Neuroimaging of Acute Stroke.

Acute stroke is the clinical manifestation of disrupted blood flow or bleeding in the central nervous system. Imaging supports the clinical diagnosis and can aide in acute treatment decision making and guide information on prognosis. Features that are delineated include the parenchyma and the blood vessels. Parenchymal characteristics include early ischemic changes, established infarct and tissue at risk (penumbra), and hemorrhage. Vessel pathology includes arterial and venous steno-occlusive disease and vascular malformations. In the presence of a vessel occlusion, vessel imaging can assess collateral flow. This article outlines the role of neuroimaging as applied to patients presenting with acute stroke.