title: Tight Sylvian cisterns associated with hyperdense areas mimicking subarachnoid hemorrhage on computed tomography--four case reports.
abstract: Four patients with supratentorial mass lesions (two chronic subdural hematomas, one acute epidural hematoma, and one acute subdural hematoma) showed hyperdense sylvian cisterns on computed tomography (CT). Association of subarachnoid hemorrhage was suspected initially, but was excluded by intraoperative observation or postoperative lumbar puncture. CT showed disappearance of the hyperdense areas just after evacuation of the mass lesions. The hyperdense areas are probably a result of the partial volume phenomenon or concentrations of calcium deposits rather than abnormally high hematocrit levels, which were not found in these patients.
authors.affiliation: Department of Critical Care and Emergency Medicine, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Shimizu
authors.forename: M
authors.initials: M
authors.lastname: Endo
authors.forename: S
authors.initials: S
authors.lastname: Kan
authors.forename: T
authors.initials: T
authors.lastname: Kitahara
authors.forename: T
authors.initials: T
authors.lastname: Ohwada
authors.forename: K
authors.initials: K
authors.lastname: Fujii
mesh_terms: D000058:Accidental Falls; D000063:Accidents, Traffic; D000328:Adult; D000368:Aged; D002535:Cerebral Aqueduct / Q000000981:diagnostic imaging*; D002908:Chronic Disease; D003128:Coma / Q000209:etiology; D003399:Craniotomy; D003937:Diagnosis, Differential; D016489:Head Injuries, Closed / Q000150:complications; D006406:Hematoma / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery; D006801:Humans; D008297:Male; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging*; D013702:Temporal Lobe / Q000098:blood supply / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D014949:Wounds, Nonpenetrating / Q000150:complications