural geometry on the susceptibility-weighted MR signal in white matter (WM), with application to demyelination. METHODS:Previous work has modeled susceptibility-weighted signals under the assumption that axons are cylindrical. In this study, we explored the imp...

journal_title：Magnetic resonance in medicine

authors： Xu T,Foxley S,Kleinnijenhuis M,Chen WC,Miller KL

更新日期：2018-01-01 00:00:00

abstract：:Continuously moving table (CMT) MRI is a new method that is capable of generating 3D, seamless, large field-of-view (FOV) images by acquiring readouts along the patient superior-inferior axis as the subject is translated through the scanner. For applications that require artifact-free images, such as arterial-phase co...

journal_title：Magnetic resonance in medicine

authors： Sabati M,Lauzon ML,Mahallati H,Frayne R

更新日期：2006-05-01 00:00:00

abstract：:MR imaging experiments were conducted to investigate the feasibility of estimating vascular pulse pressure waveforms from measurements of blood flow rates and vessel cross-sectional area. Blood flow waveforms were measured in the aorta's of three 25-30-kg pigs at multiple imaging sections using phase-contrast velocity...

journal_title：Magnetic resonance in medicine

authors： Urchuk SN,Fremes SE,Plewes DB

更新日期：1997-08-01 00:00:00

abstract：:A method is demonstrated for detection of magnetization from a selected region within the sensitive volume of a surface coil in a single acquisition. Composite pulses are described which eliminate signals from regions where magnetization is rotated 270 and 450 degrees. There is a loss of 1.3% or less of signal from re...

journal_title：Magnetic resonance in medicine

authors： Karczmar GS,Matson GB,Weiner MW

更新日期：1986-04-01 00:00:00

abstract：:Multiple-slice perfusion imaging by continuous arterial spin labeling (CASL) is made possible by amplitude modulation (AM) of the labeling RF pulse, but perfusion sensitivity is reduced relative to the single-slice technique. A computer model of the Bloch equations for velocity driven adiabatic fast passage was develo...

journal_title：Magnetic resonance in medicine

authors： Utting JF,Thomas DL,Gadian DG,Helliar RW,Lythgoe MF,Ordidge RJ

更新日期：2005-09-01 00:00:00