Phase-contrast velocimetry with simultaneous fat/water separation.

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：PURPOSE:The oxygen extraction fraction (OEF) is an important biomarker for tissue-viability. MRI enables noninvasive estimation of the OEF based on the blood-oxygenation-level-dependent (BOLD) effect. Quantitative OEF-mapping is commonly applied using least-squares regression (LSR) to an analytical tissue model. Howeve...

journal_title：Magnetic resonance in medicine

authors： Domsch S,Mürle B,Weingärtner S,Zapp J,Wenz F,Schad LR

更新日期：2018-02-01 00:00:00

abstract：:A computer simulation program capable of demonstrating various artifacts, such as image distortion caused by metallic implants in MR imaging, is presented. The structure of the program allows for the implementation of various imaging situations as long as spins only experience weak interaction, i.e., the Bloch equatio...

journal_title：Magnetic resonance in medicine

authors： Olsson MB,Wirestam R,Persson BR

更新日期：1995-10-01 00:00:00

abstract：:To obtain a better understanding of the mechanisms underlying early changes in the brain water apparent diffusion coefficient (ADC) observed in cerebral ischemia, dynamic changes in the ADC of water and in the energy status were measured at postnatal day 8 or 9 in neonatal rat brains after cardiac arrest using 1H MRS/...

journal_title：Magnetic resonance in medicine

authors： van der Toorn A,Syková E,Dijkhuizen RM,Vorísek I,Vargová L,Skobisová E,van Lookeren Campagne M,Reese T,Nicolay K

更新日期：1996-07-01 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：:The spin-lattice relaxation time T1 of multicomponent tissues is often determined by fitting relaxation data to monoexponential functions. This process can lead to large errors in the relaxation time. We describe a procedure using chemical-shift imaging (CSI) which separates the NMR signal into water and lipid compone...

journal_title：Magnetic resonance in medicine

authors： Hornak JP,Smith AC,Szumowski J

更新日期：1990-03-01 00:00:00

abstract：:Manganese is a useful contrast agent for MRI of animals. Previously, it has been shown that systemic doses of MnCl(2) provide unique contrast in the rodent brain, enabling visualization of neuroarchitecture. The present work investigates the dose and temporal dependence of brain enhancement after i.v. administration o...

journal_title：Magnetic resonance in medicine

authors： Lee JH,Silva AC,Merkle H,Koretsky AP

更新日期：2005-03-01 00:00:00

abstract：:In a research environment, a magnetic resonance imaging system's manufacturer-supplied protection against excessive rf power deposition in the sample is often compromised. This paper presents a widely applicable scheme, based on a commonly available fuse, that simply and effectively limits the average rf power into a ...

journal_title：Magnetic resonance in medicine

authors： Hedges LK

更新日期：1989-02-01 00:00:00

abstract：:Proton-electron double-resonance imaging (PEDRI) was used to assess renal function by monitoring the flow of the exogenous nitroxide free radical proxyl carboxylic acid (PCA) through normal and injured kidneys in the living rat. Kidney damage was induced by treatment with 2-bromoethylamine (BEA), which provides a well...

journal_title：Magnetic resonance in medicine

authors： Seimenis I,Foster MA,Lurie DJ,Hutchison JM,Whiting PH,Payne S

更新日期：1998-08-01 00:00:00

abstract：:Intracranial vascular territories are usually visualized with the use of angiographic techniques. However, because it is difficult to visualize the distal vascular bed with any angiographic technique, it is also difficult to infer the parenchymal borders of vascular territories. Arterial spin labeling (ASL) MRI provid...

journal_title：Magnetic resonance in medicine

authors： Günther M

更新日期：2006-09-01 00:00:00

abstract：PURPOSE:Blood flow causes induced voltages via the magnetohydrodynamic (MHD) effect distorting electrograms (EGMs) made during magnetic resonance imaging. To investigate the MHD effect in this context MHD voltages occurring inside the human heart were simulated in an in vitro model system inside a 1.5 T MR system. MET...

journal_title：Magnetic resonance in medicine

authors： Buchenberg WB,Mader W,Hoppe G,Lorenz R,Menza M,Büchert M,Timmer J,Jung B

更新日期：2015-09-01 00:00:00

abstract：PURPOSE:MR safety at 7 Tesla relies on accurate numerical simulations of transmit electromagnetic fields to fully assess local specific absorption rate (SAR) safety. Numerical simulations for SAR safety are currently performed using models of healthy patients. These simulations might not be useful for estimating SAR in...

