Measuring extracellular volume fraction by MRI: First verification of values given by clinical sequences.

abstract：PURPOSE:As prescribed and reliable geometrical entities, phantoms have served as indispensable validation tools in a variety of MR-related topics. Though a number of phantoms have been conceived, certain applications may warrant highly customized geometries. The purpose of this study was to demonstrate the expediency o...

journal_title：Magnetic resonance in medicine

authors： Kasten JA,Vetterli T,Lazeyras F,Van De Ville D

更新日期：2016-01-01 00:00:00

abstract：:Nitroprusside, a vasodilatory nitric oxide donor, is clinically used during vascular surgery and to lower blood pressure in acute hypertension. This article reports a novel application of blood flow (BF) and blood oxygenation level dependent (BOLD) MRI on an 11.7T scanner to image the rat chorioretinal BF and BOLD cha...

journal_title：Magnetic resonance in medicine

authors： Shih YY,Li G,Muir ER,De La Garza BH,Kiel JW,Duong TQ

更新日期：2012-10-01 00:00:00

abstract：:Chemically-fixed nervous tissues are well-suited for high-resolution, time-intensive MRI acquisitions without motion artifacts, such as those required for brain atlas projects, but the aldehyde fixatives used may significantly alter tissue MRI properties. To test this hypothesis, this study characterized the impact of...

journal_title：Magnetic resonance in medicine

authors： Shepherd TM,Thelwall PE,Stanisz GJ,Blackband SJ

更新日期：2009-07-01 00:00:00

abstract：:Quantitative 1H MRS to determine cerebral metabolite patterns and MRI to determine CSF flow were applied to 12 patients with ventricular dilation-Group A, cortical atrophy (N = 5); or Group B, hydrocephalus (N = 7)- and in 9 normal controls. While mean brain water (Group A = 80% +/- 6; Group B = 86% +/- 5; normal = 85...

journal_title：Magnetic resonance in medicine

authors： Bluml S,McComb JG,Ross BD

更新日期：1997-03-01 00:00:00

abstract：:This work presents a method that allows for the assessment of 3D murine myocardial motion in vivo at microscopic resolution. Phase-contrast (PC) magnetic resonance imaging (MRI) at 17.6 T was applied to map myocardial motion in healthy mice along three gradient directions. High-resolution velocity maps were acquired a...

journal_title：Magnetic resonance in medicine

authors： Herold V,Mörchel P,Faber C,Rommel E,Haase A,Jakob PM

更新日期：2006-05-01 00:00:00

abstract：:Diffusion-weighted imaging suffers from motion artifacts and relatively low signal quality due to the long echo times required to permit the diffusion encoding. We investigated the inclusion of a noncylindrical fourth gradient coil, dedicated entirely to diffusion encoding, into the imaging system. Standard three-axis...

journal_title：Magnetic resonance in medicine

authors： Feldman RE,Scholl TJ,Alford JK,Handler WB,Harris CT,Chronik BA

更新日期：2011-12-01 00:00:00

abstract：:Calibration of the spatial sensitivity functions of coil arrays is a crucial element in parallel magnetic resonance imaging (PMRI). The most common approach has been to measure coil sensitivities directly using one or more low-resolution images acquired before or after accelerated data acquisition. However, since it i...

journal_title：Magnetic resonance in medicine

authors： McKenzie CA,Yeh EN,Ohliger MA,Price MD,Sodickson DK

更新日期：2002-03-01 00:00:00

abstract：PURPOSE:To propose a phase error correction scheme for monopolar time-interleaved multi-echo gradient echo water-fat imaging that allows accurate and robust complex-based quantification of the proton density fat fraction (PDFF). METHODS:A three-step phase correction scheme is proposed to address a) a phase term induce...

journal_title：Magnetic resonance in medicine

authors： Ruschke S,Eggers H,Kooijman H,Diefenbach MN,Baum T,Haase A,Rummeny EJ,Hu HH,Karampinos DC

