Water and fat MR imaging with chemical shift selective 3D steady state methods.

abstract：:Coronal proton and sodium images of control rats and rats with either increased permeability edema produced by intravenous alloxan (300 mg/kg) or increased pressure edema produced by saline infusion (2 ml/min) were obtained. Axial chest CT images were used to monitor the development of pulmonary edema. Immediately aft...

journal_title：Magnetic resonance in medicine

authors： Kundel HL,Shetty A,Joseph PM,Summers RM,Kassab EA,Moore B

更新日期：1988-04-01 00:00:00

abstract：:A technique for reconstructing dynamic undersampled MRI data, termed "x-f choice," was developed and applied to dynamic contrast-enhanced MR angiography (DCE-MRA). Regular undersampling in k-t space (a hybrid of k-space and time) creates aliasing in the conjugate x-f space that must be resolved. When regions in the ob...

journal_title：Magnetic resonance in medicine

authors： Malik SJ,Schmitz S,O'Regan D,Larkman DJ,Hajnal JV

更新日期：2006-10-01 00:00:00

abstract：:Diffusion-weighted imaging (DWI) is frequently used to diagnose stroke. However, the origin of the observed reduction in the apparent diffusion coefficient (ADC) in the acute phase following ischemia is not well understood. Although cell swelling is considered to play an important role, it is unclear whether this can ...

journal_title：Magnetic resonance in medicine

authors： van Pul C,Jennekens W,Nicolay K,Kopinga K,Wijn PF

更新日期：2005-02-01 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：:The analysis of abdominal and thoracic dynamic contrast-enhanced MRI is often impaired by artifacts and misregistration caused by physiological motion. Breath-hold is too short to cover long acquisitions. A novel multipurpose reconstruction technique, entitled dynamic contrast-enhanced generalized reconstruction by in...

journal_title：Magnetic resonance in medicine

authors： Filipovic M,Vuissoz PA,Codreanu A,Claudon M,Felblinger J

更新日期：2011-03-01 00:00:00

abstract：:This contribution reports the first direct and noninvasive observation of cerebral glucose in normal anesthetized rats (n = 16) using short-echo-time localized proton NMR spectroscopy (2.35 T, STEAM, TR = 6000 ms, TE = 20 ms, 125 microliters). In addition to resonances from N-acetyl aspartate (NAA), glutamate, total c...

journal_title：Magnetic resonance in medicine

authors： Gyngell ML,Michaelis T,Hörstermann D,Bruhn H,Hänicke W,Merboldt KD,Frahm J

更新日期：1991-06-01 00:00:00

abstract：PURPOSE:We sought to develop and test a clinically feasible 1-point Dixon, three-dimensional (3D) radial acquisition strategy to create isotropic 3D MR images of (129)Xe in the airspaces, barrier, and red blood cells (RBCs) in a single breath. The approach was evaluated in healthy volunteers and subjects with idiopathi...

journal_title：Magnetic resonance in medicine

authors： Kaushik SS,Robertson SH,Freeman MS,He M,Kelly KT,Roos JE,Rackley CR,Foster WM,McAdams HP,Driehuys B

更新日期：2016-04-01 00:00:00

abstract：PURPOSE:To achieve highly accelerated submillimeter resolution T 2 -weighted functional MRI at 7T by developing a three-dimensional gradient and spin echo imaging (GRASE) with inner-volume sel...

journal_title：Magnetic resonance in medicine

authors： Park S,Torrisi S,Townsend JD,Beckett A,Feinberg DA

更新日期：2020-11-24 00:00:00

abstract：:Parallel magnetic resonance imaging in k-space such as generalized auto-calibrating partially parallel acquisition exploits spatial correlation among neighboring signals over multiple coils in calibration to estimate missing signals in reconstruction. It is often challenging to achieve accurate calibration information...

journal_title：Magnetic resonance in medicine

authors： Park S,Park J

更新日期：2012-06-01 00:00:00

abstract：:Using a 32-echo imaging pulse sequence, T2 relaxation decay curves were acquired from five white- and six gray-matter brain structures outlined in 12 normal volunteers. The water contents of white and gray matter were 0.71 (0.01) and 0.83 (0.03) g/ml, respectively. All white-matter structures had significantly higher ...

