The study of cerebral ischemic reversibility: Part I. A review of positron imaging studies.

Predictions about tissue viability and clinical recovery following cerebral ischemic events can be more accurately made once quantitative information is available regarding cerebral blood flow and concomitant cerebral metabolism. To date, positron imaging data has, on a limited basis, been available in regional centers and has helped determine issues of ischemic reversibility. The stages of cerebral ischemia are reviewed along with the physiologic data available via positron imaging. Expansion of this data base by studying the natural history of ischemic lesions with follow-up studies and by studying individuals before and after intervention therapies is the next step in further understanding the pathophysiology of cerebral ischemia.