Abstract:
:The sensitivity of diffusion-weighted MRI was compared to that of T2-weighted MRI following temporary middle cerebral artery occlusion (MCA-O) for 33 min followed by 4 h of reperfusion in rats. Diffusion-weighted spin-echo images using strong gradients (b value of 1413 s/mm2) demonstrated a significant increase in signal intensity in ischemic regions as early as 14 min after onset of ischemia in comparison to the normal, contralateral hemisphere (p less than 0.05). This hyperintensity returned to baseline levels during reperfusion. T2-weighted images showed no evidence of brain injury during the temporary occlusion. In three rats subjected to permanent MCA-O, diffusion-weighted MRI demonstrated an increased signal intensity on the first image following occlusion and continued to increase during the 4-h observation period. T2-weighted images failed to demonstrate significant injury until approximately 2 h after MCA-O. Signal intensity ratios of ischemic to normal tissues were greater in the diffusion-weighted images than in the T2-weighted MR images at all time points (p less than 0.05). Close anatomical correlation was found between the early and sustained increase in diffusion-weighted MRI signal intensity and localization of infarcts seen on post-mortem histopathology.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Mintorovitch J,Moseley ME,Chileuitt L,Shimizu H,Cohen Y,Weinstein PRdoi
10.1002/mrm.1910180106subject
Has Abstractpub_date
1991-03-01 00:00:00pages
39-50issue
1eissn
0740-3194issn
1522-2594journal_volume
18pub_type
杂志文章abstract:PURPOSE:To verify MR measurements of myocardial extracellular volume fraction (ECV) based on clinically applicable T1-mapping sequences against ECV measurements by radioisotope tracer in pigs and to relate the results to those obtained in volunteers. METHODS:Between May 2016 and March 2017, 8 volunteers (25 ± 4 years,...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27938
更新日期:2020-02-01 00:00:00
abstract:PURPOSE:To demonstrate feasibility of transceive phase mapping with the PLANET method and its application for conductivity reconstruction in the brain. METHODS:Accuracy and precision of transceive phase (ϕ± ) estimation with PLANET, an ellipse fitting approach to phase-cycled balanced steady state free precession (bSS...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.27958
更新日期:2020-02-01 00:00:00
abstract:PURPOSE:To propose and evaluate a deep learning model for rapid and accurate calculation of myocardial T1 /T2 values based on a previously proposed Bloch equation simulation with slice profile correction (BLESSPC) method. METHODS:Deep learning Bloch equation simulations (DeepBLESS) models are proposed for rapid and ac...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.28321
更新日期:2020-11-01 00:00:00
abstract:PURPOSE:The aims of this study were (i) to establish a robust and fast method to quantify hepatocellular phosphorus compounds in molar concentration on a 3T clinical scanner, (ii) to evaluate its reproducibility, and (iii) to test its feasibility for a use in large cohort studies. METHOD:Proton-decoupled (31) P magnet...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24835
更新日期:2014-05-01 00:00:00
abstract::Healthy human brain diffusion anisotropy maps derived from standard spin echo diffusion tensor imaging (DTI) were compared with those using fluid-attenuated inversion recovery (FLAIR) preparation prior to DTI to null the signal from cerebrospinal fluid (CSF). Consistent comparisons entailed development of DTI postproc...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10204
更新日期:2002-08-01 00:00:00
abstract::Images of hyperpolarized 3He were acquired during breath-hold in four healthy volunteers with the use of an optimized 3D gradient-echo sequence. The images were compared with existing 2D gradient-echo methods. The average SNR from a 13-mm-thick slice in the peripheral lung was 1.4 times greater with 3D. In the airways...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20164
更新日期:2004-09-01 00:00:00
abstract::A novel method for detecting neural activity in functional magnetic resonance imaging (fMRI) data is introduced. It is based on canonical correlation analysis (CCA), which is a multivariate extension of the univariate correlation analysis widely used in fMRI. To detect homogeneous regions of activity, the method combi...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/1522-2594(200102)45:2<323::aid-mrm1041>3.0
更新日期:2001-02-01 00:00:00
