[Computerized tomography in aneurysms of the posterior cranial fossa].

The authors discuss the clinical usefulness of CT scan in patients with ruptured posterior fossa aneurysms. Among 164 patients after SAH, in 17 the bleeding was caused by aneurysms located in posterior fossa. The exact diagnosis of the bleeding during 5 days after SAH was possible in 94% of the patients, that is similar as in supratentorial aneurysms. The characteristic symptoms of SAH in these aneurysms was the symmetric presence of blood in basal cisterns, intraventricular haemorrhage and, in consequence,--hydrocephalus. Aneurysms of bifurcation of BA were characterized by presence of blood in interpeduncular cistern; this phenomenon was not observed in PICA aneurysms. The aneurysms of BA were more often seen in direct CT-Scan.