Time-domain combination of MR spectroscopy data acquired using phased-array coils.

abstract：PURPOSE:To integrate markerless head motion tracking with prospectively corrected neuroanatomical MRI sequences and to investigate high-frequency motion correction during imaging echo trains. METHODS:A commercial 3D surface tracking system, which estimates head motion by registering point cloud reconstructions of the ...

journal_title：Magnetic resonance in medicine

authors： Frost R,Wighton P,Karahanoğlu FI,Robertson RL,Grant PE,Fischl B,Tisdall MD,van der Kouwe A

更新日期：2019-07-01 00:00:00

abstract：PURPOSE:Classification of pediatric brain tumors from 1 H-magnetic resonance spectroscopy (MRS) can aid diagnosis and management of brain tumors. However, varied incidence of the different tumor types leads to imbalanced class sizes and introduces difficulties in classifying rare tumor groups. This study assessed diffe...

journal_title：Magnetic resonance in medicine

authors： Zarinabad N,Wilson M,Gill SK,Manias KA,Davies NP,Peet AC

更新日期：2017-06-01 00:00:00

abstract：:In this work a model-free arterial spin labeling (ASL) quantification approach for measuring cerebral blood flow (CBF) and arterial blood volume (aBV) is proposed. The method is based on the acquisition of a train of multiple images following the labeling scheme. Perfusion is obtained using deconvolution in a manner s...

journal_title：Magnetic resonance in medicine

authors： Petersen ET,Lim T,Golay X

更新日期：2006-02-01 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 orientation dependence of the free induction decay (FID) of 1H NMR water signal in ex vivo bovine digital flexor tendon at the native level of hydration is reported. Residual dipolar coupling due to the overall tissue anisotropy produces a 6:1 change in the signal intensity as an angle between the long axis of a s...

journal_title：Magnetic resonance in medicine

authors： Krasnosselskaia LV,Fullerton GD,Dodd SJ,Cameron IL

更新日期：2005-08-01 00:00:00

abstract：PURPOSE:Sensitivity encoding (SENSE) reconstruction of multiband echo planar imaging (EPI) may cause artifacts when simultaneously excited slices require different phase correction to remove the EPI-specific ghost shifted by half of the matrix size (N). We propose a simplified solution of this problem that combines SEN...

journal_title：Magnetic resonance in medicine

authors： Hennel F,Buehrer M,von Deuster C,Seuven A,Pruessmann KP

更新日期：2016-09-01 00:00:00

abstract：:Human cardiac 31P nuclear magnetic resonance (NMR) spectra are usually quantified in relative terms, i.e., the ratio of metabolite signals is calculated. If 31P NMR spectroscopy of the heart is to emerge as a clinically relevant diagnostic modality, reliable quantification of absolute concentrations of 31P metabolites...

journal_title：Magnetic resonance in medicine

authors： Meininger M,Landschütz W,Beer M,Seyfarth T,Horn M,Pabst T,Haase A,Hahn D,Neubauer S,von Kienlin M

更新日期：1999-04-01 00:00:00

abstract：:Lower extremity peripheral vein bypass grafts (LE-PVBG) imaged with high-resolution black blood three-dimensional (3D) inner-volume (IV) fast spin echo (FSE) MRI at 1.5 Tesla possess a two-layer appearance in T1W images while only the inner layer appears visible in the corresponding T2W images. This study quantifies t...

journal_title：Magnetic resonance in medicine

authors： Mitsouras D,Owens CD,Conte MS,Ersoy H,Creager MA,Rybicki FJ,Mulkern RV

更新日期：2009-09-01 00:00:00

abstract：:This study investigated the use of dynamic, volumetric MRI to measure 3D skeletal motion. Ten healthy subjects were positioned on a MR-compatible knee loading device and instructed to harmonically flex and extend their knee at 0.5 Hz. The device induced active quadriceps loading with knee flexion, similar to the load ...

journal_title：Magnetic resonance in medicine

authors： Kaiser J,Bradford R,Johnson K,Wieben O,Thelen DG

更新日期：2013-05-01 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：: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：:A new fully automatic algorithm for the segmentation of the brain and total intracranial cerebrospinal fluid (CSF) from T(1)-weighted volume MRI scans of the head, called Exbrain v.2, is described. The algorithm was developed in the context of serial intracranial volumetry. A brain mask obtained using a previous versi...

journal_title：Magnetic resonance in medicine

authors： Lemieux L,Hammers A,Mackinnon T,Liu RS

更新日期：2003-05-01 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：: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：PURPOSE:To develop a rapid and motion-robust technique for volumetric MRI, which is based on cross-sectional real-time MRI acquisitions with automatic advancement of the slice position. METHODS:Real-time MRI with a frame-by-frame moving cross-section is performed with use of highly undersampled radial gradient-echo se...

journal_title：Magnetic resonance in medicine

authors： Voit D,Kalentev O,van Zalk M,Joseph AA,Frahm J

更新日期：2020-05-01 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

abstract：:For protons diffusing among a system of magnetic particles, the process by which initial phase coherence is lost depends substantially on particle size. In this article, evidence for three dephasing mechanisms is presented: an incremental process at small particle sizes (motional averaging regime), a discrete process ...

journal_title：Magnetic resonance in medicine

authors： de Haan HW

更新日期：2011-12-01 00:00:00

abstract：PURPOSE:To develop and evaluate a neural network-based method for Gibbs artifact and noise removal. METHODS:A convolutional neural network (CNN) was designed for artifact removal in diffusion-weighted imaging data. Two implementations were considered: one for magnitude images and one for complex images. Both models we...

journal_title：Magnetic resonance in medicine

authors： Muckley MJ,Ades-Aron B,Papaioannou A,Lemberskiy G,Solomon E,Lui YW,Sodickson DK,Fieremans E,Novikov DS,Knoll F

