Value of computed tomography in the prediction of cerebral vasospasm after aneurysm rupture.

The relationship between high density (HD) on computed tomographic (CT) scans (which indicates a collection of blood in the subarachnoid space) and cerebral vasospasm was studied in 177 patients with ruptured aneurysm. The development of cerebral vasospasm was confirmed at the high rate of 84.6% in 26 cases where HD was demonstrated on the CT scan within 4 days after subarachnoid hemorrhage (SAH). In 8 cases where HD was not found on the CT scan obtained within 4 days after SAH, no cerebral vasospasm was seen. However, no relationship was found between HD and the occurrence of cerebral vasospasm in cases in which CT was performed after the 5th day of disease. It is suggested that CT performed within 4 days after SAH may give important information for predicting cerebral vasospasm.