Investigation of human cervical and upper thoracic spinal cord motion: implications for imaging spinal cord structure and function.

abstract：PURPOSE:Spectrally selective "prewinding" radiofrequency pulses can counteract B0 inhomogeneity in steady-state sequences, but can only prephase a limited range of off-resonance. We propose spectral-spatial small-tip angle prewinding pulses that increase the off-resonance bandwidth that can be successfully prephased by...

journal_title：Magnetic resonance in medicine

authors： Williams SN,Nielsen JF,Fessler JA,Noll DC

更新日期：2018-03-01 00:00:00

abstract：:Transmit and receive RF coil arrays have proven to be particularly beneficial for ultra-high-field MR. Transmit coil arrays enable such techniques as B(1) (+) shimming to substantially improve transmit B(1) homogeneity compared to conventional volume coil designs, and receive coil arrays offer enhanced parallel imagin...

journal_title：Magnetic resonance in medicine

authors： Adriany G,Auerbach EJ,Snyder CJ,Gözübüyük A,Moeller S,Ritter J,Van de Moortele PF,Vaughan T,Uğurbil K

更新日期：2010-06-01 00:00:00

abstract：:We describe a versatile NMR probe that is designed for a variety of in vivo spectroscopic studies on small animals in vertical wide-bore magnets. Replaceable brackets enable the coils to be exchanged readily in order to observe 1H, 13C, 31P, and other nuclei, and to carry out double-resonance experiments. Two solenoid...

journal_title：Magnetic resonance in medicine

authors： Lyon RC,Tschudin RG,Daly PF,Cohen JS

更新日期：1988-01-01 00:00:00

abstract：:We developed a live high-field multiple-mouse magnetic resonance imaging method to increase the throughput of imaging studies involving large numbers of mice. Phantom experiments were performed in 7 shielded radiofrequency (RF) coils for concurrent imaging on a 7 Tesla MRI scanner outfitted with multiple transmit and ...

journal_title：Magnetic resonance in medicine

authors： Bock NA,Nieman BJ,Bishop JB,Mark Henkelman R

更新日期：2005-11-01 00:00:00

abstract：:The somatotopical organization of the human somatosensory cortex was analyzed with echo-planar imaging at 1.5 Tesla, utilizing deoxyhemoglobin as an endogenous contrast medium. Scrubbing stimulation at a frequency of 3 Hz was applied to one of three cutaneous areas: toes, fingertips, and tongue tip. Parasagittal echo-...

journal_title：Magnetic resonance in medicine

authors： Sakai K,Watanabe E,Onodera Y,Itagaki H,Yamamoto E,Koizumi H,Miyashita Y

更新日期：1995-05-01 00:00:00

abstract：:A magnetic resonance imaging (MRI) method is presented to detect, localize, and quantify myocardial kinematics by measuring the material rate-of-strain tensor at each pixel in gated NMR images of the heart. The immediate, local effect of muscular activity is self-deformation, and the strain tensor is the basic mathema...

journal_title：Magnetic resonance in medicine

authors： Wedeen VJ

更新日期：1992-09-01 00:00:00

abstract：:Homogeneous soft tissue, as regards its magnetic relaxation properties, is well-modeled by solutions of cross-linked protein (see Koenig and Brown, Prog. NMR Spectr. 22, 487 (1991)). Interactions at the solute-solvent interface alter the hydrodynamics of solvent water, and also couple the solute and solvent proton Zee...

journal_title：Magnetic resonance in medicine

authors： Koenig SH,Brown RD 3rd

更新日期：1993-12-01 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：:Functional MR imaging (fMRI) of activation in the brain is one of the more demanding applications required of an NMR imaging instrument. Since the signal changes in activation imaging are quite small, any instrumental variations can easily compromise the fMRI contrast. The authors describe a simple method for measurin...

journal_title：Magnetic resonance in medicine

authors： Weisskoff RM

更新日期：1996-10-01 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：:Longitudinal and transverse relaxation rates for the 11B resonances in sodium borocaptate (BSH) at varying concentrations were measured in undiluted horse serum in a 4.7 Tesla field. The results could be fit by a model that assumes fast exchange of the BSH molecule between a free and a bound state, using values of 0.7...

