Signs of cerebral venous thrombosis on head CT scan

(A) Noncontrast head CT shows a hyperdense thrombosed cortical vein (arrow).
(B) Noncontrast head CT shows a hyperdensity in the torcula (small arrowhead) and the straight sinus (large arrowhead), a direct sign of dural sinus thrombosis (the dense triangle sign).
(C) Head CT shows non-filling of the confluent sinus after contrast injection (the empty delta sign).