Generalized MR interferography.

abstract：:Intrascan subject movement in clinical MR spectroscopic examinations may result in inconsistent water suppression that distorts the metabolite signals, frame-to-frame variations in spectral phase and frequency, and consequent reductions in the signal-to-noise ratio due to destructive averaging. Frame-to-frame phase/fr...

journal_title：Magnetic resonance in medicine

authors： Lin JM,Tsai SY,Liu HS,Chung HW,Mulkern RV,Cheng CM,Yeh TC,Chen NK

更新日期：2009-12-01 00:00:00

abstract：:Fitting a model to an experimental spectrum is a difficult nonlinear estimation problem. The solution presented here is to start an iterative search procedure sufficiently close to the optimal model parameter set. This is achieved by providing tissue-dependent a priori peak information and by a novel correlation metho...

journal_title：Magnetic resonance in medicine

authors： Burger C,McKinnon G,Buchli R,Boesiger P

更新日期：1991-10-01 00:00:00

abstract：:Subject motion during scan is a major source of artifacts in MR examinations. Prospective motion correction is a promising technique that tracks subject motion and adjusts the imaging volume in real time; however, additional retrospective correction may be necessary to achieve robust image quality and compatibility wi...

journal_title：Magnetic resonance in medicine

authors： Banerjee S,Beatty PJ,Zhang JZ,Shankaranarayanan A

更新日期：2013-02-01 00:00:00

abstract：:A single breath-hold 3D cardiac phase resolved steady-state free precession (SSFP) sequence was developed, allowing 3D visualization of the moving coronary arteries. A 3D stack of spirals was acquired continuously throughout the cardiac cycle, and a sliding window reconstruction was used to achieve high temporal resol...

journal_title：Magnetic resonance in medicine

authors： Kressler B,Spincemaille P,Nguyen TD,Cheng L,Xi Hai Z,Prince MR,Wang Y

更新日期：2007-09-01 00:00:00

abstract：:Magnetic resonance images of the lungs of a guinea pig have been produced using hyperpolarized helium as the source of the MR signal. The resulting images are not yet sufficiently optimized to reveal fine structural detail within the lung, but the spectacular signal from this normally signal-deficient organ system off...

journal_title：Magnetic resonance in medicine

authors： Middleton H,Black RD,Saam B,Cates GD,Cofer GP,Guenther R,Happer W,Hedlund LW,Johnson GA,Juvan K

更新日期：1995-02-01 00:00:00

abstract：:Chemical shift imaging benefits from signal-to-noise ratio (SNR) and chemical shift dispersion increases at stronger main field such as 7 Tesla, but the associated shorter radiofrequency (RF) wavelengths encountered require B1+ mitigation over both the spatial field of view (FOV) and a specified spectral bandwidth. Th...

journal_title：Magnetic resonance in medicine

authors： Setsompop K,Alagappan V,Gagoski BA,Potthast A,Hebrank F,Fontius U,Schmitt F,Wald LL,Adalsteinsson E

更新日期：2009-02-01 00:00:00

abstract：PURPOSE:In contrast to conventional linear gradients, gradient coil arrays with arbitrary spatial dependency might experience strong mutual coupling. Although conventional gradient power amplifiers with feedback loop might compensate the effect of coupling, required voltages for the compensation are generally unknown a...

journal_title：Magnetic resonance in medicine

authors： Ertan K,Taraghinia S,Atalar E

更新日期：2019-09-01 00:00:00

abstract：PURPOSE:Spiral readouts combine several favorable properties that promise superior net sensitivity for diffusion imaging. The purpose of this study is to verify the signal-to-noise ratio (SNR) benefit of spiral acquisition in comparison with current echo-planar imaging (EPI) schemes. METHODS:Diffusion-weighted in vivo...

journal_title：Magnetic resonance in medicine

authors： Lee Y,Wilm BJ,Brunner DO,Gross S,Schmid T,Nagy Z,Pruessmann KP

更新日期：2021-04-01 00:00:00

abstract：:To investigate white matter (WM) development, voxelwise analyses of diffusion tensor MRI (DTMRI) data, acquired from 12 very preterm and 11 preterm infants with gestational ages (GA) ranging from 25 to 29 and 29 to 32 weeks, respectively, and 10 newborn normal term infants were performed. T(2) relaxation measures were...