journal_title：Magnetic resonance in medicine

authors： Bendel P,Frantz A,Zilberstein J,Kabalka GW,Salomon Y

更新日期：1998-03-01 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：:Continuous arterial spin labeling (CASL) was used to obtain an index of cerebral blood flow (ICBF) in the normal mouse brain and in an orthotopic mouse model of human U87 high-grade glioma at 8.5 T. Under the assumption of a constant tissue:blood partition coefficient for water in different tissues, the mean ICBF (n =...

journal_title：Magnetic resonance in medicine

authors： Sun Y,Schmidt NO,Schmidt K,Doshi S,Rubin JB,Mulkern RV,Carroll R,Ziu M,Erkmen K,Poussaint TY,Black P,Albert M,Burstein D,Kieran MW

更新日期：2004-05-01 00:00:00

abstract：PURPOSE:The ultimate intrinsic signal-to-noise ratio (UISNR) is normally calculated using electrodynamic simulations with a complete basis of modes. Here, we provide an exact solution for the UISNR at the center of a dielectric sphere and assess how accurately this solution approximates UISNR away from the center. MET...

journal_title：Magnetic resonance in medicine

authors： Lee HH,Sodickson DK,Lattanzi R

更新日期：2018-11-01 00:00:00

abstract：:We describe a doubly tuned radiofrequency (RF) local coil probe designed specifically for performing in vivo image-localized spectroscopy. The probe was designed using principles developed in connection with the counter-rotating-current (CRC) and planar-pair loop gap resonators for magnetic resonance imaging (MRI). Th...

journal_title：Magnetic resonance in medicine

authors： Grist TM,Jesmanowicz A,Kneeland JB,Froncisz W,Hyde JS

更新日期：1988-03-01 00:00:00

abstract：:Myocardial tagging is a new noninvasive MRI method that allows the study of myocardial motion with high accuracy. However, with conventional tagging techniques tagging contrast is impaired at later heart phases due to longitudinal relaxation. An improved method, called Complementary SPAtial Modulation of Magnetization...

journal_title：Magnetic resonance in medicine

authors： Fischer SE,McKinnon GC,Maier SE,Boesiger P

更新日期：1993-08-01 00:00:00

abstract：:This report describes a noninvasive 1H-NMR method for measuring absolute temperatures (+/- 0.2 degrees C) in biological samples and, in particular, in cell culture perfusion systems, utilizing the linear temperature dependence of the water chemical shift relative to the temperature-independent shift of one of the comp...

journal_title：Magnetic resonance in medicine

authors： Lutz NW,Kuesel AC,Hull WE

更新日期：1993-01-01 00:00:00

abstract：:High-field MRI scanners are, in principle, well suited for mouse studies; however, many high-field magnets employ a vertical design that may influence the physiological state of the rodent. The purpose of this study was to investigate the orthostatic response of cerebral blood flow (CBF) in mice during a prolonged MR ...

journal_title：Magnetic resonance in medicine

authors： Foley LM,Hitchens TK,Kochanek PM,Melick JA,Jackson EK,Ho C

更新日期：2005-10-01 00:00:00

abstract：PURPOSE:To explore the temperature-induced signal change in two-dimensional multi-spectral imaging (2DMSI) for fast thermometry near metallic hardware to enable MR-guided focused ultrasound surgery (MRgFUS) in patients with implanted metallic hardware. METHOD:2DMSI was optimized for temperature sensitivity and applied...

journal_title：Magnetic resonance in medicine

authors： Weber H,Ghanouni P,Pascal-Tenorio A,Pauly KB,Hargreaves BA

更新日期：2018-07-01 00:00:00

abstract：PURPOSE:To map brain metabolites and tissue magnetic susceptibility simultaneously using a single three-dimensional 1 H-MRSI acquisition without water suppression. METHODS:The proposed technique builds on a subspace imaging method called spectroscopic imaging by exploiting spatiospectral correlation (SPICE), which ena...

