What is the best imaging method for patients with a presumed acute stroke?

Abstract

Evidence-based answer: It depends on whether the stroke is ischemic or hemorrhagic. For early detection of ischemic stroke, magnetic resonance imaging (MRI) using diffusion-weighted imaging (DWI) is highly sensitive and specific, whereas computed tomography (CT) is less sensitive but about as specific (strength of recommendation [SOR]: B, a meta-analysis of lower quality RCTs). MRI using DWI and CT are probably comparable for detecting acute hemorrhagic stroke (SOR: B, a cohort study). When thrombolysis is being considered and hemorrhage must be ruled out rapidly, either test is acceptable if it can be performed and interpreted within 45 minutes of patient arrival, although MRI typically costs about twice as much as CT (SOR: C, expert opinion).