Impact of incidental magnetization transfer effects on inversion-recovery sequences that use a fast spin-echo readout.

abstract：PURPOSE:A new approach to design parallel transmit (pTx) head arrays is proposed that integrates transmit radiofrequency pulse designs with electromagnetic modeling of array coil elements. THEORY AND METHODS:An approach to design pTx head arrays is proposed that finds optimal groupings of a large number of coils into ...

journal_title：Magnetic resonance in medicine

authors： Cao Z,Yan X,Gore JC,Grissom WA

更新日期：2020-06-01 00:00:00

abstract：PURPOSE:To present the results of the first human spinal cord in vivo MRI scans at 9.4T. METHODS:A human brain coil was used to image the human spinal cord at 9.4T. All anatomical images were acquired with a T2 *-weighted gradient-echo sequence. A comparison of the influence of four different B0 shimming routines on t...

journal_title：Magnetic resonance in medicine

authors： Geldschläger O,Bosch D,Avdievich NI,Henning A

更新日期：2021-02-01 00:00:00

abstract：PURPOSE:Establishing a framework to evaluate performances of prospective motion correction (PMC) MRI considering motion variability between MRI scans. METHODS:A framework was developed to obtain quantitative comparisons between different motion correction setups, considering that varying intrinsic motion patterns betw...

journal_title：Magnetic resonance in medicine

authors： Pannetier NA,Stavrinos T,Ng P,Herbst M,Zaitsev M,Young K,Matson G,Schuff N

更新日期：2016-02-01 00:00:00

abstract：:In an effort to develop MRI methods for the evaluation of tumor angiogenesis (new blood vessel formation), MRI-derived cerebral blood volume (CBV) information has been compared to histologic measures of microvessel density (MVD). Although MVD is a standard marker of angiogenesis, it is not a direct correlate of the vo...

journal_title：Magnetic resonance in medicine

authors： Pathak AP,Schmainda KM,Ward BD,Linderman JR,Rebro KJ,Greene AS

更新日期：2001-10-01 00:00:00

abstract：PURPOSE:Magnetically labeled cells and tissue iron deposits provide qualitative means to detect and monitor cardiovascular and cerebrovascular diseases with magnetic resonance imaging. However, to quantitatively examine the extent of pathological micromorphological changes, detailed knowledge about microstructural para...

journal_title：Magnetic resonance in medicine

authors： Kurz FT,Kampf T,Heiland S,Bendszus M,Schlemmer HP,Ziener CH

更新日期：2014-05-01 00:00:00

abstract：:Dynamic contrast-enhanced MRI data in vertebral bone marrow (vBM) are currently analyzed with descriptive indices. The purpose of this study was to develop and evaluate a quantitative approach, considering the tissue composition of vBM. Therefore, a measurement of the water fraction, f(wat), and the precontrast relaxa...

journal_title：Magnetic resonance in medicine

authors： Biffar A,Sourbron S,Schmidt G,Ingrisch M,Dietrich O,Reiser MF,Baur-Melnyk A

更新日期：2010-07-01 00:00:00

abstract：:A method for calculating quantitative three-dimensional susceptibility maps from field measurements acquired using gradient echo imaging at high field is presented. This method is based on division of the three-dimensional Fourier transforms of high-pass-filtered field maps by a simple function that is the Fourier tra...

journal_title：Magnetic resonance in medicine

authors： Wharton S,Schäfer A,Bowtell R

更新日期：2010-05-01 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：:An electron paramagnetic resonance image was measured for the first time from in vivo field gradient spectra of a living murine tumor (Cloudman S-91 melanoma in the tail of a DBA-2J mouse) using the paramagnetic nitroxide imaging agent 3-carboxamido-2,2,5,5-tetramethylpyrroline-1-oxyl injected into the tail vein. The ...

journal_title：Magnetic resonance in medicine

authors： Berliner LJ,Fujii H,Wan XM,Lukiewicz SJ

更新日期：1987-04-01 00:00:00

abstract：:Human cardiac 31P nuclear magnetic resonance (NMR) spectra are usually quantified in relative terms, i.e., the ratio of metabolite signals is calculated. If 31P NMR spectroscopy of the heart is to emerge as a clinically relevant diagnostic modality, reliable quantification of absolute concentrations of 31P metabolites...

journal_title：Magnetic resonance in medicine

authors： Meininger M,Landschütz W,Beer M,Seyfarth T,Horn M,Pabst T,Haase A,Hahn D,Neubauer S,von Kienlin M

