Mechanism of detection of acute cerebral ischemia in rats by diffusion-weighted magnetic resonance microscopy.
Published
Journal Article
BACKGROUND AND PURPOSE: The aim of this study was to measure apparent diffusion coefficients in rat brain tissue exposed to ouabain, glutamate, and N-methyl-D-aspartate and to compare them with apparent diffusion coefficients found in acute cerebral ischemia. METHODS: The apparent diffusion coefficient was measured using magnetic resonance microscopy in four groups of Sprague-Dawley rats after occlusion of the right middle cerebral artery and ipsilateral common carotid artery (n = 7), after ouabain exposure (n = 6), during glutamate exposure (n = 7), or during N-methyl-D-aspartate exposure (n = 3). Ouabain, glutamate, and N-methyl-D-aspartate were applied via an intracerebrally implanted microdialysis membrane. RESULTS: Three hours after the induction of focal cerebral ischemia, a 33% reduction in the apparent diffusion coefficient was observed in the right dorsolateral corpus striatum and olfactory cortex. After ouabain exposure, reductions in the apparent diffusion coefficient were observed within a 1,500-microns radius of the microdialysis membrane. Quantitative analysis revealed that apparent diffusion coefficient values in ischemic and ouabain-exposed tissue fell within the same range. Glutamate and N-methyl-D-aspartate reduced the brain tissue apparent diffusion coefficient by 35% and 40%, respectively. CONCLUSIONS: On the basis of these findings, we conclude that ischemia-induced apparent diffusion coefficient reductions are likely caused by a shift of extracellular to intracellular water.
Full Text
Duke Authors
Cited Authors
- Benveniste, H; Hedlund, LW; Johnson, GA
Published Date
- May 1992
Published In
Volume / Issue
- 23 / 5
Start / End Page
- 746 - 754
PubMed ID
- 1374575
Pubmed Central ID
- 1374575
International Standard Serial Number (ISSN)
- 0039-2499
Digital Object Identifier (DOI)
- 10.1161/01.str.23.5.746
Language
- eng
Conference Location
- United States