Imaging strategy for acute stroke therapy

New MR imaging methods provide us with a hitherto unimaginable wealth of information on the pathophysiologic mechanisms operative in acute stroke. The only evidence-based acute stroke therapy, thrombolysis with IV tPA, only requires a CT to exclude brain hemorrhage before treatment. In PROACT 2 (Prolyse in Acute Cerebral Thromboembolism) locoregional thrombolysis with prourokinase improved the frequency of independent outcome. The only imaging methods used in this trial were a brain CT to exclude patients with brain hemorrhage and extended early infarct signs and a classical angiogram to demonstrate the presence of an M1 or M2 segment occlusions. In principle these therapies can be applied without using sophisticated MR or CT techniques. In this brief review we discuss the potential role of these novel techniques before application of intravenous or intraarterial thrombolysis.