Postoperative changes on brain SPECT imaging after aneurysmal subarachnoid hemorrhage. A potential pitfall in the evaluation of vasospasm.

Overview

Serial brain SPECT imaging was performed on patients after subarachnoid hemorrhage and surgical clipping of intracranial aneurysms. A total of 20 HMPAO scans were performed on 9 patients in whom clinical vasospasm did not develop. Areas of diminished regional cerebral blood flow (rCBF) were found near the operative site in 17 of 20 studies, which did not correlate with the patients' neurologic condition and were suggestive of postoperative edema. Brain SPECT imaging has a potentially valuable role to play in the evaluation of postoperative patients susceptible to vasospasm; however, it is important to be aware of postoperative changes in rCBF that are not related to vasospasm.