Two tales: Hemorrhagic transformation but not parenchymal hemorrhage after thrombolysis is related to severity and duration of ischemia : MRI study of acute stroke patients treated with intravenous tissue plasminogen activator within 6 hours

Intracerebral hemorrhage represents the most feared complication of treatment with intravenous tissue plasminogen activator. We studied whether perfusion-weighted imaging and diffusion-weighted imaging has the potential to identify patients at risk of severe intracerebral hemorrhage after treatment with intravenous tissue plasminogen activator. We analyzed data of prospectively studied MRI selected acute ischemic stroke patients treated with intravenous tissue plasminogen activator within 6 hours. All patients were examined by perfusion- and diffusion-weighted imaging < or =6 hours. Perfusion- and diffusion-weighted imaging lesion volumes were calculated. Hemorrhagic transformation was assessed on follow-up CT or MRI and diagnosed as hemorrhagic transformation, parenchymal hemorrhage, or symptomatic intracerebral hemorrhage according to ECASS II criteria. Of 152 patients, hemorrhagic transformation was seen in 60 (39.5%), parenchymal hemorrhage in 15 (9.9%), and symptomatic intracerebral hemorrhage in 4 (2.6%). Multiple logistic regression analysis identified onset to treatment time after 3 to 6 hours (P