Magnetic resonance evaluation of stroke.

Stroke is not a specific disease but is, instead, a symptom complex reflecting destruction of brain tissue by cerebrovascular disease. Several different specific diseases are included in the "stroke" category, including intra- and extracerebral hemorrhage as well as ischemic infarction. These different types of stroke have major differences regarding etiology, management, and prognosis. The goal of stroke imaging is to diagnose the type of stroke at clinical presentation, allowing prompt and appropriate management. Magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), and magnetic resonance spectroscopy (MRS) provide powerful noninvasive means to evaluate the pathologic and metabolic changes that occur in acute stroke. These techniques allow the early detection of stroke and greatly increase the ability to determine the etiology of the stroke. One or more of these methods will surely become a standard means of evaluating acute stroke. The information provided, combined with new stroke therapies, should result in improved patient outcome.