更新日期：1999-04-01 00:00:00

abstract：:The reconstruction of MR images from nonrectilinearly sampled data is complicated by the fact that the inverse 2D Fourier transform (FT) cannot be performed directly on the acquired k-space data set. k-Space gridding is commonly used because it is an efficient reconstruction method. However, conventional gridding requ...

journal_title：Magnetic resonance in medicine

authors： Moriguchi H,Duerk JL

更新日期：2004-02-01 00:00:00

abstract：:In vivo MR spectroscopy (MRS) studies have shown reductions in NAA/Cr levels in patients with severe neurocognitive deficits due to AIDS dementia complex (ADC), also known as neuroAIDS. The relationship between the cellular changes within the brain during neuroAIDS and the role of NAA/Cr as a metabolic marker remains ...

journal_title：Magnetic resonance in medicine

authors： Lentz MR,Westmoreland SV,Lee V,Ratai EM,Halpern EF,González RG

更新日期：2008-03-01 00:00:00

abstract：PURPOSE:T2 -weighted sequences are particularly sensitive to the radiofrequency (RF) field inhomogeneity problem at ultra-high-field because of the errors accumulated by the imperfections of the train of refocusing pulses. As parallel transmission (pTx) has proved particularly useful to counteract RF heterogeneities, u...

journal_title：Magnetic resonance in medicine

authors： Gras V,Mauconduit F,Vignaud A,Amadon A,Le Bihan D,Stöcker T,Boulant N

更新日期：2018-07-01 00:00:00

abstract：:As a high-speed imaging technique based on stimulated echoes single-shot STEAM MRI is insensitive to chemical shift artifacts and magnetic susceptibility differences. The achievable signal-to-noise ratio (SNR) is limited by the fact that high flip angles of the read-out excitation pulses cause a steep decay of the sti...

journal_title：Magnetic resonance in medicine

authors： Finsterbusch J,Frahm J

更新日期：2002-03-01 00:00:00

abstract：:A novel iterative k-space data-driven technique, namely parallel reconstruction using null operations (PRUNO), is presented for parallel imaging reconstruction. In PRUNO, both data calibration and image reconstruction are formulated into linear algebra problems based on a generalized system model. An optimal data cali...

journal_title：Magnetic resonance in medicine

authors： Zhang J,Liu C,Moseley ME

更新日期：2011-11-01 00:00:00

abstract：PURPOSE:Single-scan two-dimensional MRI has been generally constrained to acquisitions in high quality magnets. This study introduces a methodology, cross-term spatiotemporal encoding (xSPEN), that delivers such images under much poorer external field conditions. METHODS:xSPEN departs from conventional k-space scannin...

journal_title：Magnetic resonance in medicine

authors： Zhang Z,Seginer A,Frydman L

更新日期：2017-02-01 00:00:00

abstract：PURPOSE:A new T1 mapping method is proposed that is accurate, rapid, and robust to motion. Considering these features, the method is dubbed "T-One with Enhanced Robustness and Speed (TOWERS)." METHODS:TOWERS is composed of inversion recovery (IR) and saturation recovery (SR) acquisitions. In the IR acquisitions, a sli...

journal_title：Magnetic resonance in medicine

authors： Eldeniz C,Finsterbusch J,Lin W,An H

更新日期：2016-07-01 00:00:00

abstract：:Flow-sensitive dephasing (FSD) magnetization preparation has been developed for black-blood vessel wall MRI and noncontrast MR angiography. The first-order gradient moment, m(1) , is a measure of the flow-sensitization imparted by an FSD preparative module. Determination of the optimal m(1) for each individual is high...

journal_title：Magnetic resonance in medicine

authors： Fan Z,Zhou X,Bi X,Dharmakumar R,Carr JC,Li D

更新日期：2011-04-01 00:00:00

abstract：:Magnetoferritin nanoparticles have been developed as high-relaxivity, functional contrast agents for MRI. Several previous techniques have relied on unloading native ferritin and re-incorporation of iron into the core, often resulting in a polydisperse sample. Here, a simplified technique is developed using commercial...

journal_title：Magnetic resonance in medicine

authors： Jordan VC,Caplan MR,Bennett KM

更新日期：2010-11-01 00:00:00

abstract：:Cortical spreading depression (CSD) was visualized using manganese-enhanced MRI (MEMRI) following topical application of KCl to the exposed rat cortex. MEMRI signal increase in the ipsilateral cortex relative to the contralateral control region was 60 +/- 30% following two KCl applications. MEMRI signal increase for a...

