Introduction QUICK TAKE The MR CLEAN Trial Intravenous alteplase administered within 4.5 hours after symptom onset is the only reperfusion therapy with proven efficacy in patients with acute ischemic stroke.1 However, well-recognized limitations of this therapy include the narrow therapeutic time window and contraindications such as recent surgery, coagulation abnormalities, and a history of intracranial hemorrhage.2 Moreover, intravenous alteplase appears to be much less effective at opening...