journal_title：Magnetic resonance in medicine

authors： Rose SE,Hatzigeorgiou X,Strudwick MW,Durbridge G,Davies PS,Colditz PB

更新日期：2008-10-01 00:00:00

abstract：:Phase-sensitive inversion-recovery (PSIR) imaging may provide enhanced T(1) contrast. However, clinical implementation of PSIR imaging is hindered because image reconstruction with this method often lacks robustness and requires manual intervention, particularly for data acquired in multiple slices and with phased-arr...

journal_title：Magnetic resonance in medicine

authors： Ma J

更新日期：2005-04-01 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：:Fucose is believed to be a marker for cancer that may be detectable by the 2D proton NMR (COSY) of human plasma. However, the COSY technique is time consuming and prone to error. These problems may be alleviated by using the SUPERCOSY pulse sequence; this technique shows that there are many other cross peaks in the re...

journal_title：Magnetic resonance in medicine

authors： Phillips PS,Herring FG

更新日期：1990-07-01 00:00:00

abstract：:MR-thermometry allows monitoring of the local temperature evolution during minimally invasive interventional therapies. However, for the particular case of MR-thermometry in the human breast, magnetic field variations induced by the respiratory cycle lead to phase fluctuations requiring a suitable correction strategy ...

journal_title：Magnetic resonance in medicine

authors： Hey S,Maclair G,de Senneville BD,Lepetit-Coiffe M,Berber Y,Köhler MO,Quesson B,Moonen CT,Ries M

更新日期：2009-06-01 00:00:00

abstract：:19F NMR imaging of the perfluorocarbon emulsion Fluosol has been used to study regional variations in oxygen tension in rat liver and spleen. We have used the linear dependence of spin lattice relaxation rate (1/T1) on the partial oxygen pressure (pO2) of Fluosol to determine the oxygen tension in the reticuloendothel...

journal_title：Magnetic resonance in medicine

authors： Holland SK,Kennan RP,Schaub MM,D'Angelo MJ,Gore JC

更新日期：1993-04-01 00:00:00

abstract：:A cerebrospinal fluid (CSF)-suppressed flow-attenuated inversion recovery (FLAIR) double-shot diffusion echo-planar imaging (EPI) sequence was developed and used, along with a non-CSF-suppressed version of the sequence, to determine the extent of the contribution of CSF partial-volume averaging to the apparent diffusi...

journal_title：Magnetic resonance in medicine

authors： Falconer JC,Narayana PA

更新日期：1997-01-01 00:00:00

abstract：:It is demonstrated that a high-resolution (1)H NMR spectrum of excised rat liver can be obtained using the technique of magic angle turning (MAT) at a sample spinning rate of 1 Hz. A variant of the phase-corrected MAT (PHORMAT) pulse sequence that includes a water suppression segment was developed for the investigatio...

journal_title：Magnetic resonance in medicine

authors： Hu JZ,Rommereim DN,Wind RA

更新日期：2002-05-01 00:00:00

abstract：PURPOSE:To develop the simultaneous acquisition of multiple voxels in localized MR spectroscopy (MRS) using sensitivity encoding, allowing reduced total scan time compared to conventional sequential single voxel (SV) acquisition methods. METHODS:Dual volume localization was used to simultaneously excite voxels in both...

journal_title：Magnetic resonance in medicine

authors： Boer VO,Klomp DW,Laterra J,Barker PB

更新日期：2015-09-01 00:00:00

abstract：PURPOSE:The primary purpose of this study is to propose a method for the simultaneous quantitative three-dimensional (3D) mapping of conductivity and susceptibility using double-echo ultrashort echo time (UTE) imaging. The secondary purpose is to investigate the changes of these properties over time during in vitro hem...

journal_title：Magnetic resonance in medicine

authors： Gho SM,Shin J,Kim MO,Kim DH

更新日期：2016-07-01 00:00:00

abstract：:A method is described for multislice imaging by means of rf pulses which contain a multifrequency excitation spectrum. These pulses label each slice by an individual signal phase and allow the separation of the signals from all the slices by subsequent add/subtract procedures. The image sensitivity corresponds to the ...

journal_title：Magnetic resonance in medicine

authors： Müller S

更新日期：1988-03-01 00:00:00

abstract：:A double-tuned single coil probe for high field metabolic NMR studies has been designed and tested. The resonant coil is a single-turn of copper foil wound on a quartz cylinder. It is fed by a short length of parallel strip line made of the same material; the feeder is also used as a tuning capacitance. Electrical par...

