Does a relative perfusion measure predict cerebral infarct size?

Backround & Purpose: The present study tested whether or not a relative measure of cerebral blood flow is sufficient to predict irreversible tissue damage following focal cerebral ischemia and reperfusion in the rat suture model. Methods: In rats, the middle cerebral artery was occluded (MCAO) for 1h followed by 1h reperfusion (8 animals with constant hematocrit; 7 animals with decreased hematocrit due to withdrawal of arterial reference blood without compensation). Radiolabeled microspheres were injected into the left ventricle before, 30min post-MCAO and 30min post-reperfusion, and absolute (aCBF) and relative…