abstract:PURPOSE:A MR thermometry (MRT) method with field monitoring is proposed to improve the measurement of small temperature variations induced in brain MRI exams. METHODS:MR thermometry experiments were performed at 7 Tesla with concurrent field monitoring and RF heating. Images were reconstructed with nominal k-space tra...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.28501
更新日期:2021-03-01 00:00:00
abstract::To investigate the dependency of T(1) relaxation on mechanical strain in articular cartilage, quantitative magnetic resonance T(1) imaging experiments were carried out on cartilage before/after the tissue was immersed in gadolinium contrast agent and when the tissue was being compressed (up to ∼ 48% strains). The spat...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22933
更新日期:2011-06-01 00:00:00
abstract:PURPOSE:To improve quantification of myocardial blood flow using a fast T1 mapping technique using highly constrained back projection reconstruction (HYPR)-accelerated acquisition. METHODS:A major source of error in the measurement of myocardial blood flow (MBF) using MRI is the nonlinear relationship between image si...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24958
更新日期:2014-09-01 00:00:00
abstract:PURPOSE:To develop a fast protocol for measuring T1 values in the internal carotid artery (ICA), to validate this technique with in vitro measurements, and to evaluate its reproducibility. METHODS:A modified Look-Locker sequence was optimized to enable rapid determination of T1 in the ICA at 3T. T1 values from the ICA...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26325
更新日期:2017-06-01 00:00:00
abstract:PURPOSE:Lung pO2 mapping with (3)He MRI assumes that the sources of signal decay with time during a breath-hold are radiofrequency depolarization and oxygen-dependent T1 relaxation, but the method is sensitive to other sources of spatio-temporal signal change such as diffusion. The purpose of this work was to assess th...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24779
更新日期:2014-03-01 00:00:00
abstract::MRI of myocardial perfusion observed with an extracellular contrast agent has proven valuable for the detection of coronary artery disease. During contrast enhancement transient dark rim artifacts are sometimes visible, complicating diagnosis and quantification. In this work a quantification of the frequency offsets c...
journal_title:Magnetic resonance in medicine
pub_type: 临床试验,杂志文章
doi:10.1002/mrm.21723
更新日期:2008-10-01 00:00:00
abstract::Nonlinear feedback interactions have been shown to amplify contrast due to small differences in resonance frequency arising from microscopic susceptibility variations. Determining whether the selectivity of feedback-based contrast enhancement for small resonance frequency variations remains valid even in the presence ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21584
更新日期:2009-04-01 00:00:00
abstract:PURPOSE:To remove nuisance signals (e.g., water and lipid signals) for (1) H MRSI data collected from the brain with limited and/or sparse (k, t)-space coverage. METHODS:A union-of-subspace model is proposed for removing nuisance signals. The model exploits the partial separability of both the nuisance signals and the...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25635
更新日期:2016-02-01 00:00:00
abstract::Hyperpolarized (HP) 129Xe can be dissolved in biologically compatible lipid emulsions while maintaining sufficient polarization for in vivo vascular imaging. For xenon in Intralipid 30%, in vitro spectroscopy at 2 T yielded a chemical shift of 197 +/- 1 ppm with reference to xenon gas, a spin-lattice relaxation time T...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1522-2594(199905)41:5<1058::aid-mrm2
更新日期:1999-05-01 00:00:00
abstract::As the static magnetic field strength used in human magnetic resonance imaging increases, the wavelength of the corresponding radiofrequency field becomes comparable to the dimensions of the coil and volume of interest. The dielectric resonance effects that arise in this full wavelength regime may be partially compens...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20583
更新日期:2005-08-01 00:00:00
abstract:PURPOSE:To use quantitative susceptibility mapping (QSM) to investigate changes in cartilage canals in the distal femur of juvenile goats after their surgical transection. METHODS:Chondronecrosis was surgically induced in the right medial femoral condyles of four 4-day-old goats. Both the operated and control knees we...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.26214
