In vivo measurement of volumetric strain in the human brain induced by arterial pulsation and harmonic waves.

abstract：PURPOSE:For ultrahigh field (UHF) MRI, the expected local specific absorption rate (SAR) distribution is usually calculated by numerical simulations using a limited number of generic body models and adding a safety margin to take into account intersubject variability. Assessment of this variability with a large model d...

journal_title：Magnetic resonance in medicine

authors： Meliadò EF,van den Berg CAT,Luijten PR,Raaijmakers AJE

更新日期：2019-03-01 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：:Magnetic resonance (MR) imaging and relaxation time measurements of bioresorbable implants made of polylactic acid (PLA), as well as the surrounding tissues, were carried out over a period of 6 months to monitor the implant state and the body's responses, and to determine how these processes are reflected in MR data. ...

journal_title：Magnetic resonance in medicine

authors： Stroman PW,Dorvil JC,Marois Y,Poddevin N,Guidoin R

更新日期：1999-07-01 00:00:00

abstract：PURPOSE:To present and validate a new method that formalizes a direct link between k-space and wavelet domains to apply separate undersampling and reconstruction for high- and low-spatial-frequency k-space data. THEORY AND METHODS:High- and low-spatial-frequency regions are defined in k-space based on the separation o...

journal_title：Magnetic resonance in medicine

authors： Sung K,Hargreaves BA

更新日期：2013-11-01 00:00:00

abstract：:This work aimed to investigate the effects of administering Gd-DTPA on the BOLD effect, and to determine the feasibility of using this approach to measure fractional changes in blood volume and blood oxygenation on neuronal activation during a visual paradigm. A linear relationship between cortical R(2)(*) and the int...

journal_title：Magnetic resonance in medicine

authors： Pears JA,Francis ST,Butterworth SE,Bowtell RW,Gowland PA

更新日期：2003-01-01 00:00:00

abstract：:A pulse sequence is presented for obtaining a single image with combined T1/T2 weighting. T2 relaxation is made to increase intensity, in cooperation with the effect of T1 relaxation, by providing T2 weighting with a 90 degrees-180 degrees-90 degrees driven inversion pulse triplet in an inversion recovery method. Unli...

journal_title：Magnetic resonance in medicine

authors： Conturo TE,Kessler RM,Beth AH

更新日期：1990-09-01 00:00:00

abstract：PURPOSE:Oscillating gradient spin-echo (OGSE) diffusion MRI provides information about the microstructure of biological tissues by means of the frequency dependence of the apparent diffusion coefficient (ADC). ADC dependence on OGSE frequency has been explored in numerous rodent studies, but applications in the human b...

journal_title：Magnetic resonance in medicine

authors： Arbabi A,Kai J,Khan AR,Baron CA

更新日期：2020-06-01 00:00:00

abstract：PURPOSE:To propose a phase error correction scheme for monopolar time-interleaved multi-echo gradient echo water-fat imaging that allows accurate and robust complex-based quantification of the proton density fat fraction (PDFF). METHODS:A three-step phase correction scheme is proposed to address a) a phase term induce...

journal_title：Magnetic resonance in medicine

authors： Ruschke S,Eggers H,Kooijman H,Diefenbach MN,Baum T,Haase A,Rummeny EJ,Hu HH,Karampinos DC

更新日期：2017-09-01 00:00:00

abstract：PURPOSE:Myocardial effective relaxation time T2* is commonly regarded as a surrogate for myocardial tissue oxygenation. However, it is legitimate to assume that there are multiple factors that influence T2*. To this end, this study investigates the relationship between T2* and cardiac macromorphology given by left vent...

journal_title：Magnetic resonance in medicine

authors： Huelnhagen T,Hezel F,Serradas Duarte T,Pohlmann A,Oezerdem C,Flemming B,Seeliger E,Prothmann M,Schulz-Menger J,Niendorf T

更新日期：2017-06-01 00:00:00

abstract：:T2-weighted MRI of edema in acute myocardial infarction (MI) provides a means of differentiating acute and chronic MI, and assessing the area at risk of infarction. Conventional T2-weighted imaging of edema uses a turbo spin-echo (TSE) readout with dark-blood preparation. Clinical applications of dark-blood TSE method...

journal_title：Magnetic resonance in medicine

authors： Kellman P,Aletras AH,Mancini C,McVeigh ER,Arai AE

更新日期：2007-05-01 00:00:00

abstract：:The purpose of this study was to evaluate an optimized multislice acquisition technique for oxygen-enhanced MRI of the lung using slice-selective inversion and refocusing pulses in combination with parallel imaging. An inversion recovery HASTE sequence was implemented with respiratory triggering to perform imaging in ...

journal_title：Magnetic resonance in medicine

authors： Dietrich O,Losert C,Attenberger U,Fasol U,Peller M,Nikolaou K,Reiser MF,Schoenberg SO

