Gradient field switching as a source for artifacts in MR imaging of metallic stents.

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：:Since its inception, functional magnetic resonance imaging (fMRI) has seen rapid progress in the application to neuroscience. Common gradient-recalled acquisition methods are susceptible to static field inhomogeneities, resulting in signal loss at the medial temporal area important for memory function or at the basal ...

journal_title：Magnetic resonance in medicine

authors： Song AW,Mao H,Muthupillai R,Haist F,Dixon WT

更新日期：1999-10-01 00:00:00

abstract：:Magnetic resonance (MR) can offer a unique window on the structure/function relationships in the brain, by utilizing the established link between tissue function, metabolism, and hemodynamics. This report focuses on recent applications of MR-based cerebral blood volume (CBV) imaging in humans. Our methodology uses hig...

journal_title：Magnetic resonance in medicine

authors： Rosen BR,Belliveau JW,Aronen HJ,Kennedy D,Buchbinder BR,Fischman A,Gruber M,Glas J,Weisskoff RM,Cohen MS

更新日期：1991-12-01 00:00:00

abstract：:Proton magnetic resonance spectroscopy ((1)H MRS) was used to determine brain temperature in healthy volunteers. Partially water-suppressed (1)H MRS data sets were acquired at 3T from four different gray matter (GM)/white matter (WM) volumes. Brain temperatures were determined from the chemical-shift difference betwee...

journal_title：Magnetic resonance in medicine

authors： Childs C,Hiltunen Y,Vidyasagar R,Kauppinen RA

更新日期：2007-01-01 00:00:00

abstract：:MRI using hyperpolarized (13) C-labeled pyruvate is a promising tool to biochemically profile tumors and monitor their response to therapy. This technique requires injection of pyruvate into tumor-bearing animals. Pyruvate is an endogenous entity but the influence of exogenously injected bolus doses of pyruvate on tum...

journal_title：Magnetic resonance in medicine

authors： Saito K,Matsumoto S,Devasahayam N,Subramanian S,Munasinghe JP,Morris HD,Lizak MJ,Ardenkjaer-Larsen JH,Mitchell JB,Krishna MC

更新日期：2012-03-01 00:00:00

abstract：PURPOSE:To evaluate convex gradient optimization (CVX) for increased spatiotemporal resolution and improved accuracy for phase-contrast MRI (PC-MRI). METHODS:A conventional flow-compensated and flow-encoded (FCFE) PC-MRI sequence was compared with a CVX PC-MRI sequence using numerical simulations, flow phantom experim...

journal_title：Magnetic resonance in medicine

authors： Middione MJ,Wu HH,Ennis DB

更新日期：2014-12-01 00:00:00

abstract：PURPOSE:To examine the detection sensitivity for the rapidly exchanging hydroxyl protons of D-glucose using the recently developed on-resonance variable delay multi-pulse (onVDMP) chemical exchange saturation transfer (CEST) technique. METHODS:The onVDMP method was applied for the detection of water signal changes upo...

journal_title：Magnetic resonance in medicine

authors： Xu X,Xu J,Chan KWY,Liu J,Liu H,Li Y,Chen L,Liu G,van Zijl PCM

更新日期：2019-01-01 00:00:00

abstract：PURPOSE:To develop and evaluate a novel two-dimensional self-gated imaging technique for free-breathing cardiac cine MRI that is free of motion-detection overhead and requires minimal planning for motion tracking. METHODS:Motion along the readout direction was extracted solely from normal Cartesian imaging readouts ne...

journal_title：Magnetic resonance in medicine

authors： Guo L,Derbyshire JA,Herzka DA

更新日期：2016-08-01 00:00:00

abstract：:Pulsed arterial spin labeling (ASL) techniques provide a noninvasive method of obtaining qualitative and quantitative perfusion images with MRI. ASL techniques employ inversion recovery and/or saturation recovery to induce perfusion weighting, and thus the performance of these techniques is dependent on the slice prof...

journal_title：Magnetic resonance in medicine

authors： Keilholz-George SD,Knight-Scott J,Berr SS

更新日期：2001-07-01 00:00:00

abstract：:To quantify metabolite and cation concentrations using NMR spectroscopy, the volumes of intracellular and extracellular spaces must be known. We describe a simple 31P NMR spectroscopic method that employs dimethyl methylphosphonate (DMMP) as a marker of total water space and phenylphosphonate (PPA) as a marker of extr...

journal_title：Magnetic resonance in medicine

authors： Clarke K,Anderson RE,Nédélec JF,Foster DO,Ally A

更新日期：1994-08-01 00:00:00

abstract：:One-dimensional spectroscopic imaging of (13)C-4-glutamate turnover is performed in the human brain with a 6 cc nominal voxel resolution at 4T. Data were acquired with an indirect detection approach using a short spin echo single quantum (1)H-(13)C heteronuclear editing method and a 7 cm surface coil with quadrature (...