更新日期:2017-03-01 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
pub_type: 杂志文章
doi:10.1002/mrm.25155
更新日期:2015-02-01 00:00:00
abstract::We applied MRI to the in vivo detection of spontaneous colorectal tumors in a unique mouse model, the Fox Chase Cancer Center (FCCC) ApcMIN mouse. Unlike other Min (multiple intestinal neoplasia) strains, FCCC ApcMIN animals develop an appreciable number of tumors in the large intestine, which makes them an appropriat...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20175
更新日期:2004-09-01 00:00:00
abstract::We describe a doubly tuned radiofrequency (RF) local coil probe designed specifically for performing in vivo image-localized spectroscopy. The probe was designed using principles developed in connection with the counter-rotating-current (CRC) and planar-pair loop gap resonators for magnetic resonance imaging (MRI). Th...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910060303
更新日期:1988-03-01 00:00:00
abstract::Measurement of myocardial and brain perfusion when using exogenous contrast agents (CAs) such as gadolinium-DTPA (Gd-DTPA) and MRI is affected by the diffusion of water between compartments. This water exchange may have an impact on signal enhancement, or, equivalently, on the longitudinal relaxation rate, and could t...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1188
更新日期:2001-08-01 00:00:00
abstract::The aim of this study was to quantify changes in thoracic aortic wall shear stress (WSS) in asymptomatic patients with Marfan syndrome (MFS) compared with healthy controls. WSS in the thoracic aorta was quantified based on time-resolved 3D phase contrast MRI with three-directional velocity encoding (4D flow MRI, tempo...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.24562
更新日期:2013-10-01 00:00:00
abstract::For in vivo magnetic resonance imaging at high field (> or =3 T) it is essential to consider the homogeneity of the active B(1) field (B(1)+), particularly if surface coils are used for RF transmission. A new method is presented for highly rapid B(1)+ magnitude mapping. It combines the double angle method with a B(1)-...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20896
更新日期:2006-06-01 00:00:00
abstract::MnCl(2) was injected intrathecally through the cisterna magna in rats, allowing infusion of divalent manganese ions (Mn(++)) into the CSF space and thence into the brain, without breaking the blood-brain barrier (BBB). Mn(++) uptake and washout dynamics in the brain were measured by serial T(1)-weighted MRI and EPI T(...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.20047
更新日期:2004-05-01 00:00:00
abstract::Atherosclerosis initially develops predominantly at the aortic root and carotid origin, where effective visualization in mice requires efficient cardiac and respiratory gating. The present study sought to first compare the high-resolution MRI gating performance of two digital gating strategies using: 1) separate cardi...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21308
更新日期:2007-12-01 00:00:00
abstract:PURPOSE:High-resolution intravascular (IV) MRI is susceptible to degradation from physiological motion and requires high frame-rates for true endoscopy. Traditional cardiac-gating techniques compromise efficiency by reducing the effective scan rate. Here we test whether compressed sensing (CS) reconstruction and ungate...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.25436
更新日期:2015-08-01 00:00:00
abstract::Flow measurement methods for functional MRI (fMRI) are desirable as they are more closely tied to neuronal activity than the commonly used blood oxygenation techniques. In this work we introduce a flow-based functional imaging method. The method, called flow enhancement of signal intensity (FENSI), is an extension of ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.21325
更新日期:2007-08-01 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
pub_type: 杂志文章
doi:10.1002/(sici)1522-2594(200003)43:3<375::aid-mrm9>
更新日期:2000-03-01 00:00:00
abstract::The combination of an in-plane B(1) sensitivity encoding (SENSE) technique with a simultaneous multiple-slice B(0) field step technique (multiple-acquisition micro B(0) array (MAMBA)) has produced high scan time reduction factors (R < or = 8). In this study, two slices were acquired simultaneously in combination with ...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10464
更新日期:2003-06-01 00:00:00