An analysis of cerebral blood flow in acute closed-head injury using technetium-99m-HMPAO SPECT and computed tomography.

Technetium-99m-hexamethylpropyleneamine (HMPAO) SPECT and x-ray CT were compared in 15 patients with acute closed-head injury. There were 44 focal lesions in all. Fifteen (34%) lesions were seen on both x-ray and SPECT. Seventeen (39%) lesions were seen only on SPECT. Twelve (27%) of the lesions were seen on x-ray tomography only. Of the lesions seen on x-ray tomography but not on SPECT, two were subarachnoid hemorrhage, two were thin subdural hematomas, and eight were contusions. This study shows that SPECT can detect focal disturbances of cerebral blood flow that are not seen on x-ray tomography. It also suggests that there are two types of contusions: those with a decreased cerebral blood flow (i.e., detectable on SPECT) and those with a cerebral blood flow equal to that of the surrounding brain.