Brain and vascular imaging of acute stroke.

Contemporary imaging technologies permit the rapid and accurate assessment of the acute stroke patient. These studies form the underpinning of all therapeutic approaches. Although unenhanced computed tomography remains the principal diagnostic examination to exclude hemorrhagic stroke, multimodal computed tomography and magnetic resonance imaging can be use to assess cerebral perfusion and may reveal the ischemic penumbra, thus leading to better patient selection for intravenous or intra-arterial reperfusion strategies.