journal_title：Magnetic resonance in medicine

authors： Whittall KP,MacKay AL,Graeb DA,Nugent RA,Li DK,Paty DW

更新日期：1997-01-01 00:00:00

abstract：PURPOSE:To assess volumetric proton MR spectroscopic imaging (MRSI) of the human brain on multivendor MRI instruments. METHODS:Echo-planar spectroscopic imaging was developed on instruments from three manufacturers, with matched specifications and acquisition protocols that accounted for differences in sampling perfor...

journal_title：Magnetic resonance in medicine

authors： Sabati M,Sheriff S,Gu M,Wei J,Zhu H,Barker PB,Spielman DM,Alger JR,Maudsley AA

更新日期：2015-11-01 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：PURPOSE:Over the last two decades, extended criteria have promoted an increased number of donor livers available for liver transplantation. But posttransplant graft loss is still a major concern. Macrovesicular hepatic steatosis (MHS) is recognized as the most significant prognostic histologic parameter in predicting p...

journal_title：Magnetic resonance in medicine

authors： Chen G,Jiang J,Wang X,Yang M,Xie Y,Guo H,Tang H,Zhou L,Hu D,Kamel IR,Chen Z,Li Z

更新日期：2020-11-16 00:00:00

abstract：:The effects of reducing the pulse repetition time from 2500 ms to 1000 ms when using spin-density-projection-assisted R2-magnetic resonance imaging for the purpose of measuring liver iron concentration were evaluated. Repeated liver R2 measurements were made using both protocols on 60 subjects with liver iron concentr...

journal_title：Magnetic resonance in medicine

authors： Pavitt HL,Aydinok Y,El-Beshlawy A,Bayraktaroglu S,Ibrahim AS,Hamdy MM,Pang W,Sharples C,St Pierre TG

更新日期：2011-05-01 00:00:00

abstract：:A regularized algorithm is presented for localized in vivo shimming. The technique uses first- (X,Y,Z), second- (Z(2), ZX, ZY, X(2)-Y(2), XY), and third-order (Z(3)) shim coils, and is robust when applied to arbitrarily-shaped, as well as off-center, regions of interest (ROIs). A single-shot spiral pulse sequence is u...

journal_title：Magnetic resonance in medicine

authors： Kim DH,Adalsteinsson E,Glover GH,Spielman DM

更新日期：2002-10-01 00:00:00

abstract：:Diffusion tensor imaging has been used in a number of spinal cord studies, but severe distortions caused by susceptibility induced field inhomogeneities limit its applicability to investigate small volumes within acceptable acquisition times. A way to evaluate image distortions is to map the point spread function of t...

journal_title：Magnetic resonance in medicine

authors： Lundell H,Barthelemy D,Biering-Sørensen F,Cohen-Adad J,Nielsen JB,Dyrby TB

更新日期：2013-01-01 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：:The relaxivities (R-values) of the gadolinium diethylene triamine pentaacetic acid (Gd(DTPA)2-) ions in a series of skim-milk solutions at 0-40% milk concentrations were measured using NMR spectroscopy. The R-value was found to be approximately linearly proportional to the concentration of the solid component in the m...

journal_title：Magnetic resonance in medicine

authors： Zheng S,Xia Y

更新日期：2010-01-01 00:00:00

abstract：:The intra-individual and inter-individual variations of the global N-acetylaspartate (NAA) concentration were measured in a cohort of five 42+/-5 year-old normal females. The total NAA signal from the whole head was obtained with non-localized non-echo proton spectroscopy (1H-MRS) and converted into absolute mole amou...

journal_title：Magnetic resonance in medicine

authors： Gonen O,Viswanathan AK,Catalaa I,Babb J,Udupa J,Grossman RI

更新日期：1998-11-01 00:00:00

abstract：:Single-slab 3D turbo/fast spin echo (SE) imaging with very long echo trains was recently introduced with slab selection using a highly selective excitation pulse and short, nonselective refocusing pulses with variable flip angles for high imaging efficiency. This technique, however, is vulnerable to image degradation ...

journal_title：Magnetic resonance in medicine

authors： Park J,Mugler JP 3rd,Hughes T

更新日期：2009-10-01 00:00:00

abstract：:A kinetic analysis of water signal intensity changes measured in human visual cortex by PRESS localized 1H spectroscopy at 500 ms resolution with light-emitting diode (LED) goggle stimulation was used to determine vascular transit times for transitions between rest and activation. Monoexponential curve fitting was use...