journal_title：Magnetic resonance in medicine

authors： Restivo MC,van den Berg CA,van Lier AL,Polders DL,Raaijmakers AJ,Luijten PR,Hoogduin H

更新日期：2016-01-01 00:00:00

abstract：:Optimization of experimental settings of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), like the contrast administration protocol, is of great importance for reliable quantification of the microcirculatory properties, such as the volume transfer-constant K(trans). Using system identification theory an...

journal_title：Magnetic resonance in medicine

authors： Aerts HJ,van Riel NA,Backes WH

更新日期：2008-05-01 00:00:00

abstract：PURPOSE:We sought to develop and test a clinically feasible 1-point Dixon, three-dimensional (3D) radial acquisition strategy to create isotropic 3D MR images of (129)Xe in the airspaces, barrier, and red blood cells (RBCs) in a single breath. The approach was evaluated in healthy volunteers and subjects with idiopathi...

journal_title：Magnetic resonance in medicine

authors： Kaushik SS,Robertson SH,Freeman MS,He M,Kelly KT,Roos JE,Rackley CR,Foster WM,McAdams HP,Driehuys B

更新日期：2016-04-01 00:00:00

abstract：PURPOSE:Spiral readouts combine several favorable properties that promise superior net sensitivity for diffusion imaging. The purpose of this study is to verify the signal-to-noise ratio (SNR) benefit of spiral acquisition in comparison with current echo-planar imaging (EPI) schemes. METHODS:Diffusion-weighted in vivo...

journal_title：Magnetic resonance in medicine

authors： Lee Y,Wilm BJ,Brunner DO,Gross S,Schmid T,Nagy Z,Pruessmann KP

更新日期：2021-04-01 00:00:00

abstract：:Imaging of stable paramagnetic spin probes in phantom objects and in vivo was evaluated using a RF time domain EPR spectrometer/imager operating at 300 MHz. Projections were collected using static magnetic field gradients and images were reconstructed using filtered back-projection techniques. Results from phantom obj...

journal_title：Magnetic resonance in medicine

authors： Afeworki M,van Dam GM,Devasahayam N,Murugesan R,Cook J,Coffin D,Larsen JH,Mitchell JB,Subramanian S,Krishna MC

更新日期：2000-03-01 00:00:00

abstract：:Magnetization exchange effects between the matrix macromolecules (e. g., collagen and proteoglycan) and water were examined in normal, deuterated, and proteoglycan-depleted articular cartilage. Relaxation results (T(2), T(1rho), and T(1)) suggested that a four-site exchange scheme provided an accurate model for articu...

journal_title：Magnetic resonance in medicine

authors： Lattanzio PJ,Marshall KW,Damyanovich AZ,Peemoeller H

更新日期：2000-12-01 00:00:00

abstract：:To investigate white matter (WM) development, voxelwise analyses of diffusion tensor MRI (DTMRI) data, acquired from 12 very preterm and 11 preterm infants with gestational ages (GA) ranging from 25 to 29 and 29 to 32 weeks, respectively, and 10 newborn normal term infants were performed. T(2) relaxation measures were...

journal_title：Magnetic resonance in medicine

authors： Rose SE,Hatzigeorgiou X,Strudwick MW,Durbridge G,Davies PS,Colditz PB

更新日期：2008-10-01 00:00:00

abstract：PURPOSE:The purpose of this study was to develop a three-dimensional black blood imaging method for simultaneously evaluating the carotid and intracranial arterial vessel walls with high spatial resolution and excellent blood suppression with and without contrast enhancement. METHODS:The delay alternating with nutatio...

journal_title：Magnetic resonance in medicine

authors： Xie Y,Yang Q,Xie G,Pang J,Fan Z,Li D

更新日期：2016-06-01 00:00:00

abstract：:Changes in the exchange rate of water across the blood-brain barrier, denoted k(w), may indicate blood-brain barrier dysfunction before the leakage of large-molecule contrast agents is observable. A previously proposed approach for measuring k(w) is to use diffusion-weighted arterial spin labeling to measure the vascu...

journal_title：Magnetic resonance in medicine

authors： St Lawrence KS,Owen D,Wang DJ

更新日期：2012-05-01 00:00:00

abstract：PURPOSE:To obtain multicontrast images including fat-suppressed contrast image, a novel multicontrast imaging method using an SSFP sequence with alternating RF flip angles is proposed. METHODS:The proposed method uses the balanced SSFP sequence with 2 flip angles. In general, the conventional balanced SSFP sequence ha...

