The AAN published the guideline, "The Role of Diffusion and Perfusion MRI for the Diagnosis of Acute Ischemic Stroke," in the July 13, 2010, issue of Neurology®.
The guideline finds that MRI scans are better than CT scans for diagnosing possible acute ischemic stroke presenting in the first 12 hours of symptom onset. MRI scans can help distinguish acute ischemic stroke from medical conditions with similar symptoms. The study also reports there is insufficient evidence to support or refute the value of perfusion-weighted imaging (PWI) in diagnosing acute ischemic stroke. Baseline diffusion-weighted imaging (DWI) volume should be considered useful in predicting baseline clinical stroke severity and final lesion volume in anterior-circulation stroke syndromes.