title: Bleeding patterns in ruptured posterior fossa aneurysms: a CT study.
abstract: Computed tomography of the brains in 20 patients with acute rupture of posterior fossa aneurysms was reviewed and analyzed retrospectively. Findings were compared with those from 44 cases described in the literature and with the findings in ruptured supratentorial aneurysms. Extravasated blood was observed in 19 of 20 patients (95%); intraventricular hemorrhage (IVH) in 17 of 20 (85%); and subarachnoid hemorrhage (SAH) in 13 of 20 (65%). These values were significantly higher than those previously reported and suggest that, during the acute phase of rupture, extravasated blood may be detected with the same frequency in either infratentorial or supratentorial ruptured aneurysms. Subarachnoid hemorrhage was accompanied by IVH, prominent in the fourth ventricle and without intraparenchymal hematoma, in 11 patients (55%). This pattern is highly suggestive of ruptured posterior fossa aneurysms. Intraventricular hemorrhage without SAH was noted in five patients (25%) and specifically represented ruptured posterior inferior cerebellar artery aneurysms. Subarachnoid hemorrhage without IVH was noted in only two patients (10%).
authors.affiliation: Department of Diagnostic Radiology, University of Maryland Medical System, Baltimore 21201.
authors.forename: N
authors.initials: N
authors.lastname: Sadato
authors.forename: Y
authors.initials: Y
authors.lastname: Numaguchi
authors.forename: D
authors.initials: D
authors.lastname: Rigamonti
authors.forename: M
authors.initials: M
authors.lastname: Salcman
authors.forename: F E
authors.initials: FE
authors.lastname: Gellad
authors.forename: T
authors.initials: T
authors.lastname: Kishikawa
mesh_terms: D000328:Adult; D000368:Aged; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology; D002552:Cerebral Ventricles; D003388:Cranial Fossa, Posterior; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications* / Q000000981:diagnostic imaging / Q000453:epidemiology; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012422:Rupture, Spontaneous / Q000453:epidemiology; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology; D014057:Tomography, X-Ray Computed