Low-power NMR volume selection by slicing z magnetization.

abstract：:The pulse wave velocity (PWV) of aortic blood flow is considered a surrogate for aortic compliance. A new method using phase-contrast (PC)-MRI is presented whereby the spatial and temporal profiles of axial velocity along the descending aorta can be analyzed. Seventeen young healthy volunteers (the YH group), six olde...

journal_title：Magnetic resonance in medicine

authors： Yu HY,Peng HH,Wang JL,Wen CY,Tseng WY

更新日期：2006-10-01 00:00:00

abstract：:Prepolarized MRI uses pulsed magnetic fields to produce MR images by polarizing the sample at one field strength (approximately 0.5 T) before imaging at a much lower field (approximately 50 mT). Contrast reflecting the T(1) of the sample at an intermediate field strength is achieved by polarizing the sample and then a...

journal_title：Magnetic resonance in medicine

authors： Ungersma SE,Matter NI,Hardy JW,Venook RD,Macovski A,Conolly SM,Scott GC

更新日期：2006-06-01 00:00:00

abstract：:The focal underdetermined system solver (FOCUSS) was originally designed to obtain sparse solutions by successively solving quadratic optimization problems. This article adapts FOCUSS for a projection reconstruction MR imaging problem to obtain high resolution reconstructions from angular under-sampled radial k-space ...

journal_title：Magnetic resonance in medicine

authors： Ye JC,Tak S,Han Y,Park HW

更新日期：2007-04-01 00:00:00

abstract：:A stereotaxic restraining assembly was designed and developed for simultaneous electrophysiological recordings and functional MRI (fMRI) data acquisition from a conscious rat. The design of the nonmagnetic stereotaxic apparatus facilitated the restraining of head and body of the unanesthetized conscious animal during ...

journal_title：Magnetic resonance in medicine

authors： Khubchandani M,Mallick HN,Jagannathan NR,Mohan Kumar V

更新日期：2003-05-01 00:00:00

abstract：:Measuring T(2) at 7.0 T is not trivial due to RF inhomogeneity effects, however, gradient echo sampling of a spin echo is insensitive to RF pulse errors, does not suffer from significant distortions, and allows T'(2) and T(2) to be estimated simultaneously. Gradient echo sampling of a spin echo results are relatively ...

journal_title：Magnetic resonance in medicine

authors： Cox EF,Gowland PA

更新日期：2010-11-01 00:00:00

abstract：:Multichannel transmission has the potential to improve many aspects of MRI through a new paradigm in excitation. In this study, multichannel transmission is used to address the effects that variations in B(0) homogeneity have on fat-saturation preparation through the use of the frequency, phase, and amplitude degrees ...

journal_title：Magnetic resonance in medicine

authors： Heilman JA,Derakhshan JD,Riffe MJ,Gudino N,Tkach J,Flask CA,Duerk JL,Griswold MA

更新日期：2012-08-01 00:00:00

abstract：:A new spherical navigator echo (SNAV) registration technique is presented. This technique starts by collecting a set of SNAV templates at a reference position. These templates are acquired by rotating the gradient system to result in rotation angles that uniformly cover a predefined range of rotation. The rotation ang...

journal_title：Magnetic resonance in medicine

authors： Liu J,Drangova M

更新日期：2011-02-01 00:00:00

abstract：PURPOSE:To develop an MRI acquisition and reconstruction framework for volumetric cine visualization of the fetal heart and great vessels in the presence of maternal and fetal motion. METHODS:Four-dimensional (4D) depiction was achieved using a highly-accelerated multi-planar real-time balanced steady-state free prece...

journal_title：Magnetic resonance in medicine

authors： van Amerom JFP,Lloyd DFA,Deprez M,Price AN,Malik SJ,Pushparajah K,van Poppel MPM,Rutherford MA,Razavi R,Hajnal JV

