Diagnosis of superior sagittal sinus thrombosis by computerized tomography. Report of two cases.

Superior sagittal sinus thrombosis was diagnosed on computerized tomography (CT) scanning and was subsequently confirmed by angiography in two patients. Small ventricles and filling defects occurring within the sinus (the empty triangle sign) appeared to be highly suggestive of superior sagittal sinus thrombosis, and the association was confirmed angiographically. Potential pitfalls in the CT diagnosis of local obstruction of cerebral venous outflow are described and correlated with the natural history of the disease. The need for improved awareness of the CT appearance of occlusive disease of the dural venous sinuses is stressed.