Figure 13a. Anterior fossa dural AVF. (a) Unenhanced CT scan shows intracranial hemorrhage at the frontal base. (b) Left internal carotid angiogram shows a dural AVF (arrow) that is fed by the ethmoidal artery and drains into the leptomeningeal vein, which demonstrates varices (arrowheads). (c) Left internal carotid angiogram obtained after clipping of the draining vein shows disappearance of the AVF.