journal_title：Magnetic resonance in medicine

authors： Najim E,Grivet JP

更新日期：1992-02-01 00:00:00

abstract：:Vascular-space-occupancy (VASO) MRI exploits the difference between blood and tissue T1 to null blood signal and measure cerebral blood volume changes using the residual tissue signal. VASO imaging is more difficult at higher field because of sensitivity loss due to the convergence of tissue and blood T1 values and in...

journal_title：Magnetic resonance in medicine

authors： Hua J,Jones CK,Qin Q,van Zijl PC

更新日期：2013-04-01 00:00:00

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：:In the ongoing quest for faster imaging and higher spatial resolution, several methods have been developed to speed up data acquisition by incorporating prior information about the object being imaged. This study shows that many of these methods can be integrated into a single common equation. The unified framework pr...

journal_title：Magnetic resonance in medicine

authors： Tsao J,Behnia B,Webb AG

更新日期：2001-10-01 00:00:00

abstract：:The preovulatory rat follicle reaches a diameter of 1 mm with no internal blood vessels. Nutrient supply to the enclosed oocyte depends solely on passive diffusion across the follicular wall and the follicular fluid. Spin-echo and stimulated-echo NMR microscopy experiments were applied here for studying modulations in...

journal_title：Magnetic resonance in medicine

authors： Tempel C,Schiffenbauer YS,Meir G,Neeman M

更新日期：1995-08-01 00:00:00

abstract：:In a research environment, a magnetic resonance imaging system's manufacturer-supplied protection against excessive rf power deposition in the sample is often compromised. This paper presents a widely applicable scheme, based on a commonly available fuse, that simply and effectively limits the average rf power into a ...

journal_title：Magnetic resonance in medicine

authors： Hedges LK

更新日期：1989-02-01 00:00:00

abstract：PURPOSE:To validate an automatic algorithm for offline T2* measurements, providing robust, vendor-independent T2*, and uncertainty estimates for iron load quantification in the heart and liver using clinically available imaging sequences. METHODS:A T2* region of interest (ROI)-based algorithm was developed for robustn...

journal_title：Magnetic resonance in medicine

authors： Bidhult S,Xanthis CG,Liljekvist LL,Greil G,Nagel E,Aletras AH,Heiberg E,Hedström E

更新日期：2016-04-01 00:00:00

abstract：:For MR applications such as contrast-enhanced MR angiography, it is desirable to achieve simultaneously high spatial and temporal resolution. The current clinical standard uses view-sharing methods combined with parallel imaging; however, this approach still provides limited spatial and temporal resolution. To improve...

journal_title：Magnetic resonance in medicine

authors： Wang K,Busse RF,Holmes JH,Beatty PJ,Brittain JH,Francois CJ,Reeder SB,Du J,Korosec FR

更新日期：2011-08-01 00:00:00

abstract：:We studied the fluxes of a potassium congener (Rb(+)) in mouse hearts by (87)Rb MRS at 8.4T. The hearts were loaded with Rb(+) by perfusion with Krebs-Henseleit buffer, in which 50% of K(+) was substituted with Rb(+). We initiated Rb(+) efflux by changing the perfusion medium to Rb(+)-free buffer. Spectra were acquire...

journal_title：Magnetic resonance in medicine

authors： Jilkina O,Xiang B,Kuzio B,Rendell J,Kupriyanov VV

更新日期：2005-05-01 00:00:00

abstract：:In numerical analyses of radiofrequency (RF) fields for MRI, RF power is often permitted to radiate out of the problem region. In reality, RF power will be confined by the magnet bore and RF screen enclosing the magnet room. We present numerical calculations at different frequencies for various surface and volume coil...

journal_title：Magnetic resonance in medicine

authors： Liu W,Kao CP,Collins CM,Smith MB,Yang QX

更新日期：2013-01-01 00:00:00

abstract：:Algorithms to reliably detect motion in navigator echoes are crucial to many MRI motion suppression techniques. The accuracy of these algorithms is affected by noise and deformation of navigator echo profile caused by physiologic motion. This study compared the performance of algorithms based on correlation and least ...

journal_title：Magnetic resonance in medicine

authors： Wang Y,Grimm RC,Felmlee JP,Riederer SJ,Ehman RL

更新日期：1996-07-01 00:00:00