Guo C, et al. - In the present study, the researchers sought to examine wake-up ischemic stroke (WUIS) intravenous thrombolytic therapy driven by rapid MRI. They gathered data from patients with acute ischemic stroke within 4.5 h and from WUIS individuals with an uncertain onset time window, who received the treatment of rt-PA intravenous thrombolytic therapy in the hospital from November 2006 to April 2018. In total, 253 individuals received rt-PA intravenous thrombolysis after head MRI evaluation; this involved 177 cases of acute ischemic stroke and 76 cases of WUIS. When the treatment was guided by rapid MRI, no statistical difference was found between the baseline data from the acute ischemic stroke patients with 4.5 h onset time window and the baseline data from the WUIS patients with undetermined onset time window. In addition, no significant statistical differences were noted in National Institutes of Health Stroke Scale score, Rankin scale score, symptomatic bleeding, death and aggravation of the disease between the two groups at 24 h, 3 days, and 7 days after admission. Under the guidance of rapid MRI, more WUIS patients will benefit from the rt-PA intravenous thrombolytic therapy, according to the characteristic of the undetermined onset time window of WUIS.