journal_title：Magnetic resonance in medicine

authors： Pan JW,Stein DT,Telang F,Lee JH,Shen J,Brown P,Cline G,Mason GF,Shulman GI,Rothman DL,Hetherington HP

更新日期：2000-11-01 00:00:00

abstract：PURPOSE:A ghost correction strategy for Simultaneous Multi-Slice (SMS) EPI methods that provides improved ghosting artifact reduction compared to conventional methods is presented. Conventional Nyquist ghost correction methods for SMS-EPI rely on navigator data that contain phase errors from all slices in the simultane...

journal_title：Magnetic resonance in medicine

authors： Hoge WS,Setsompop K,Polimeni JR

更新日期：2018-10-01 00:00:00

abstract：:Orientational anisotropy of T2 and T1 relaxation times, diffusion, and magnetization transfer has been investigated for six different tissues: tendon, cartilage, kidney, muscle, white matter, and optic nerve. Relaxation anisotropy was observed for tendon and cartilage, and diffusional anisotropy was measured in kidney...

journal_title：Magnetic resonance in medicine

authors： Henkelman RM,Stanisz GJ,Kim JK,Bronskill MJ

更新日期：1994-11-01 00:00:00

abstract：:A novel center-out 3D trajectory for sampling magnetic resonance data is presented. The trajectory set is based on a single Fermat spiral waveform, which is substantially undersampled in the center of k-space. Multiple trajectories are combined in a "stacked cone" configuration to give very uniform sampling throughout...

journal_title：Magnetic resonance in medicine

authors： Pipe JG,Zwart NR,Aboussouan EA,Robison RK,Devaraj A,Johnson KO

更新日期：2011-11-01 00:00:00

abstract：PURPOSE:To develop and evaluate a technique for accelerating phase contrast MRI (PC-MRI) acquisitions without significant compromise in flow quantification accuracy. METHODS:PC-MRI is commonly acquired using interleaved flow-compensated (FC) and flow-encoded (FE) echoes. We hypothesized that FC data, which represent b...

journal_title：Magnetic resonance in medicine

authors： Wang D,Shao J,Rapacchi S,Middione MJ,Ennis DB,Hu P

更新日期：2015-02-01 00:00:00

abstract：PURPOSE:To improve signal-to-noise ratio (SNR) for high-resolution spectroscopic imaging using a subspace-based technique known as SPectroscopic Imaging by exploiting spatiospectral CorrElation (SPICE). METHODS:The proposed method is based on a union-of-subspaces model of MRSI signals, which exploits the partial separ...

journal_title：Magnetic resonance in medicine

authors： Ma C,Lam F,Ning Q,Johnson CL,Liang ZP

更新日期：2017-02-01 00:00:00

abstract：PURPOSE:Quantitative myocardial perfusion mapping has advantages over qualitative assessment, including the ability to detect global flow reduction. However, it is not clinically available and remains a research tool. Building upon the previously described imaging sequence, this study presents algorithm and implementat...

journal_title：Magnetic resonance in medicine

authors： Xue H,Brown LAE,Nielles-Vallespin S,Plein S,Kellman P

更新日期：2020-02-01 00:00:00

abstract：:Due to the presence of gross magnetic susceptibility artifacts, functional MRI (fMRI) has proved problematic in studies of the human inferior frontal cortex (IFC). There is a strong desire, therefore, to employ techniques that mitigate susceptibility artifacts in the IFC while preserving the imaging parameters of an f...

journal_title：Magnetic resonance in medicine

authors： Wilson JL,Jezzard P

更新日期：2003-11-01 00:00:00

abstract：:Artery wall motion and strain play important roles in vascular remodeling and may be important in the pathogenesis of vascular disease. In vivo observations of circumferentially nonuniform wall motion in the human aorta suggest that nonuniform strain may contribute to the localization of vascular pathology. A velocity...

journal_title：Magnetic resonance in medicine

authors： Draney MT,Arko FR,Alley MT,Markl M,Herfkens RJ,Pelc NJ,Zarins CK,Taylor CA

更新日期：2004-08-01 00:00:00

abstract：:Electron paramagnetic resonance imaging using nitroxides is a powerful method for visualizing the redox status modulated by oxidative stress in vivo. Typically, however, data acquisition times have been too slow to obtain a sufficient number of projections for three-dimensional images, when using continuous wave-elect...

journal_title：Magnetic resonance in medicine

authors： Fujii H,Sato-Akaba H,Kawanishi K,Hirata H

更新日期：2011-01-01 00:00:00

abstract：:Golgi impregnation is unique in its ability to display the dendritic trees and axons of large numbers of individual neurons by histology. Here we apply magnetic resonance microscopy to visualize the neuroanatomy of animal models by combining histologic fixation chemistry with paramagnetic contrast agents. Although the...

