PET and MR studies of experimental focal stroke.

Positron emission tomography (PET) and MR have been compared with histochemical pathology to show affected tissue areas in rat brain after right middle cerebral artery (MCA) occlusion combined with temporary bilateral common carotid artery occlusion in Long Evans rats. The glucose metabolic rate was 65 +/- 8 mumol/100 ml/min in the right cortical gray matter corresponding to the occluded middle cerebral artery territory and 93 +/- 8 mumol/100 ml/min in the corresponding (left) normal side. Infarcted tissue showed decreased PET activity and increased signal in MR T2-weighted scans ipsilateral to the MCA occlusion. These regions correspond to a zone of focal infarction identified in coronal tissue sections stained with 3-4-5 triphenyl tetrazolium chloride. This study demonstrates that PET can be used to study glucose utilization in rat stroke model in vivo and noninvasively.