Demonstration of focal hyperemia in acute cerebral infarction with iodine-123 iodoamphetamine.

Focal hyperemia is known to occur in regions of acute cerebral infarction. Presented here are two cases in which SPECT images with 125I-labeled iodoamphetamine demonstrated focal areas of increased tracer concentration associated with cerebral infarction. These results may have important implications regarding the physiology of iodoamphetamine in cerebral infarction and, in particular, whether the distribution of this tracer is related to regional blood flow in this setting. In addition, interpretation of iodoamphetamine images in cerebral infarction should include consideration of this finding.