更新日期：2017-09-01 00:00:00

abstract：:We studied the fluxes of a potassium congener (Rb(+)) in mouse hearts by (87)Rb MRS at 8.4T. The hearts were loaded with Rb(+) by perfusion with Krebs-Henseleit buffer, in which 50% of K(+) was substituted with Rb(+). We initiated Rb(+) efflux by changing the perfusion medium to Rb(+)-free buffer. Spectra were acquire...

journal_title：Magnetic resonance in medicine

authors： Jilkina O,Xiang B,Kuzio B,Rendell J,Kupriyanov VV

更新日期：2005-05-01 00:00:00

abstract：:It is demonstrated that birdcage resonators, satisfying conditions of quadrature operation and radiofrequency field homogeneity, can be realized in practice on formers of non-circular cross section described by an equation of the form (x/a)n + (y/b)n = 1 where a and b are constants and n > or = 2 is an integer. Using ...

journal_title：Magnetic resonance in medicine

authors： Riauka TA,De Zanche NF,Thompson R,Vermeulen FE,Capjack CE,Allen PS

更新日期：1999-06-01 00:00:00

abstract：PURPOSE:To develop an analytically based algorithm for rapid optimization of the local radiofrequency magnetic (B1+) field intensity for a given radiofrequency power through a transmit array. The analytical nature of the method will yield insight to optimization requirements and provides a valuable reference for numeri...

journal_title：Magnetic resonance in medicine

authors： Carluccio G,Collins CM,Erricolo D

更新日期：2014-01-01 00:00:00

abstract：PURPOSE:To investigate the relative gain in sensitivity of five histology coils designed in-house to accommodate tissue sections of various sizes and compare with commercial mouse head coils. METHODS:The coil set was tailored to house tissue sections ranging from 5 to1000 µm encased in either glass slides or coverslip...

journal_title：Magnetic resonance in medicine

authors： Hoang DM,Voura EB,Zhang C,Fakri-Bouchet L,Wadghiri YZ

更新日期：2014-05-01 00:00:00

abstract：:High-order radiofrequency transmitter coils are described that permit, in the context of NMR imaging, a knowledgeable trade-off between coil complexity and the degree of inhomogeneity over a specified volume of space. A mathematical formulation of high-order coils is developed for an axially symmetric polarizing dc fi...

journal_title：Magnetic resonance in medicine

authors： Sotgiu A,Hyde JS

更新日期：1986-02-01 00:00:00

abstract：:We used high-field (13)C NMR (18.8 T) to assign unambiguously the isotopic shifts induced by the deuterium substitutions of the H3(proR) and H3(proS) hydrogens of (2-(13)C) glutamate in extracts of the brain from deuterated animals. Monodeuterated H3R or H3S glutamate diastereoisomers were produced stereospecifically ...

journal_title：Magnetic resonance in medicine

authors： Rodrigues TB,Violante IR,Cerdán S

更新日期：2010-04-01 00:00:00

abstract：:The echo-planar k-space trajectory can be used as the basis for any two-dimensional selective pulse. The main application is spectral-spatial pulses, which must be based on the echo-planar trajectory. In this paper we show how echo-planar spin-echo (EPSE) pulses may be designed. ...

journal_title：Magnetic resonance in medicine

authors： Pauly J,Spielman D,Macovski A

更新日期：1993-06-01 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：:Simulations of dynamic susceptibility contrast (DSC) MRI are frequently performed by assuming a certain shape for the input function and the microvascular response function. However, to investigate the influence of parameters that will affect the shape of the input function, a more complex model of the human vasculatu...

journal_title：Magnetic resonance in medicine

authors： van Osch MJ,Vonken EJ,Wu O,Viergever MA,van der Grond J,Bakker CJ

更新日期：2003-09-01 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:Continuously moving table (CMT) MRI is a high throughput technique that has multiple applications in whole-body imaging. In this work, CMT MRI based on golden angle (GA, 111.246° azimuthal step) radial sampling is developed at 3 Tesla (T), with the goal of increased flexibility in image reconstruction using arb...

journal_title：Magnetic resonance in medicine

authors： Sengupta S,Smith DS,Welch EB

更新日期：2015-12-01 00:00:00

abstract：:Quantification of peak velocity is important in the assessment of stenotic flow jets in patients with congenital heart disease. Phase-contrast magnetic resonance underestimates peak velocities. Hence, clinically Doppler ultrasound is used as the reference standard for assessing stenoses. It is possible to accurately m...

