Abstract:
:Radial imaging protocols suitable for monitoring water transport in biopolymer and food materials during processes such as drying and rehydration are developed and tested on a well-characterized model sample. This model consisted of a randomly packed bed of Sephadex beads with varying water content. The results are interpreted with theoretical models for the dependence of the initial water magnetization, transverse relaxation, and diffusive attenuation on water content for two slice-selective radial imaging pulse sequences. It is shown that volume shrinkage and changes in packing density complicate the dependence of the initial magnetization on water content, so that the transverse relaxation rate provides the most reliable monitor of water content. Radial imaging is shown to offer many advantages over conventional two-dimensional imaging whenever the sample can be made with cylindrical symmetry.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Hills BP,Babonneau Fdoi
10.1016/0730-725x(94)91238-rsubject
Has Abstractpub_date
1994-01-01 00:00:00pages
1065-74issue
7eissn
0730-725Xissn
1873-5894pii
0730-725X(94)91238-Rjournal_volume
12pub_type
杂志文章abstract::In-plane flow quantification in MRI offers the potential for assessing vessel patency, and both volume flow rate and flow velocity. These techniques will have definite future impact on MR angiography. The method used in this paper employs motion artifact suppression technique (MAST) gradients to refocus spins travelli...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(88)90409-2
更新日期:1988-05-01 00:00:00
abstract::It is often desirable to separate voxels that contain signal from tissue along with measurement noise from those that contain purely measurement noise. Generally, this separation called thresholding utilizes only the magnitude portion of the images. Recently, methods have been developed that utilize both the magnitude...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2009.05.008
更新日期:2009-11-01 00:00:00
abstract::This work addresses the special problems of measuring flow velocity distributions in rock by NMR methods. Specifically, these problems are to measure very slow flows as well as flows in the presence of background magnetic field gradients caused by heterogeneities of the rock. We modify a stimulated echo sequence for u...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(96)00110-5
更新日期:1996-01-01 00:00:00
abstract::The fast Fourier flow technique offers a convenient way for extremely exact flow measurements. In combination with ECG gating, arterial flow can be studied. The total acquisition time for a single measurement is about 10 s, an ECG-gated cine sequence can be acquired in about 4 min. Fast Fourier flow can, therefore, be...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(88)90473-0
更新日期:1988-07-01 00:00:00
abstract::The apparent diffusion coefficient (ADC) measured using magnetic resonance imaging methods provides information on microstructural properties of biological tissues, and thus has found applications as a useful biomarker for assessing changes such as those that occur in ischemic stroke and cancer. Conventional pulsed gr...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2010.10.002
更新日期:2011-04-01 00:00:00
abstract::Susceptibility-weighted imaging (SWI) is a valuable technique for high-resolution imaging of brain vasculature that greatly benefits from the emergence of higher field strength MR scanners. Autocalibrating partially parallel imaging techniques can be employed to reduce lengthy acquisition times as long as the decrease...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2008.08.003
更新日期:2009-05-01 00:00:00
abstract::Changes in both blood flow and blood oxygenation determine the functional MRI (fMRI) signal. In the present study factors responsible for blood oxygenation (e.g., FiO(2)) were held constant so that changes in pixel count would above all reflect changes in regional cerebral blood flow (rCBF). Continuous positive airway...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(00)00229-0
更新日期:2001-01-01 00:00:00
abstract:PURPOSE:This study aimed to further investigate the effects of agmatine on brain edema in the rats with middle cerebral artery occlusion (MCAO) injury using magnetic resonance imaging (MRI) monitoring and biochemical and histopathologic evaluation. MATERIALS AND METHODS:Following surgical induction of MCAO for 90min, ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2013.03.026
更新日期:2013-09-01 00:00:00
abstract::The purpose of this study was to evaluate a magnetic resonance imaging (MRI) technique for quantifying the proton density water fraction (PDWF) as a biomarker of bone marrow cellularity. Thirty-six human bone marrow specimens from 18 donors were excised and subjected to different measurements of tissue composition: PD...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2014.03.005
更新日期:2014-11-01 00:00:00
abstract::Various analogs of NMR and MRI are now technically possible in optics; specifically, high-resolution laser-pulse shaping and complex pulse sequence generation with well-defined phase shifts has been demonstrated. Here we summarize this technology and discuss the potential for these methods to enhance optical functiona...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2003.08.024
更新日期:2003-12-01 00:00:00
abstract::Gels consist of crosslinked polymer network swollen in solvent. The network of flexible long-chain molecules traps the liquid medium they are immersed in. Some gels undergo abrupt volume change, a phase transition process, by swelling-shrinking in response to external stimuli changes in solvent composition, temperatur...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(02)00639-2
更新日期:2003-02-01 00:00:00
abstract::Tumor aggressiveness and response to therapy are influenced by the extravascular extracellular space fraction (EESF) of the malignant tissue. The EESF may, therefore, be an important prognostic parameter for cancer patients. The aim of this study was to investigate whether gadopentetate dimeglumine (Gd-DTPA)-based dyn...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2007.06.003
更新日期:2008-02-01 00:00:00
abstract::T1 and T2 relaxation times are fundamental parameters for signal contrast behaviour in MRI. A number of ex vivo relaxometry studies have dealt with the magnetic field dispersion of T1. By means of multicenter study within the frame of the COMAC BME Concerted Action on Tissue Characterization by MRI and MRS, the in viv...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章,多中心研究
doi:10.1016/0730-725x(93)90202-o
更新日期:1993-01-01 00:00:00
abstract::The purpose of this study was to assess the benefits of a 3 T scanner and an eight-channel phased-array head coil for acquiring three-dimensional PRESS (Point REsolved Spectral Selection) proton (H-1) magnetic resonance spectroscopic imaging (MRSI) data from the brains of volunteers and patients with brain tumors rela...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2006.07.012
