[Significance of CT in the assessment of risk due to cerebral vasospasm following subarachnoid hemorrhage].

The relationship between the amount and localization of blood in the subarachnoid space and the occurrence of vasospasms was studied in 100 patients with aneurysmal subarachnoid haemorrhage with cerebral vasospasm as complication. In the control group comprised 100 patients in whom angiography revealed no vasospasm. Within one week of subarachnoid haemorrhage all patients underwent computerized tomography of the head. The examination was initially conducted without and subsequently with the administration of contrast medium in a 2 mm thick layer. The amount and distribution of blood were evaluated according to Fisher scale. Follow-up cerebral angiography was performed in most cases in the second week after haemorrhage. In the studied group the occurrence of blood in the subarachnoid space was disclosed in 71 (71%) of the patients. In most cases it was present as clots in basal cisterns. In the control group the presence of blood was found in 32 (32%) of patients, this being usually diffused in subarachnoid space. The results obtained, as well as those quoted from other works, confirm the usefulness of computerized tomography in prognosing the risk of cerebral vasospasms following subarachnoid haemorrhage. However, the method is not to be overestimated.