Prospective real-time head motion correction using inductively coupled wireless NMR probes.

abstract：PURPOSE:High-resolution three-dimensional (3D) structural MRI is useful for delineating complex or small structures of the body. However, it requires long acquisition times and high SAR, limiting its clinical use. The purpose of this work is to accelerate the acquisition of high-resolution images by combining compresse...

journal_title：Magnetic resonance in medicine

authors： Cristobal-Huerta A,Poot DHJ,Vogel MW,Krestin GP,Hernandez-Tamames JA

更新日期：2019-09-01 00:00:00

abstract：:High-signal artifacts produced by cerebrospinal fluid (CSF) flow can adversely affect fluid-attenuated inversion recovery (FLAIR) imaging of the brain and spinal cord. This study explores the use of a nonslice-selective inversion pulse to eliminate CSF flow artifacts together with a technique called "K-space Reordered...

journal_title：Magnetic resonance in medicine

authors： Herlihy AH,Oatridge A,Curati WL,Puri BK,Bydder GM,Hajnal JV

更新日期：2001-08-01 00:00:00

abstract：:The application of spectroscopy techniques to the study of normal and pathological tissue is currently limited by the difficulties of acquiring precisely localized spectra and analyzing the resulting, relatively low signal-to-noise data. Interpretation of multivoxel spectroscopy data is greatly facilitated by estimati...

journal_title：Magnetic resonance in medicine

authors： Nelson SJ,Vigneron DB,Brown TR

更新日期：1992-05-01 00:00:00

abstract：:Certain kinds of artifacts have been reported when projection reconstruction (PR) techniques are used in magnetic resonance imaging (MRI). These will occur if the spacing between samples in k-space is too large. It has been suggested that PR requires finer k-space sampling than does two-dimensional Fourier reconstruct...

journal_title：Magnetic resonance in medicine

authors： Joseph PM

更新日期：1998-09-01 00:00:00

abstract：PURPOSE:Applications of dynamic shimming require high field fidelity, and characterizing the shim field dynamics is therefore necessary. Modeling the system as linear and time-invariant, the purpose of this work was to measure the impulse response function with optimal sensitivity. THEORY AND METHODS:Frequency-swept p...

journal_title：Magnetic resonance in medicine

authors： Vannesjo SJ,Dietrich BE,Pavan M,Brunner DO,Wilm BJ,Barmet C,Pruessmann KP

更新日期：2014-08-01 00:00:00

abstract：:A new method for efficiently processing MRS data acquired with phased-array coils is presented. The method consists of performing phase compensation (i.e., redefining the signal phase relative to a common reference) of the signals in the time domain prior to combining the signals. The resulting spectra are equivalent ...

journal_title：Magnetic resonance in medicine

authors： Brown MA

更新日期：2004-11-01 00:00:00

abstract：:Echo-planar spectroscopic imaging (EPSI) can be used for fast spectroscopic imaging of water and fat resonances at high resolution to improve structural and functional imaging. Because of the use of oscillating gradients during the free induction decay (FID), spectra obtained with EPSI are often degraded by Nyquist gh...

journal_title：Magnetic resonance in medicine

authors： Du W,Du YP,Fan X,Zamora MA,Karczmar GS

更新日期：2003-06-01 00:00:00

abstract：:We applied MRI to the in vivo detection of spontaneous colorectal tumors in a unique mouse model, the Fox Chase Cancer Center (FCCC) ApcMIN mouse. Unlike other Min (multiple intestinal neoplasia) strains, FCCC ApcMIN animals develop an appreciable number of tumors in the large intestine, which makes them an appropriat...

journal_title：Magnetic resonance in medicine

authors： Hensley HH,Chang WC,Clapper ML

更新日期：2004-09-01 00:00:00

abstract：:Parallel imaging reconstructions result in spatially varying noise amplification characterized by the g-factor, precluding conventional measurements of noise from the final image. A simple Monte Carlo based method is proposed for all linear image reconstruction algorithms, which allows measurement of signal-to-noise r...

journal_title：Magnetic resonance in medicine

authors： Robson PM,Grant AK,Madhuranthakam AJ,Lattanzi R,Sodickson DK,McKenzie CA

更新日期：2008-10-01 00:00:00

abstract：PURPOSE:To enable highly accelerated distortion-free MRI near metal by separating on- and off-resonance to exploit the redundancy of slice-phase encoding for the dominant on-resonance component. METHODS:Multispectral MRI techniques resolve off-resonance distortions by a combination of limited excitation bins and addit...