更新日期:2006-12-01 00:00:00
abstract::Glioblastoma Multiforme is the most common and most aggressive type of brain tumors. Although accurate prediction of Glioblastoma borders and shape is absolutely essential for neurosurgeons, there are not many in silico platforms that can make such predictions. In the current study, an automatic patient-specific simul...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2019.12.012
更新日期:2020-05-01 00:00:00
abstract::Several recent articles have assessed the relative efficiency of nuclear magnetic resonance (NMR) pulse sequences. One consideration that has received little attention is the effect on image contrast of displaying images without information on the sign of the reconstructed signals. The radiofrequency receivers current...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(84)90193-0
更新日期:1984-01-01 00:00:00
abstract::BOLD-contrast functional magnetic resonance imaging (MRI) was used to assess the evolution of tumor oxygenation and blood flow after administration of four different anesthetics: pentobarbital (60 mg/kg), ketamine/xylazine (80/8 mg/kg), fentanyl/droperidol (0.078/3.9 mg/kg), and isoflurane (1.5%). Gradient echo sequen...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2004.02.005
更新日期:2004-09-01 00:00:00
abstract::Diffusion in the extracellular and intracellular spaces (ECS and ICS, respectively) was evaluated in excised spinal cords, before and after cell swelling induced by glutamate, by high b-value q-space diffusion MR of specific markers and water. The signal decays of deuterated tetramethylammonium (TMA-d(12)) chloride, a...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2004.01.029
更新日期:2004-06-01 00:00:00
abstract::The ability to evaluate empirical diffusion MRI acquisitions for quality and to correct the resulting imaging metrics allows for improved inference and increased replicability. Previous work has shown promise for estimation of bias and variance of generalized fractional anisotropy (GFA) but comes at the price of compu...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2019.03.021
更新日期:2019-06-01 00:00:00
abstract::Relaxation time measurements were carried out during the preacute stage of lesion progression in an animal model of demyelination created in the internal capsule (ic) area of the rat brain using lysophosphatidyl choline (LPC). T1 and T2 were determined both before and after 36 h of lesion creation. Histology carried o...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2004.11.010
更新日期:2005-01-01 00:00:00
abstract::The analysis of functional magnetic resonance imaging (fMRI) data involves multiple stages of data pre-processing before the activation can be statistically detected. Spatial smoothing is a very common pre-processing step in the analysis of functional brain imaging data. This study presents a broad perspective on the ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2007.08.006
更新日期:2008-05-01 00:00:00
abstract:PURPOSE:To introduce a simple analytical formula for estimating T2 from a single Double-Echo in Steady-State (DESS) scan. METHODS:Extended Phase Graph (EPG) modeling was used to develop a straightforward linear approximation of the relationship between the two DESS signals, enabling accurate T2 estimation from one DES...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2016.12.018
更新日期:2017-05-01 00:00:00
abstract::In porous material research, one main interest of nuclear magnetic resonance diffusion (NMR) experiments is the determination of the shape of pores. While it has been a longstanding question if this is in principle achievable, it has been shown recently that it is indeed possible to perform NMR-based diffusion pore im...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2013.03.027
更新日期:2013-09-01 00:00:00
abstract::We present a novel approach to the nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) analysis of complex samples with nontrivial distribution of longitudinal relaxation rate R(1). Parametrically enabled relaxation filters with double and multiple inversion (PERFIDI) aim to separate signals arising ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2006.12.001
更新日期:2007-05-01 00:00:00
abstract::Dynamic contrast-enhanced magnetic resonance imaging (MRI) is widely used for measuring perfusion and blood volume, especially cerebral blood volume (CBV). In case of blood-brain barrier (BBB) disruption, the conventional techniques only partially determine the pharmacokinetic parameters of contrast medium (CM) exchan...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/s0730-725x(00)00223-x
更新日期:2000-12-01 00:00:00
abstract::Selective inversion recovery (SIR) is a quantitative magnetization transfer (qMT) method that provides estimates of parameters related to myelin content in white matter, namely the macromolecular pool-size-ratio (PSR) and the spin-lattice relaxation rate of the free pool (R1f), without the need for independent estimat...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2020.01.014
更新日期:2020-05-01 00:00:00
abstract:PURPOSE:To develop a method for mapping the B1 transmit (B1t) and B1 receive (B1r) fields from two gradient echo datasets each with a different flip angle and from these two images obtain accurate T1 and proton density (PD) maps of the brain. METHODS:A strategically acquired gradient echo (STAGE) data set is collected...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2017.10.006
更新日期:2018-02-01 00:00:00
abstract::A new approach is introduced for non-rigid registration of a pair of magnetic resonance images (MRI). It is a generalization of the demons algorithm with low computational cost, based on local information augmentation (by integrating multiple images) and balanced implementation. Specifically, a single deformation that...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2020.09.013
更新日期:2020-12-01 00:00:00
abstract::We studied 26 cases of abdominal aortic aneurysm with magnetic resonance imaging (MRI), computed tomography (CT), ultrasonography (US), and angiography. Data acquired were compared to those obtained at surgery. Diameter of the aneurysm was correctly defined in all cases by CT and MRI, while angiography underestimated ...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/0730-725x(90)90089-k
更新日期:1990-01-01 00:00:00
abstract::Rapid maturational brain changes occur during adolescence--a time associated with risk-taking behaviors and improvements in cognition. The present study examined the relationship between white matter (WM) microstructure, impulsive behavior and response inhibition in female and male adolescents. Twenty-one healthy adol...
journal_title:Magnetic resonance imaging
pub_type: 杂志文章
doi:10.1016/j.mri.2006.03.012
更新日期:2006-09-01 00:00:00