更新日期：2005-06-01 00:00:00

abstract：:Proton MR spectroscopy ((1)H-MRS) has been used for in vivo quantification of intracellular triglycerides within the sarcolemma. The purpose of this study was to assess whether breath-hold dual-echo in- and out-of-phase MRI at 3.0 T can quantify the fat content of the myocardium. Biases, including T(1), T*(2), and noi...

journal_title：Magnetic resonance in medicine

authors： Liu CY,Redheuil A,Ouwerkerk R,Lima JA,Bluemke DA

更新日期：2010-04-01 00:00:00

abstract：:Diffusion tensor imaging enables in vivo investigation of tissue cytoarchitecture through parameter contrasts sensitive to water diffusion barriers at the micrometer level. Parameters are derived through an estimation process that is susceptible to noise and artifacts. Estimated parameters (e.g., fractional anisotropy...

journal_title：Magnetic resonance in medicine

authors： Lauzon CB,Crainiceanu C,Caffo BC,Landman BA

更新日期：2013-03-01 00:00:00

abstract：:This study presents the detection of [2-(13)C]glucose metabolism in the carboxylic/amide region in the human brain, and demonstrates that the cerebral metabolism of [2-(13)C]glucose can be studied in human subjects in the presence of severe hardware constraints of widely available 3 T clinical scanners and with low-po...

journal_title：Magnetic resonance in medicine

authors： Li S,Zhang Y,Wang S,Yang J,Ferraris Araneta M,Farris A,Johnson C,Fox S,Innis R,Shen J

更新日期：2009-09-01 00:00:00

abstract：:The study of brain function using MRI relies on acquisition techniques that are sensitive to different aspects of the hemodynamic response contiguous to areas of neuronal activity. For this purpose different contrasts such as arterial spin labeling (ASL) and blood oxygenation level dependent (BOLD) functional MRI tech...

journal_title：Magnetic resonance in medicine

authors： Woolrich MW,Chiarelli P,Gallichan D,Perthen J,Liu TT

更新日期：2006-10-01 00:00:00

abstract：:Quantitative MRI assessment of leukoencephalopathy is difficult because the MRI properties of leukoencephalopathy significantly overlap those of normal tissue. This report describes the use of an automated procedure for longitudinal measurement of tissue volume and relaxation times to quantify leukoencephalopathy. Ima...

journal_title：Magnetic resonance in medicine

authors： Reddick WE,Glass JO,Langston JW,Helton KJ

更新日期：2002-05-01 00:00:00

abstract：PURPOSE:This study aims to identify work-related and personal factors associated with workers' exposure to static magnetic fields (SMF) and motion-induced time-varying magnetic fields (TVMF) from MRI scanners. METHODS:Measurements of personal exposure to SMF and TVMF were performed among MRI staff during 439 work shif...

journal_title：Magnetic resonance in medicine

authors： Schaap K,Christopher-De Vries Y,Cambron-Goulet É,Kromhout H

更新日期：2016-05-01 00:00:00

abstract：PURPOSE:To develop and evaluate a method for RF envelope correction without extra hardware or synchronization. METHODS:Transmitted RF waveforms are measured through a simple pulse sequence called the gradient reversal approach to evaluate RF (GRATER). The measured RF waveforms are used to compute predistorted RF wavef...

journal_title：Magnetic resonance in medicine

authors： Landes VL,Nayak KS

更新日期：2020-01-01 00:00:00

abstract：:Strong, extensive magnetic fringe fields are a significant problem with magnetic resonance imaging magnets. This is particularly acute with 4-T, whole-body research magnets. To date this problem has been addressed by restricting an extensive zone around the unshielded magnet or by placing external unsaturated iron shi...

journal_title：Magnetic resonance in medicine

authors： Huson FR,Bryan RN,MacKay WW,Herrick RC,Colvin J,Ford JJ,Pissanetzky S,Plishker GA,Rocha R,Schmidt W

更新日期：1993-01-01 00:00:00

abstract：PURPOSE:Respiratory motion makes hepatic ablation using high intensity focused ultrasound (HIFO) challenging. Previous HIFU liver treatment had required apnea induced during general anesthesia. We describe and test a system that allows treatment of the liver in the presence of breathing motion. METHODS:Mapping a signa...

journal_title：Magnetic resonance in medicine

authors： Holbrook AB,Ghanouni P,Santos JM,Dumoulin C,Medan Y,Pauly KB

更新日期：2014-02-01 00:00:00

abstract：:We have noninvasively produced low-resolution, quantitative nuclear magnetic resonance images of cerebral blood flow in 2-ml voxels in eight cats. Typical signal-to-noise of 4 to 1 was obtained in cerebral voxels in 16.5-s epochs. Mean flow during normocapnia (paCO2 = 39 +/- 4 mm Hg) and hypercapnia (paCO2 = 62 +/- 4 ...

