DIFFUSION-WEIGHTED MR TOMOGRAPHY - A PROM ISING MR TECHNIQUE FOR EARLY RECOGNITION OF CEREBRAL-ISCHEMIA

Purpose: The aim of this study was to show the temporal and spatial ev olution of ischaemia over time using diffusion-weighted magnetic reson ance imaging, and to correlate the extent of ischaemia with the postmo rtem infarct size after 24 hours. Material and methods: In 8 rats foca l cerebral ischaemia was induced by intravascular occlusion of the mid dle cerebral artery. The evolution of the ischaemic lesion was examine d over 180 min with an experimental MR scanner. Results: Diffusion-wei ghted magnetic resonance imaging displayed a hyperintense area in the lateral part of the putamen as early as 5 min after the onset of ischa emia. The mean volume of ischaemia on diffusion mapping after 5 min wa s 62.5 +/- 12.9 mu l and increased to 224.4 +/- 48.5 mu l after 180 mi n. This correlated well with the corrected infarct volume at postmorte m examination (194.0 +/- 23.1 mu l, r = 0.72, p <0.05) using the TTC s taining. Conclusion: Diffusion-weighted magnetic resonance imaging is a reliable tool in the early diagnosis of cerebral ischaemia. Due to t he non-invasiveness this method can be used for therapy monitoring and might help to develope new therapeutic strategies.