journal_title：Magnetic resonance in medicine

authors： Kim J,Seo H,So S,Park H

更新日期：2018-10-01 00:00:00

abstract：PURPOSE:Evaluate the usefulness of single-shot and of interleaved spatiotemporally encoded (SPEN) methods to perform diffusion tensor imaging (DTI) under various preclinical and clinical settings. METHODS:A formalism for analyzing SPEN DTI data is presented, tailored to account for the spatially dependent b-matrix wei...

journal_title：Magnetic resonance in medicine

authors： Solomon E,Liberman G,Nissan N,Frydman L

更新日期：2017-03-01 00:00:00

abstract：:The aim of this study was to detect salvageable peri-infarction myocardium by MRI in rats after infarction, using with a double contrast agent (CA) protocol at 7 Tesla. Intravascular superparamagnetic iron oxide (SPIO) nanoparticles and an extracellular paramagnetic CA (Gd-DOTA) were used to characterize the peri-infa...

journal_title：Magnetic resonance in medicine

authors： Chapon C,Lemaire L,Franconi F,Marescaux L,Legras P,Denizot B,Le Jeune JJ

更新日期：2004-10-01 00:00:00

abstract：:Phosphorus NMR can measure myocardial tissue pH from the chemical shift of inorganic phosphate (Pi) in isolated buffer-perfused hearts, but in vivo the Pi peak originating from the myocardium is obscured by the resonance of 2,3-diphosphoglycerate (DPG) in the blood, making pH difficult to determine. Taking advantage o...

journal_title：Magnetic resonance in medicine

authors： Zahler R,Majumdar S,Frederick B,Laughlin M,Barrett E,Gore JC

更新日期：1991-02-01 00:00:00

abstract：:This article describes an EPR spectrometer specifically designed and constructed for EPR spectroscopy in humans. The spectrometer is based on a permanent magnet, suitable for measurements at 1200 MHz. The magnet has a full 50 cm gap between the poles, which facilitates accurate and comfortable placement of the subject...

journal_title：Magnetic resonance in medicine

authors： Salikhov I,Walczak T,Lesniewski P,Khan N,Iwasaki A,Comi R,Buckey J,Swartz HM

更新日期：2005-11-01 00:00:00

abstract：:The application of T1 rho an an alternative contrast parameter in high-field magnetic resonance histology (MRH) has been investigated. Spectroscopic measurements of T1 rho were performed on 5.75% agar and 1.0 mM MnCI2 phantoms at 9.4 T to validate the accuracy of the imaging measurements. Image studies were performed ...

journal_title：Magnetic resonance in medicine

authors： Engelhardt RT,Johnson GA

更新日期：1996-05-01 00:00:00

abstract：:Signal-to-noise ratio (SNR) is a major challenge to sodium magnetic resonance imaging. Phased array coils have been shown significantly improving SNR in proton imaging over volume coils. This study investigates SNR advantage of a 15-channel array head coil (birdcage volume coil for transmit/receive and 15-channel arra...

journal_title：Magnetic resonance in medicine

authors： Qian Y,Zhao T,Wiggins GC,Wald LL,Zheng H,Weimer J,Boada FE

更新日期：2012-12-01 00:00:00

abstract：PURPOSE:Segmentation of cardiac cine MRI data is routinely used for the volumetric analysis of cardiac function. Conventionally, 2D contours are drawn on short-axis (SAX) image stacks with relatively thick slices (typically 8 mm). Here, an acquisition/reconstruction strategy is used for obtaining isotropic 3D cine data...

journal_title：Magnetic resonance in medicine

authors： Odille F,Bustin A,Liu S,Chen B,Vuissoz PA,Felblinger J,Bonnemains L

更新日期：2018-05-01 00:00:00

abstract：PURPOSE:To develop methods for characterizing materials used in screen-printed MRI coils and improve signal-to-noise ratio (SNR) with new lower-loss materials. METHODS:An experimental apparatus was created to characterize dielectric properties of plastic substrates used in receive coils. Coils were fabricated by scree...

journal_title：Magnetic resonance in medicine

authors： Corea JR,Lechene PB,Lustig M,Arias AC

更新日期：2017-08-01 00:00:00

abstract：PURPOSE:For ultrahigh field (UHF) MRI, the expected local specific absorption rate (SAR) distribution is usually calculated by numerical simulations using a limited number of generic body models and adding a safety margin to take into account intersubject variability. Assessment of this variability with a large model d...

journal_title：Magnetic resonance in medicine

authors： Meliadò EF,van den Berg CAT,Luijten PR,Raaijmakers AJE

更新日期：2019-03-01 00:00:00