journal_title：Magnetic resonance in medicine

authors： Peng X,Lam F,Li Y,Clifford B,Liang ZP

更新日期：2018-01-01 00:00:00

abstract：PURPOSE:To explore the effects of high permittivity dielectric pads on the transmit and receive characteristics of a 3 Tesla body coil centered at the thighs, and their implications on image uniformity in receive array applications. THEORY AND METHODS:Transmit and receive profiles of the body coil with and without die...

journal_title：Magnetic resonance in medicine

authors： Brink WM,Versluis MJ,Peeters JM,Börnert P,Webb AG

更新日期：2016-12-01 00:00:00

abstract：PURPOSE:To test the hypothesis that a noninvasive dynamic contrast enhanced MRI (DCE-MRI) derived interstitial volume fraction (ve ) and/or distribution volume (VD ) were correlated with tumor cellularity in cerebral tumor. METHODS:T1 -weighted DCE-MRI studies were performed in 18 athymic rats implanted with U251 xeno...

journal_title：Magnetic resonance in medicine

authors： Aryal MP,Nagaraja TN,Keenan KA,Bagher-Ebadian H,Panda S,Brown SL,Cabral G,Fenstermacher JD,Ewing JR

更新日期：2014-06-01 00:00:00

abstract：PURPOSE:Magnetic resonance imaging of humans at high magnetic field strengths is strongly influenced by the interference of the radiofrequency (RF) electromagnetic field and the body. To minimize this effect, multiple RF sources could be used. A novel setup (called multimode, coaxial waveguide) is proposed that facilit...

journal_title：Magnetic resonance in medicine

authors： Andreychenko A,Kroeze H,Boer VO,Lagendijk JJ,Luijten PR,van den Berg CA

更新日期：2014-04-01 00:00:00

abstract：:A fast, two-coil, pseudo-continuous labeling scheme is presented. This new scheme permits the collection of a multislice subtraction pair in <3 s, depending on the subject's arterial transit times. The method consists of acquiring both control and tag images immediately after a labeling period that matches the arteria...

journal_title：Magnetic resonance in medicine

authors： Hernandez-Garcia L,Lee GR,Vazquez AL,Noll DC

更新日期：2004-03-01 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 develop a fully automated trajectory and gradient waveform design for the non-Cartesian shells acquisition, and to develop a magnetization-prepared (MP) shells acquisition to achieve an efficient three-dimensional acquisition with improved gray-to-white brain matter contrast. METHODS:After reviewing the she...

journal_title：Magnetic resonance in medicine

authors： Shu Y,Tao S,Trzasko JD,Huston J 3rd,Weavers PT,Bernstein MA

更新日期：2018-04-01 00:00:00

abstract：:Magnetic resonance (MR) diffusion imaging is a useful technique with which to increase our understanding of pathologic damage to the central nervous system. To fully quantitate diffusion and anisotropy in the spinal cord, as in other tissues, it is necessary to determine the diffusion tensor. If spinal cord diffusion ...

journal_title：Magnetic resonance in medicine

authors： Clark CA,Werring DJ,Miller DH

更新日期：2000-01-01 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：:A demonstration of MR guided thermal surgery involved experiments with imaging of focused ultrasound in an MRI system, measurements of the thermal transients and a thermal analysis of the resulting images. Both the heat distribution and the creation of focused ultrasound lesions in gel phantoms, in vitro bovine muscle...

journal_title：Magnetic resonance in medicine

authors： Cline HE,Schenck JF,Watkins RD,Hynynen K,Jolesz FA

更新日期：1993-07-01 00:00:00

abstract：PURPOSE:At high field, T2 -weighted (T2 w) imaging is limited by transmit field inhomogeneity and increased radiofrequency power deposition. In this work, we introduce SAMPA (Slice-selective Adiabatic Magnetization T2 PrepAration) and demonstrate its use for efficient brain T2 w imaging at 7 Tesla (T). METHODS:SAMPA w...

journal_title：Magnetic resonance in medicine

authors： Dyvorne H,Balchandani P

更新日期：2016-12-01 00:00:00