Refining and testing the PWI-DWI mismatch hypothesis

Abstract

Mismatch between a perfusion-weighted image (PWI) deficit and a smaller diffusion-weighted image (DWI) lesion, putatively provides a visual representation of the ischemic penumbra. The mismatch concept is certainly biologically plausible and there is a growing body of supportive evidence. Indeed, many clinical centers have begun to utilize PWI and DWI in the selection of potential acute stroke thrombolysis patients. Unfortunately, the hypothesis that patients with PWI-DWI mismatch are the optimal responders to thrombolytic therapy remains unproven. Furthermore, there is at this point no accepted or standardized definition of exactly what constitutes mismatch. Multiple perfusion and diffusion..