更新日期：2019-09-01 00:00:00

abstract：:A new model of compartmentalized relaxation--that which occurs for spins (protons) exchanging between compartments of different relaxation rates--is presented. This model generalizes previous ones by allowing spatially dependent relaxation within compartments. Solutions for the diffusion-Bloch equations are found via ...

journal_title：Magnetic resonance in medicine

authors： Barsky D,Pütz B,Schulten K

更新日期：1997-05-01 00:00:00

abstract：PURPOSE:To investigate four-dimensional flow denoising using the divergence-free wavelet (DFW) transform and compare its performance with existing techniques. THEORY AND METHODS:DFW is a vector-wavelet that provides a sparse representation of flow in a generally divergence-free field and can be used to enforce "soft" ...

journal_title：Magnetic resonance in medicine

authors： Ong F,Uecker M,Tariq U,Hsiao A,Alley MT,Vasanawala SS,Lustig M

更新日期：2015-02-01 00:00:00

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：:High-field (>or=3 T) cardiac MRI is challenged by inhomogeneities of both the static magnetic field (B(0)) and the transmit radiofrequency field (B(1)+). The inhomogeneous B fields not only demand improved shimming methods but also impede the correct determination of the zero-order terms, i.e., the local resonance fre...

journal_title：Magnetic resonance in medicine

authors： Schär M,Vonken EJ,Stuber M

更新日期：2010-02-01 00:00:00

abstract：:The most widely-used functional magnetic resonance imaging (fMRI) technique is based on the blood oxygenation level dependent (BOLD) effect, which requires at least partial uncoupling between cerebral blood flow (CBF) and oxygen consumption changes during increased mental activity. To compare BOLD and CBF effects duri...

journal_title：Magnetic resonance in medicine

authors： Kim SG,Uğurbil K

更新日期：1997-07-01 00:00:00

abstract：:Metallic particles have shaped the use of magnetic resonance imaging (MRI) for molecular and cellular imaging. Although these particles have generally been developed for extracellular residence, either as blood pool contrast agents or targeted contrast agents, the coopted use of these particles for intracellular label...

journal_title：Magnetic resonance in medicine

authors： Shapiro EM

更新日期：2015-01-01 00:00:00

abstract：:The authors introduce several sets of time-efficient gradient waveforms for applying isotropic diffusion weighting in NMR experiments. This creates signal attenuation that depends on the trace of the diffusion tensor and is therefore rotationally invariant. Numerical methods for the calculation of such gradient sets a...

journal_title：Magnetic resonance in medicine

authors： Wong EC,Cox RW,Song AW

更新日期：1995-08-01 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：:An intermolecular double-quantum coherence (iDQC) imaging technique was used to study auditory activation in the human brain at 1.5T with a dual temporal lobe surface phased array coil and a quadrature head coil. Preliminary results demonstrate that it is feasible to obtain auditory activation maps using iDQC imaging ...

journal_title：Magnetic resonance in medicine

authors： Zhong J,Kwok E,Chen Z

更新日期：2001-03-01 00:00:00

abstract：:MRI of myocardial perfusion observed with an extracellular contrast agent has proven valuable for the detection of coronary artery disease. During contrast enhancement transient dark rim artifacts are sometimes visible, complicating diagnosis and quantification. In this work a quantification of the frequency offsets c...

journal_title：Magnetic resonance in medicine

authors： Ferreira P,Gatehouse P,Bucciarelli-Ducci C,Wage R,Firmin D

更新日期：2008-10-01 00:00:00

abstract：:A localized proton 2D double-quantum (DQ) spin-echo spectroscopy technique was implemented on 1.5 T clinical MRI scanners for the detection of gamma-aminobutyrate (GABA) in the brain. The 2D approach facilitates separation of peaks overlapping with GABA in 1D DQ-filtered (DQF) spectra. This technique was applied to fo...