journal_title：Magnetic resonance in medicine

authors： Zhang X,Bearer EL,Perles-Barbacaru AT,Jacobs RE

更新日期：2010-05-01 00:00:00

abstract：PURPOSE:Acquisition of high-resolution imaging data using multiple excitations without the sensitivity to fluctuations of the transverse magnetization phase, which is a major problem of multi-shot MRI. THEORY AND METHODS:The concept of superresolution MRI based on microscopic tagging is analyzed using an analogy with ...

journal_title：Magnetic resonance in medicine

authors： Hennel F,Tian R,Engel M,Pruessmann KP

更新日期：2018-12-01 00:00:00

abstract：PURPOSE:The correlation between glutamine metabolism and oncogene expression in cancers has led to a renewed interest in the role of glutamine in cancer cell survival. Hyperpolarized [5-(13) C]glutamine is evaluated as a potential biomarker for noninvasive metabolic measurements of drug response in prostate cancer cell...

journal_title：Magnetic resonance in medicine

authors： Canapè C,Catanzaro G,Terreno E,Karlsson M,Lerche MH,Jensen PR

更新日期：2015-06-01 00:00:00

abstract：:Magnetic resonance imaging allows numerous k-space sampling schemes such as cartesian, polar, spherical, and other non-rectilinear trajectories. Non-rectilinear MR acquisitions permit fast scan times and can suppress motion artifacts. Still, these sampling schemes may adversely affect the image characteristics due to ...

journal_title：Magnetic resonance in medicine

authors： Lauzon ML,Rutt BK

更新日期：1996-12-01 00:00:00

abstract：:Accelerated magnetic resonance imaging techniques reduce signal acquisition time by undersampling k-space. A fundamental problem in accelerated magnetic resonance imaging is the recovery of quality images from undersampled k-space data. Current state-of-the-art recovery algorithms exploit the spatial and temporal stru...

journal_title：Magnetic resonance in medicine

authors： Asif MS,Hamilton L,Brummer M,Romberg J

更新日期：2013-09-01 00:00:00

abstract：:The absolute partial pressure of oxygen (pO(2)) in the mammary gland pad and femoral muscle of female mice was measured using EPR oximetry at 700 MHz. A small quantity of lithium phthalocyanine (LiPc) crystals was implanted in both mammary and femoral muscle tissue of female C3H mice. Subsequent EPR measurements were ...

journal_title：Magnetic resonance in medicine

authors： Matsumoto A,Matsumoto S,Sowers AL,Koscielniak JW,Trigg NJ,Kuppusamy P,Mitchell JB,Subramanian S,Krishna MC,Matsumoto K

更新日期：2005-12-01 00:00:00

abstract：PURPOSE:Because of short signal lifetimes and respiratory motion, 3D lung MRI is still challenging today. Zero-TE (ZTE) pulse sequences offer promising solutions as they overcome the issue of short T 2 ∗ ...

journal_title：Magnetic resonance in medicine

authors： Boucneau T,Fernandez B,Besson FL,Menini A,Wiesinger F,Durand E,Caramella C,Darrasse L,Maître X

更新日期：2021-02-01 00:00:00

abstract：:The equal-phase line (EPL) algorithm is proposed as a means of allowing rapid Fourier transform (FT) reconstruction of MR image data acquired on a non-Cartesian grid. The pixels on the image are grouped according to their positions. The pixels in a group have the same phase in the complex exponential function -exp[j2p...

journal_title：Magnetic resonance in medicine

authors： Qian Y,Lin J,Jin D

更新日期：2002-06-01 00:00:00

abstract：PURPOSE:Quantitative susceptibility map (QSM) reconstruction is ill posed due to the zero values on the "magic angle cone" that make the maps prone to streaking artifacts. We propose projection onto convex sets (POCS) in the method of steepest descent (SD) for QSM reconstruction. METHODS:Two convex projections, an obj...

journal_title：Magnetic resonance in medicine

authors： Deng W,Boada F,Poser BA,Schirda C,Stenger VA

更新日期：2015-02-01 00:00:00

abstract：:Functional magnetic resonance imaging (fMRI) has recently been adopted as an investigational tool in the field of neuroscience. The signal changes induced by brain activations are small ( approximately 1-2%) at 1.5T. Therefore, the signal-to-noise ratio (SNR) of the time series used to calculate the functional maps is...

journal_title：Magnetic resonance in medicine

authors： Parrish TB,Gitelman DR,LaBar KS,Mesulam MM

更新日期：2000-12-01 00:00:00