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