journal_title：Magnetic resonance in medicine

authors： Branch CA,Ewing JR,Helpern JA,Ordidge RJ,Butt S,Welch KM

更新日期：1992-11-01 00:00:00

abstract：:A novel and automated technique is described for removing fMRI image artifacts resulting from motion outside of the imaging field of view. The technique is based on the Stockwell transform (ST), a mathematical operation that provides the frequency content at each time point within a time-varying signal. Using this tec...

journal_title：Magnetic resonance in medicine

authors： Goodyear BG,Zhu H,Brown RA,Mitchell JR

更新日期：2004-01-01 00:00:00

abstract：PURPOSE:Magnetization transfer ratio (MTR) histograms are used widely for the assessment of diffuse pathological changes in the brain. For broad clinical application, MTR scans should not only be fast, but confounding factors should also be minimized for high reproducibility. To this end, a 1-minute whole-brain spiral ...

journal_title：Magnetic resonance in medicine

authors： Afshari R,Santini F,Heule R,Meyer CH,Pfeuffer J,Bieri O

更新日期：2020-12-08 00:00:00

abstract：:Manipulation of the data describing two-dimensional magnetic resonance (MR) images can be used to zoom an image, decrease image noise and artifacts by modeling, or emphasize object edges in the field of view. In this paper, a two-dimensional band-selectable digital filtering (2D-BSDF) technique is detailed. This can b...

journal_title：Magnetic resonance in medicine

authors： Mitchell DK,Nichols ST,Smith MR,Scott K

更新日期：1989-03-01 00:00:00

abstract：:Combined MRI and 3D spectroscopic imaging (MRI/3D-MRSI) was used to study the metabolic effects of hormone-deprivation therapy in 65 prostate cancer patients, who underwent either short, intermediate, or long-term therapy, compared to 30 untreated control patients. There was a significant time-dependent loss of the pr...

journal_title：Magnetic resonance in medicine

authors： Mueller-Lisse UG,Swanson MG,Vigneron DB,Hricak H,Bessette A,Males RG,Wood PJ,Noworolski S,Nelson SJ,Barken I,Carroll PR,Kurhanewicz J

更新日期：2001-07-01 00:00:00

abstract：:Functional MRI (fMRI) was used to assess proprioceptive-associated cervical cord activity in 24 relapsing multiple sclerosis (MS) patients and 10 controls. Cord and brain conventional and diffusion tensor (DT) MRI were also acquired. fMRI was performed using a block design during a proprioceptive stimulation consistin...

journal_title：Magnetic resonance in medicine

authors： Agosta F,Valsasina P,Rocca MA,Caputo D,Sala S,Judica E,Stroman PW,Filippi M

更新日期：2008-05-01 00:00:00

abstract：:The orientation dependence of the free induction decay (FID) of 1H NMR water signal in ex vivo bovine digital flexor tendon at the native level of hydration is reported. Residual dipolar coupling due to the overall tissue anisotropy produces a 6:1 change in the signal intensity as an angle between the long axis of a s...

journal_title：Magnetic resonance in medicine

authors： Krasnosselskaia LV,Fullerton GD,Dodd SJ,Cameron IL

更新日期：2005-08-01 00:00:00

abstract：PURPOSE:All methods presented to date to map both conductivity and permittivity rely on multiple acquisitions to compute quantitatively the magnitude of radiofrequency transmit fields, B1+. In this work, we propose a method to compute both conductivity and permittivity based solely on relative receive coil sensitivitie...

journal_title：Magnetic resonance in medicine

authors： Marques JP,Sodickson DK,Ipek O,Collins CM,Gruetter R

更新日期：2015-07-01 00:00:00

abstract：PURPOSE:Anisotropic transverse R2 (1/T2 ) relaxation of water proton is sensitive to cartilage degenerative changes. The purpose is to develop an efficient method to extract this relaxation metric in clinical studies. METHODS:Anisotropic R2 can be measured inefficiently by standard R2 mapping after removing an isotrop...

journal_title：Magnetic resonance in medicine

authors： Pang Y,Palmieri-Smith RM,Malyarenko DI,Swanson SD,Chenevert TL

更新日期：2019-06-01 00:00:00

abstract：:Imaging delayed hyperenhancement of myocardial infarction is most commonly performed using an inversion recovery (IR) prepared 2D breathhold segmented k-space gradient echo (FGRE) sequence. Since only one slice is acquired per breathhold in this technique, 12-16 successive breathholds are required for complete anatomi...

journal_title：Magnetic resonance in medicine

authors： Saranathan M,Rochitte CE,Foo TK

更新日期：2004-05-01 00:00:00