"Pseudo-delta sign" on computed tomography in an extremely acute stage of superior sagittal sinus thrombosis--a case report.

A case of superior sagittal sinus (SSS) thrombosis with a "pseudo-delta sign" on computed tomography (CT) is reported. The so-called "empty delta sign," which usually appears following contrast enhancement, is reliable in the CT diagnosis of SSS thrombosis but may not appear, it is said, in the extremely acute stage. In this patient, however, the "empty delta sign" appeared with precontrast CT scans and disappeared with postcontrast CT scans, "pseudo-delta sign," in the extremely acute stage of SSS thrombosis. On the precontrast CT, blood surrounding the sagittal sinus outlined it; when contrast was given, it became dense with blood.