journal_title：Magnetic resonance in medicine

authors： Henning EC,Meng X,Fisher M,Sotak CH

更新日期：2005-04-01 00:00:00

abstract：:1H MR spectra were recorded from human gastrocnemius muscle at 63.86 MHz using the body coil of the Signa scanner as transmitter and a 3-in. surface coil as receiver. The fat content of the muscle was quantified relative to that of water in a selected volume or slice. The fat/water ratio was 0.05-0.07 for normal muscl...

journal_title：Magnetic resonance in medicine

authors： Bárány M,Venkatasubramanian PN,Mok E,Siegel IM,Abraham E,Wycliffe ND,Mafee MF

更新日期：1989-05-01 00:00:00

abstract：PURPOSE:To demonstrate feasibility of exploiting the spatial distribution of off-resonance surrounding metallic implants for accelerating multispectral imaging techniques. THEORY AND METHODS:Multispectral imaging (MSI) techniques perform time-consuming independent three-dimensional acquisitions with varying radio freq...

journal_title：Magnetic resonance in medicine

authors： Smith MR,Artz NS,Koch KM,Samsonov A,Reeder SB

更新日期：2014-12-01 00:00:00

abstract：PURPOSE:To develop a novel, simultaneous multislice reconstruction method that exploits Hankel subspace learning (SMS-HSL) for aliasing separation in the slice direction. METHODS:An SMS signal model with the Hankel-structured matrix was proposed. To efficiently suppress interslice leakage artifacts from a signal subsp...

journal_title：Magnetic resonance in medicine

authors： Park S,Park J

更新日期：2017-10-01 00:00:00

abstract：PURPOSE:Cardiac T1 mapping has become an increasingly important imaging technique, contributing novel diagnostic options. However, currently utilized methods are often associated with accuracy problems because of heart rate variations and cardiac arrhythmia, limiting their value in clinical routine. This study aimed to...

journal_title：Magnetic resonance in medicine

authors： Gensler D,Salinger T,Düring M,Lorenz K,Jahns R,Wech T,Frantz S,Ertl G,Jakob PM,Nordbeck P

更新日期：2019-03-01 00:00:00

abstract：:Pulsed arterial spin labeling (ASL) techniques provide a noninvasive method of obtaining qualitative and quantitative perfusion images with MRI. ASL techniques employ inversion recovery and/or saturation recovery to induce perfusion weighting, and thus the performance of these techniques is dependent on the slice prof...

journal_title：Magnetic resonance in medicine

authors： Keilholz-George SD,Knight-Scott J,Berr SS

更新日期：2001-07-01 00:00:00

abstract：:Formalin fixation of tissue is a common laboratory practice. A direct comparison of diffusion tensor imaging (DTI) parameters from mouse brains before (in vivo) and after (ex vivo) formalin fixation is reported herein. Five diffusion indices were examined in a cohort of seven mice: relative anisotropy (RA), directiona...

journal_title：Magnetic resonance in medicine

authors： Sun SW,Neil JJ,Song SK

更新日期：2003-10-01 00:00:00

abstract：:Optimization of experimental settings of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), like the contrast administration protocol, is of great importance for reliable quantification of the microcirculatory properties, such as the volume transfer-constant K(trans). Using system identification theory an...

journal_title：Magnetic resonance in medicine

authors： Aerts HJ,van Riel NA,Backes WH

更新日期：2008-05-01 00:00:00

abstract：:An arterial spin labeling technique using separate RF labeling and imaging coils was used to obtain multislice perfusion images of the human brain at 3 T. Continuous RF irradiation at a peak power of 0.3 W was applied to the carotid arteries to adiabatically invert spins. Labeling was achieved without producing magnet...

journal_title：Magnetic resonance in medicine

authors： Zaharchuk G,Ledden PJ,Kwong KK,Reese TG,Rosen BR,Wald LL

更新日期：1999-06-01 00:00:00

abstract：:The mechanism behind previously observed changes in the apparent diffusion coefficient (ADC) during brain activation is not well understood. Therefore, we investigated the signal source and spatial specificity of functional magnetic resonance imaging (fMRI) ADC changes systematically in the visual cortex of cats using...

journal_title：Magnetic resonance in medicine

authors： Jin T,Zhao F,Kim SG

更新日期：2006-12-01 00:00:00

abstract：PURPOSE:Dipole antennas in ultrahigh field MRI have demonstrated advantages over more conventional designs. In this study, the fractionated dipole antenna is presented: a dipole where the legs are split into segments that are interconnected by capacitors or inductors. METHODS:A parameter study has been performed on di...

journal_title：Magnetic resonance in medicine

authors： Raaijmakers AJ,Italiaander M,Voogt IJ,Luijten PR,Hoogduin JM,Klomp DW,van den Berg CA

更新日期：2016-03-01 00:00:00