更新日期：2021-01-01 00:00:00

abstract：:MRI after a constant infusion (CI) of Gd-DTPA has been used to identify the extent of myocardial infarction (MI). However, Gd-DTPA-enhanced "viability" imaging is more commonly performed with a bolus (for "delayed-enhancement" (DE) imaging). This study sought to determine how image delay time and time postinfarction i...

journal_title：Magnetic resonance in medicine

authors： Thornhill RE,Prato FS,Wisenberg G,Moran GR,Sykes J

更新日期：2004-11-01 00:00:00

abstract：:A modified Prony method (MPM) was applied to analyze the main signals present in spatially resolved 31P NMR spectra of MCF7 breast tumors implanted in nude mice. First, the method was tested on synthetic data to establish its limits of reliability. Its performance with respect to peak identification and quantification...

journal_title：Magnetic resonance in medicine

authors： Viti V,Ragona R,Guidoni L,Barone P,Furman E,Degani H

更新日期：1997-08-01 00:00:00

abstract：PURPOSE:Delta relaxation enhanced magnetic resonance (dreMR) imaging requires an auxiliary B0 electromagnet capable of shifting the main magnetic field within a clinical 1.5 Tesla (T) MR system. In this work, the main causes of interaction between an actively shielded, insertable resistive B0 electromagnet and a 1.5T s...

journal_title：Magnetic resonance in medicine

authors： Harris CT,Handler WB,Araya Y,Martínez-Santiesteban F,Alford JK,Dalrymple B,Van Sas F,Chronik BA,Scholl TJ

更新日期：2014-10-01 00:00:00

abstract：:Proton MRS (1 H MRS) provides noninvasive, quantitative metabolite profiles of tissue and has been shown to aid the clinical management of several brain diseases. Although most modern clinical MR scanners support MRS capabilities, routine use is largely restricted to specialized centers with good access to MR research...

journal_title：Magnetic resonance in medicine

authors： Wilson M,Andronesi O,Barker PB,Bartha R,Bizzi A,Bolan PJ,Brindle KM,Choi IY,Cudalbu C,Dydak U,Emir UE,Gonzalez RG,Gruber S,Gruetter R,Gupta RK,Heerschap A,Henning A,Hetherington HP,Huppi PS,Hurd RE,Kantarci K,Ka

更新日期：2019-08-01 00:00:00

abstract：:In this study, the precision and accuracy of a new method for measuring axial rotations of the lumbar vertebrae, which are thought to be increased in patients with degenerative spinal instability, were estimated. A standard image registration algorithm involving a user-selected center of rotation was adapted for this ...

journal_title：Magnetic resonance in medicine

authors： Rogers BP,Haughton VM,Arfanakis K,Meyerand ME

更新日期：2002-12-01 00:00:00

abstract：:Manipulation of the data describing two-dimensional magnetic resonance (MR) images can be used to zoom an image, decrease image noise and artifacts by modeling, or emphasize object edges in the field of view. In this paper, a two-dimensional band-selectable digital filtering (2D-BSDF) technique is detailed. This can b...

journal_title：Magnetic resonance in medicine

authors： Mitchell DK,Nichols ST,Smith MR,Scott K

更新日期：1989-03-01 00:00:00

abstract：PURPOSE:To develop a novel analytical method for quantification of chemical exchange saturation transfer (CEST) in the transient state. The proposed method aims to reduce the effects of non-chemical-exchange (non-CE) parameters on the CEST signal, emphasizing the effect of chemical exchange. METHODS:The difference in ...

journal_title：Magnetic resonance in medicine

authors： Wang Y,Zhang Y,Zhao X,Wu B,Gao JH

更新日期：2017-11-01 00:00:00

abstract：:Acute normovolemic hemodilution (HD) was induced in anesthetized rats to assess the effect of changes in hematocrit (Hct) on signal intensity in T2*-weighted magnetic resonance (MR) images. Other relevant physiological parameters were maintained invariant. Two degrees of HD were induced: mild (Hct reduced from 42.6+/-...

journal_title：Magnetic resonance in medicine

authors： Lin W,Paczynski RP,Celik A,Hsu CY,Powers WJ

更新日期：1998-12-01 00:00:00

abstract：:The purpose of this study was to demonstrate the feasibility of dynamic oxygen-enhanced MRI in a clinical setting. We hypothesized that dynamic oxygen enhancement can reflect the regional diffusing capacity of the lung. Ten patients with pulmonary emphysema and seven healthy volunteers were examined with a respiratory...

journal_title：Magnetic resonance in medicine

authors： Ohno Y,Hatabu H,Takenaka D,Van Cauteren M,Fujii M,Sugimura K

更新日期：2002-06-01 00:00:00

abstract：:Chemical shifts were extracted from in vivo 3-dimensional 31P NMR CSI data and pH images were constructed. The images could spatially resolve tissue pH ranging from 5.8 to 7.2 (with uncertainty of 0.11-0.17 pH unit) in an ischemia-reperfusion model of diabetic rat calf muscles. ...

journal_title：Magnetic resonance in medicine

authors： Morikawa S,Inubushi T,Kito K,Kido C

更新日期：1993-02-01 00:00:00

abstract：:Keyhole acquisition techniques have been used to reduce image acquisition times primarily in contrast agent studies and via simulation in interventional MRI procedures. More recent simulations have suggested that improved definition of an interventional device [e.g., biopsy needles, radio frequency (RF) electrodes] co...

journal_title：Magnetic resonance in medicine

authors： Hwang KP,Lim J,Wendt M,Merkle E,Lewin JS,Duerk JL

更新日期：1999-09-01 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