Campbell BCV, et al. - After searching PubMed for randomized trials published in English between January 1, 2006 and March 1, 2019, researchers conducted this systematic review and meta-analysis to ascertain if perfusion imaging can recognize patients with salvageable brain tissue with symptoms 4.5 hours or more from stroke onset or with symptoms on waking who might benefit from thrombolysis. Of the 414 patients included in the three trials, alteplase given to 213 patients and placebo was given to 201. Compared to placebo, those with ischemic stroke 4.5-9 hours from stroke onset or wake-up stroke with salvageable brain tissue who were treated with alteplase attained better functional outcomes. Alteplase had a higher rate of symptomatic intracerebral hemorrhage, but this increase did not negate the overall thrombolysis net benefit.