Salvage of the PWI/DWI mismatch up to 48h from stroke onset leads to favorable clinical outcome

Abstract

Background and Purpose: In acute ischemic stroke perfusion/diffusion-weighted image, mismatch using magnetic resonance imaging approximates the ischemic penumbra. For early time windows, mismatch salvage improves clinical outcomes, but uncertainty exists at later time epochs. We hypothesized that (a) mismatch may exist up to 48h; (b) the proportion of mismatch salvage is time independent; and (c) when salvaged, it improves clinical outcomes. Methods: Magnetic resonance imaging was performed within 48h of ischemic stroke. Perfusion-weighted image was defined by relative Tmax two-second delay. Perfusion/diffusion-weighted image mismatch was the perfusion-weighted image not overlapped by the di..