journal_title：Magnetic resonance in medicine

authors： Detre JA,Wang Z,Stecker MM,Zimmerman RA

更新日期：1995-09-01 00:00:00

abstract：:NMRD profiles, the magnetic field dependence of the water proton longitudinal relaxation rates, have been acquired for two new diphosphonate-modified GdDTPA complexes currently under evaluation as relaxation agents for the MRI detection of soft-tissue calcifications. Fresh dilute solutions show profiles identical to t...

journal_title：Magnetic resonance in medicine

authors： Adzamli IK,Blau M

更新日期：1991-01-01 00:00:00

abstract：:In this work, substrate selection was monitored in the left ventricle of the canine myocardium by following pyruvate and lactate oxidation under in vivo conditions at basal and elevated workloads. These studies were conducted in the open chest model using dynamic 13C NMR techniques in the presence and absence of dichl...

journal_title：Magnetic resonance in medicine

authors： Rath DP,Zhu H,Tong X,Jiang Z,Hamlin RL,Robitaille PM

更新日期：1997-12-01 00:00:00

abstract：:A three-axis uniplanar gradient coil was designed and built to provide order-of-magnitude increases in gradient strength of up to 500 mT/m on the x- and y-axes, and 1000 mT/m for the z-axis at 640 A input over a limited FOV ( approximately 16 cm) for superficial regions, compared to conventional gradient coils, with s...

journal_title：Magnetic resonance in medicine

authors： Aksel B,Marinelli L,Collick BD,Von Morze C,Bottomley PA,Hardy CJ

更新日期：2007-07-01 00:00:00

abstract：:Variable nutation SSFP (DESPOT2) permits rapid, high-resolution determination of the transverse (T2) relaxation constant. A limitation of DESPOT2, however, is the presence of T2 voids due to off-resonance banding artifacts associated with SSFP images. These artifacts typically occur in images acquired with long repeti...

journal_title：Magnetic resonance in medicine

authors： Deoni SC,Ward HA,Peters TM,Rutt BK

更新日期：2004-08-01 00:00:00

abstract：PURPOSE:Define criteria for selection of optimal flip angle sets for T1 estimation and evaluate effects on T1 mapping. THEORY AND METHODS:Flip angle sets for spoiled gradient echo-based T1 mapping were selected by minimizing T1 estimate variance weighted by the joint density of M0 and T1 in an initial acquisition. The...

journal_title：Magnetic resonance in medicine

authors： Lewis CM,Hurley SA,Meyerand ME,Koay CG

更新日期：2016-09-01 00:00:00

abstract：:A simple iterative algorithm, termed deconvolution-interpolation gridding (DING), is presented to address the problem of reconstructing images from arbitrarily-sampled k-space. The new algorithm solves a sparse system of linear equations that is equivalent to a deconvolution of the k-space with a small window. The dec...

journal_title：Magnetic resonance in medicine

authors： Gabr RE,Aksit P,Bottomley PA,Youssef AB,Kadah YM

更新日期：2006-12-01 00:00:00

abstract：:Healthy human brain diffusion anisotropy maps derived from standard spin echo diffusion tensor imaging (DTI) were compared with those using fluid-attenuated inversion recovery (FLAIR) preparation prior to DTI to null the signal from cerebrospinal fluid (CSF). Consistent comparisons entailed development of DTI postproc...

journal_title：Magnetic resonance in medicine

authors： Papadakis NG,Martin KM,Mustafa MH,Wilkinson ID,Griffiths PD,Huang CL,Woodruff PW

更新日期：2002-08-01 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：PURPOSE:To develop and demonstrate the feasibility of a new technique for respiratory-gated, fat-suppressed, three-dimensional spoiled gradient-recalled echo (3D-SPGR) with navigator gating for more accurate and robust motion detection. METHODS:A navigator-gated 3D-SPGR technique was modified to include a wait period ...

journal_title：Magnetic resonance in medicine

authors： Iwadate Y,Brau AC,Vasanawala SS,Kabasawa H

更新日期：2014-07-01 00:00:00