journal_title：Magnetic resonance in medicine

authors： Levine E,Stevens K,Beaulieu C,Hargreaves B

更新日期：2018-03-01 00:00:00

abstract：PURPOSE:To enable accurate magnetic resonance (MR) parameter mapping with accelerated data acquisition, utilizing recent advances in constrained imaging with sparse sampling. THEORY AND METHODS:A new constrained reconstruction method based on low-rank and sparsity constraints is proposed to accelerate MR parameter map...

journal_title：Magnetic resonance in medicine

authors： Zhao B,Lu W,Hitchens TK,Lam F,Ho C,Liang ZP

更新日期：2015-08-01 00:00:00

abstract：:The investigation of flow behavior in coronary arteries is of great importance for an understanding of heart failure and heart regulation mechanisms. The purpose of the present study was to demonstrate that flow velocity can be quantified in the coronary arteries of the isolated rat heart with high-resolution phase co...

journal_title：Magnetic resonance in medicine

authors： Köhler S,Hiller KH,Jakob PM,Bauer WR,Haase A

更新日期：2003-09-01 00:00:00

abstract：:Nonlinear feedback interactions have been shown to amplify contrast due to small differences in resonance frequency arising from microscopic susceptibility variations. Determining whether the selectivity of feedback-based contrast enhancement for small resonance frequency variations remains valid even in the presence ...

journal_title：Magnetic resonance in medicine

authors： Huang SY,Yang SS,Lin YY

更新日期：2009-04-01 00:00:00

abstract：:This study determines the accuracy and feasibility of using localized spin-lattice (T1) relaxation time measurements from magnetic resonance (MR) images to follow changes in extracellular/intracellular fluid ratios in defined subvolumes of living tissue. A red blood cell suspension was used as a test system and a simp...

journal_title：Magnetic resonance in medicine

authors： Martin MA,Tatton WG,Lemaire C,Armstrong RL

更新日期：1990-07-01 00:00:00

abstract：:Spin-echo images of 10 myocardial infarcts in nine mini-pigs were obtained at 30 h, 3 days, and approximately 10 days postinfarction. Infarcts were not detected at all at 30 h in five out of five cases examined. At 3 days postembolization (six cases) one infarct was certainly detected, whilst at 10 days (nine cases) a...

journal_title：Magnetic resonance in medicine

authors： Checkley D,Loveday BE,Waterton JC,Zhu XP,Isherwood I

更新日期：1987-09-01 00:00:00

abstract：:Parameter-selective imaging for tissue characterization is performed at low magnetic fields (0.24-0.28 T) employing echo trains with a large number of echoes (less than or equal to 50), high-power pulses, and the projection reconstruction method. Preprocessing of the raw echoes is important for the quality of the echo...

journal_title：Magnetic resonance in medicine

authors： Staemmler M,Gersonde K

更新日期：1986-06-01 00:00:00

abstract：PURPOSE:To develop and evaluate a novel 2D phase-unwrapping method that works robustly in the presence of severe noise, rapid phase changes, and disconnected regions. THEORY AND METHODS:The MR phase map usually varies rapidly in regions adjacent to wraps. In contrast, the phasors can vary slowly, especially in regions...

journal_title：Magnetic resonance in medicine

authors： Cheng J,Mei Y,Liu B,Guan J,Liu X,Wu EX,Feng Q,Chen W,Feng Y

更新日期：2018-01-01 00:00:00

abstract：:Patient-specific radiofrequency shimming in high-field MRI strengthens the need for online, patient-specific specific absorption rate (SAR) monitoring. Numerical simulation is currently most effective for this purpose but may require a patient-specific dielectric model. To investigate whether a generic model may be co...

journal_title：Magnetic resonance in medicine

authors： de Greef M,Ipek O,Raaijmakers AJ,Crezee J,van den Berg CA

更新日期：2013-05-01 00:00:00

abstract：PURPOSE:The goal of this work was to detect disease-related microstructural changes to the liver using magnetic resonance imaging. Chronic liver disease can cause microstructural changes in the liver that reduce plasma access to the perisinusoidal space--the site of exchange between the blood plasma and the hepatic par...

journal_title：Magnetic resonance in medicine

authors： Beeman SC,Mandarino LJ,Georges JF,Bennett KM

更新日期：2013-12-01 00:00:00

abstract：PURPOSE:Structure-guided total variation is a recently introduced prior that allows reconstruction of images using knowledge of the location and orientation of edges in a reference image. In this work, we demonstrate the advantages of a variant of structure-guided total variation known as directional total variation (D...

journal_title：Magnetic resonance in medicine

authors： Teh I,McClymont D,Carruth E,Omens J,McCulloch A,Schneider JE

更新日期：2020-10-01 00:00:00

abstract：:The course of pulmonary edema formation after an intratracheal (i.t.) instillation of ovalbumin was followed noninvasively by magnetic resonance imaging (MRI) in actively sensitized Brown Norway (BN) rats. Changes in edema volume assessed by MRI mimicked the results from the analysis of the number and activation of in...

