Figure 2. Massive subarachnoid and intraventricular hemorrhage. Axial nonenhanced computer tomography demonstrates a large “bright” or hyper attenuating dense subarachnoid hemorrhage throughout the perimesencephalic cistern (arrow) and along the tentorium (double arrows). The subarachnoid blood in the basilar cisterns has refluxed into the 4th (double arrowheads) and 3rd (arrowhead) ventricles. There is marked hydrocephalus. An arterio-venous malformation (please refer to Figure 8), was the etiology of this subarachnoid hemorrhage.