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Incidence of apparent restricted diffusion in three different models of cerebral infarction

Item Type:Article
Title:Incidence of apparent restricted diffusion in three different models of cerebral infarction
Creators Name:Norris, D.G. and Niendorf, T. and Hoehn-Berlage, M. and Kohno, K. and Schneider, E.J. and Hainz, P. and Hropot, M. and Leibfritz, D.
Abstract:High speed magnetic resonance imaging (MRI) and short diffusion times are used to investigate the appearance of restricted diffusion in three different models of cerebral infarction. The models are: the middle cerebral artery occlusion (MCAO) model in the rat, the carotid occlusion model in the gerbil, and the Rose Bengal microvascular occlusion model in the rat. All three were investigated for 16 b-values equally spaced between 10 and 1510 s/mm2 using two distinct experiments. In the ct (constant time) experiment, the diffusion time was held constant at 11.7 ms while the b-value was varied with the gradient strength. In the cg (constant gradient) experiment, the gradient strength was held constant and the b-value increased by varying the diffusion time from 4.4 to 11.7 ms. A monoexponential decay of the signal intensity with b-value in the ct experiment accompanied by nonmonoexponential (NME) decay in the cg experiment is indicative of restricted diffusion. As this phenomenon is detectable only at short diffusion times, it cannot be due to restriction by impermeable membranes, and we have thus termed this apparent restriction. For the MCAO model and the carotid occlusion model, apparent restriction was found both inside the infarct territory and in some regions outside it. No definite evidence for restriction was found for the Rose Bengal model, which was, however, only studied from 24 h post-insult.
Keywords:NMR Imaging, Apparent Restricted Diffusion, Cerebral Infarction, Animals, Rats
Source:Magnetic Resonance Imaging
Page Range:1175-1182
Official Publication:https://doi.org/10.1016/0730-725X(94)90083-4
PubMed:View item in PubMed

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