The magnetic resonance imaging (MRI) acute stroke protocol includes T2, fluid attenuated inversion recovery (FLAIR), gradient recalled echo (GRE), MR angiography (MRA), diffusion-weighted imaging (DWI), and perfusion-weighted imaging (PWI) and can be acquired in 15–20 minutes. Diffusion-weighted MRI (DWI) is an excellent tool to detect acute cerebral infarcts and to distinguish these from chronic infarcts, in patients with stroke or transient ischemic attack. MRI is an effective tool to select patients who are optimal candidates for acute stroke therapy. MRI is as reliable as computed tomography (CT) in the identification of acute intracerebral hemorrhage and can therefore be used as the sole imaging modality for evaluating patients with acute stroke. MRI is superior to CT in identifying the underlying cause of intracerebral hemorrhage. MRA and venography are ideal imaging modalities for evaluation of cerebrovascular pathology such as arterial stenosis or occlusions, dissections, aneurysms, and venous thrombosis.