journal_title：Magnetic resonance in medicine

authors： Wang ZJ,Bergqvist C,Hunter JV,Jin D,Wang DJ,Wehrli S,Zimmerman RA

更新日期：2003-04-01 00:00:00

abstract：:Subject motion during brain magnetic resonance spectroscopy acquisitions generally reduces the magnetic field (B₀) homogeneity across the volume of interest or voxel. This is the case even if prospective motion correction ensures that the voxel follows the head. We introduce a novel method for rapidly mapping linear v...

journal_title：Magnetic resonance in medicine

authors： Keating B,Ernst T

更新日期：2012-11-01 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：:Stimulated-echo localized spectroscopy was combined with phase- and frequency-encoding gradients to obtain "zoom" or magnified images of specific organs in situ. The technique requires neither surface coils nor an imaging coil arrangement that exclusively isolates the target organ. This technique can be readily applie...

journal_title：Magnetic resonance in medicine

authors： Mills P,Chew W,Litt L,Moseley M

更新日期：1987-10-01 00:00:00

abstract：:High-quality, high-resolution, proton-decoupled natural-abundance 13C NMR spectra have been obtained in vitro at 100.6 MHz from unprocessed human pathology specimens of tumors and adjacent nonneoplastic control tissues from lung, colon, and prostate. In these preliminary studies, specific molecular parameters were ide...

journal_title：Magnetic resonance in medicine

authors： Halliday KR,Fenoglio-Preiser C,Sillerud LO

更新日期：1988-08-01 00:00:00

abstract：:A type of local coil (or surface coil) for magnetic resonance imaging and spectroscopy is described in which two circular loops of the same diameter are disposed axially with respect to each other and in which counter rotating currents (CRC) are supported in the two loops. This type of coil has been used for localized...

journal_title：Magnetic resonance in medicine

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

更新日期：1986-08-01 00:00:00

abstract：PURPOSE:To study the utility of fractional calculus in modeling gradient-recalled echo MRI signal decay in the normal human brain. METHODS:We solved analytically the extended time-fractional Bloch equations resulting in five model parameters, namely, the amplitude, relaxation rate, order of the time-fractional derivat...

journal_title：Magnetic resonance in medicine

authors： Qin S,Liu F,Turner IW,Yu Q,Yang Q,Vegh V

更新日期：2017-04-01 00:00:00

abstract：:Motion-sensitive phase contrast magnetic resonance imaging and magnetic resonance elastography are applied for the measurement of volumetric strain and tissue compressibility in human brain. Volumetric strain calculated by the divergence operator using a biphasic effective-medium model is related to dilatation and com...

journal_title：Magnetic resonance in medicine

authors： Hirsch S,Klatt D,Freimann F,Scheel M,Braun J,Sack I

更新日期：2013-09-01 00:00:00

abstract：PURPOSE:To assess the performance, in the presence of scanner instabilities, of three dynamic correction methods which integrate ∆B0 mapping into the chemical exchange saturation transfer (CEST) measurement and three established static ∆B0 -correction approaches. METHODS:A homogeneous phantom and five healthy voluntee...

journal_title：Magnetic resonance in medicine

authors： Poblador Rodriguez E,Moser P,Dymerska B,Robinson S,Schmitt B,van der Kouwe A,Gruber S,Trattnig S,Bogner W

更新日期：2019-08-01 00:00:00

abstract：:A novel ultra-rapid gradient echo (URGE) NMR imaging technique is introduced, which is capable of continuous high resolution 3D scanning while neither subject to fast gradient switching nor excessive RF power deposition. Sampling free induction decays instead of creating spin echoes enables maintaining a workable stea...

journal_title：Magnetic resonance in medicine

authors： Heid O,Deimling M,Huk WJ

更新日期：1995-01-01 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：:A new k-space direct matrix inversion (DMI) method is proposed here to accelerate non-Cartesian SENSE reconstructions. In this method a global k-space matrix equation is established on basic MRI principles, and the inverse of the global encoding matrix is found from a set of local matrix equations by taking advantage ...

journal_title：Magnetic resonance in medicine

authors： Qian Y,Zhang Z,Wang Y,Boada FE

更新日期：2006-08-01 00:00:00