title: Pseudodelta sign on computed tomography: an indication of bilateral interhemispheric hemorrhage.
abstract: The "pseudodelta sign" is introduced as an indicator of interhemispheric hemorrhage. This sign, appearing in computed tomography (CT) scans, consists of hyperattenuated extra-axial blood surrounding blood flowing in the superior sagittal sinus, which shows lower attenuation. To determine the prevalence of interhemispheric hemorrhage and the pseudodelta sign in patients with post-traumatic extra-axial hemorrhage, the authors reviewed the charts and CT scans of 198 such patients. The patients had been admitted to a tertiary-care hospital between Jan. 1, 1986, and Dec. 1, 1990. Interhemispheric hemorrhage was visible in 18 cases; the pseudodelta sign was seen in 14 of these. In 8 of the 14 cases the interhemispheric hemorrhage consisted of bilateral subdural hematoma, and in 3 it consisted of unilateral subdural hematoma. In the remaining three cases the appearance of the interhemispheric blood was nonspecific, and the hemorrhage may have been subdural or subarachnoid. The pseudodelta sign may be a good indicator of interhemispheric hemorrhage in either the subdural or subarachnoid space.
authors.affiliation: Department of Radiological Sciences and Diagnostic Imaging, Foothills Hospital, Calgary, Alta.
authors.forename: L M
authors.initials: LM
authors.lastname: Numerow
authors.forename: T C
authors.initials: TC
authors.lastname: Fong
authors.forename: C J
authors.initials: CJ
authors.lastname: Wallace
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging*; D014695:Cerebral Ventriculography; D003392:Cranial Sinuses / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006408:Hematoma, Subdural / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*