journal_title：Magnetic resonance in medicine

authors： Steeden JA,Jones A,Pandya B,Atkinson D,Taylor AM,Muthurangu V

更新日期：2012-06-01 00:00:00

abstract：:A single slice of z-magnetization is used to generate high-speed images. The slice selection step is achieved using two sin-sinc pulses. This procedure eliminates the need for continual slice gradient reversal, a requirement for the FLASH technique. The RAPID imaging method has less inherent T1 and/or T2 dependence th...

journal_title：Magnetic resonance in medicine

authors： Brooks WM,Brereton IM,Doddrell DM

更新日期：1987-08-01 00:00:00

abstract：:For clinical 31P MR spectroscopic imaging (MRSI) studies, where signal averaging is necessary, some improvement of sensitivity and spatial response function may be achieved by acquiring data over a spherical k-space volume and varying the number of averages acquired in proportion to the desired spatial filter. Eight d...

journal_title：Magnetic resonance in medicine

authors： Hugg JW,Maudsley AA,Weiner MW,Matson GB

更新日期：1996-09-01 00:00:00

abstract：:This contribution reports the first direct and noninvasive observation of cerebral glucose in normal anesthetized rats (n = 16) using short-echo-time localized proton NMR spectroscopy (2.35 T, STEAM, TR = 6000 ms, TE = 20 ms, 125 microliters). In addition to resonances from N-acetyl aspartate (NAA), glutamate, total c...

journal_title：Magnetic resonance in medicine

authors： Gyngell ML,Michaelis T,Hörstermann D,Bruhn H,Hänicke W,Merboldt KD,Frahm J

更新日期：1991-06-01 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 incoherent displacement of water in living tissues is of considerable interest because of the widespread use of diffusion-weighted MRI, for which image contrast is based on the water apparent diffusion coefficient (ADC). It has been hypothesized that the decrease in water ADC associated with brain injury is primar...

journal_title：Magnetic resonance in medicine

authors： Sehy JV,Ackerman JJ,Neil JJ

更新日期：2002-07-01 00:00:00

abstract：:The recently developed technique of gradient, high-resolution magic-angle spinning NMR (g-hr-MAS-NMR) spectroscopy was applied to the study of ex vivo human lipoma and liposarcoma tissue. Compared with conventional 1H-NMR, the g-hr-MAS method yielded a large improvement in spectral resolution and permitted the detecti...

journal_title：Magnetic resonance in medicine

authors： Millis KK,Maas WE,Cory DG,Singer S

更新日期：1997-09-01 00:00:00

abstract：:The utility of a noninvasive steady state susceptibility-contrast MRI technique for continuous measurement of relative cerebral blood volume (rCBV) during global transient ischemia and subsequent hyperemia in a feline ischemia model is demonstrated. The measurements were obtained during a 10-min period of occlusion an...

journal_title：Magnetic resonance in medicine

authors： Hamberg LM,Boccalini P,Stranjalis G,Hunter GJ,Huang Z,Halpern E,Weisskoff RM,Moskowitz MA,Rosen BR

更新日期：1996-02-01 00:00:00

abstract：PURPOSE:Quantitative mapping of the native T1 of the heart using the modified look-locker inversion recovery (MOLLI) technique provides high quality diagnostic information without requiring contrast agents. Previous work has considered the effects of T2 relaxation on MOLLI T1 measurements, finding that the T1 measured ...

journal_title：Magnetic resonance in medicine

authors： Robson MD,Piechnik SK,Tunnicliffe EM,Neubauer S

更新日期：2013-09-01 00:00:00

abstract：PURPOSE:MUSSELS is a one-step iterative reconstruction method for multishot diffusion weighted (msDW) imaging. The current work presents an efficient implementation, termed IRLS MUSSELS, that enables faster reconstruction to enhance its utility for high-resolution diffusion MRI studies. METHODS:The recently proposed M...

journal_title：Magnetic resonance in medicine

authors： Mani M,Aggarwal HK,Magnotta V,Jacob M

更新日期：2020-06-01 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