Abstract
Recent randomized control trial (RCTs) showed evidence that intravenous thrombolysis (t-PA) was beneficial in patients up to 4.5 hours from onset selected based on computed tomography. In order to extend the therapeutic time window, we have tried to select stroke patients using imaging who seem to have the effect of t-PA. Some RCTs have failed to show the beneficial evidence of t-PA in the patients selected based on apparent mismatch, thus some refinements are needed. Recently, a more precise method of evaluating mismatched tissue is being developed. Co-registration of diffusion-weighted image (DWI) and perfusion-weighted image (PWI) allows a more precise estimate of the mismatched volume than volumetric method, which is a simple subtraction of DWI from PWI spatial relationships, and lesion topography is taken into consideration. Re-analysis of EPITHET and the analysis of EPITHET/DEFUSE combined dataset in which patients were selected using co-registration mismatch showed the benefit of t-PA and this method may become standard after further advancement of technology.
