ISCHEMIC LESION VOLUMES IN ACUTE STROKE BY DIFFUSION-WEIGHTED MAGNETIC-RESONANCE-IMAGING CORRELATE WITH CLINICAL OUTCOME

Diffusion-weighted magnetic resonance imaging detects ischemic injury within minutes after onset, and has been used to demonstrate drug effi cacy in animal models of stroke, In 50 patients diagnosed with acute i schemic stroke (<24-hour duration) within the middle cerebral artery t erritory, lesion volume was measured by diffusion-weighted imaging, Th irty-four patients also had volumes measured by T2-weighted imaging ch ronically (median time, 7.5 weeks; mean, 15.9 weeks), Clinical severit y was measured by the National Institutes of Health Stroke Scale Score and the Barthel index, Acute lesion volumes correlated with the acute stroke scale score (r = 0.56), the chronic stroke scale score (r = 0. 63), and chronic lesion volumes (r = 0.84). Chronic volumes correlated with the chronic stroke scale score (r = 0.86) and the Barthel index (r = -0.60). When only cortically based lesions were considered, the c orrelations relating acute lesion volume measured by diffusion-weighte d imaging (r = 0.61) and chronic lesion volume measured by T2-weighted imaging (r = 0.90) to the chronic stroke scale score were higher, The se results provide evidence that lesion volumes determined by diffusio n-weighted imaging acutely may be predictive of clinical severity and outcome, and may support a role for diffusion-weighted imaging in the assessment of acute stroke therapies in clinical trials.