journal_title：Magnetic resonance in medicine

authors： Beckmann N,Tigani B,Ekatodramis D,Borer R,Mazzoni L,Fozard JR

更新日期：2001-01-01 00:00:00

abstract：:Echo-planar imaging (EPI) is the standard technique for dynamic susceptibility-contrast (DSC) perfusion MRI. However, EPI suffers from well-known geometric distortions, which can be reduced by increasing the k-space phase velocity. Moreover, the long echo times (TEs) used in DSC lead to signal saturation of the arteri...

journal_title：Magnetic resonance in medicine

authors： Newbould RD,Skare ST,Jochimsen TH,Alley MT,Moseley ME,Albers GW,Bammer R

更新日期：2007-07-01 00:00:00

abstract：:Parallel magnetic resonance imaging (pMRI) using multichannel receiver coils has emerged as an effective tool to reduce imaging time in various applications. However, the issue of accurate estimation of coil sensitivities has not been fully addressed, which limits the level of speed enhancement achievable with the tec...

journal_title：Magnetic resonance in medicine

authors： Ying L,Sheng J

更新日期：2007-06-01 00:00:00

abstract：:In the present work, diffusion-weighted (DW)-NMR spectroscopy of glutamate was performed during a (13)C-labeled glucose infusion in monkey brain (six experiments). It is shown that glutamate (13)C labeling occurs significantly faster at higher diffusion weightings-slightly for glutamate in position C4, and more marked...

journal_title：Magnetic resonance in medicine

authors： Valette J,Chaumeil M,Guillermier M,Bloch G,Hantraye P,Lebon V

更新日期：2008-08-01 00:00:00

abstract：:Phase-contrast MRI can provide high-resolution angiographic velocity images, especially in conjunction with non-Cartesian k-space sampling. However, acquisitions can be sensitive to errors from artifacts from main magnetic field inhomogeneities and chemical shift from fat. Particularly in body imaging, fat content can...

journal_title：Magnetic resonance in medicine

authors： Johnson KM,Wieben O,Samsonov AA

更新日期：2010-06-01 00:00:00

abstract：PURPOSE:Multi-slice radiofrequency (RF) pulses have higher specific absorption rates, more peak RF power, and longer pulse durations than single-slice RF pulses. Gradient field design techniques using a z-gradient array are investigated for exciting multiple slices with a single-band RF pulse. THEORY AND METHODS:Two d...

journal_title：Magnetic resonance in medicine

authors： Ertan K,Taraghinia S,Sadeghi A,Atalar E

更新日期：2018-07-01 00:00:00

abstract：PURPOSE:Diabetic nephropathy (DN) is the leading cause of renal failure; however, current clinical tests are insufficient for assessing this disease. DN is associated with changes in renal metabolites, so we evaluated the utility of chemical exchange saturation transfer (CEST) imaging to detect changes characteristic o...

journal_title：Magnetic resonance in medicine

authors： Wang F,Kopylov D,Zu Z,Takahashi K,Wang S,Quarles CC,Gore JC,Harris RC,Takahashi T

更新日期：2016-11-01 00:00:00

abstract：:NMR relaxation times (T1 and T2) and the water content (WC) of in vitro rat lungs were measured during the course of endotoxin lung injury in rats. Measurements of normal lungs, untreated endotoxin-injured lungs, and endotoxin-injured lungs treated with methylprednisolone (MPSL) were compared. The untreated endotoxin ...

journal_title：Magnetic resonance in medicine

authors： Shioya S,Haida M,Tsuji C,Ono Y,Miyairi A,Fukuzaki M,Ohta Y,Yamabayashi H

更新日期：1990-08-01 00:00:00

abstract：PURPOSE:Recent MRI studies have suggested that the magnetic susceptibility of white matter (WM) in the human brain is anisotropic, providing a new contrast mechanism for the visualization of fiber bundles and allowing the extraction of cellular compartment-specific information. This study provides an independent confir...

journal_title：Magnetic resonance in medicine

authors： van Gelderen P,Mandelkow H,de Zwart JA,Duyn JH

更新日期：2015-11-01 00:00:00

abstract：PURPOSE:To develop a new parallel transmit (pTx) pulse design for simultaneous multiband (MB) excitation in order to tackle simultaneously the problems of transmit B1 (B1+) inhomogeneity and total radiofrequency (RF) power, so as to allow for optimal RF excitation when using MB pulses for slice acceleration for high an...

journal_title：Magnetic resonance in medicine

authors： Wu X,Schmitter S,Auerbach EJ,Moeller S,Uğurbil K,Van de Moortele PF

更新日期：2013-09-01 00:00:00