Cerebral hemodynamics in human acute ischemic stroke: A study with diffusion- and perfusion-weighted magnetic resonance imaging and SPECT

Nineteen patients with acute ischemic stroke (<24 hours) underwent diffusio n-weighted and perfusion-weighted (PWI) magnetic resonance imaging at the a cute stage and week later. Eleven patients also underwent technetium-99m et hyl cysteinate dimer single-photon emission computed tomography (SPECT) at the acute stage. Relative (ischemic vs. contralateral control) cerebral blo od flow (relCBF), relative cerebral blood volume, and relative mean transit time were measured in the ischemic core, in the area of infarct growth, an d in the eventually viable ischemic tissue on PWI maps. The relCBF was also measured from SPECT. There was a curvilinear relationship between the relC BF measured from PWI and SPECT (r = 0.854; P < 0.001). The tissue proceedin g to infarction during the follow-up]lad significantly lower initial CBF an d cerebral blued volume values on PWI maps (P < 0.001) than the eventually viable ischemic tissue had. The best value for discriminating the area of i nfarct growth from the eventually viable ischemic tissue was 48% for PWI re lCBF and 87% for PWI relative cerebral blood volume. Combined diffusion and perfusion-weighted imaging enables one to detect hemodynamically different subregions inside the initial perfusion abnormality. Tissue survival may b e different in these subregions and may be predicted.