Legend Axial noncontrasted CT demonstrates high-density blood in the suprasellar cistern, the ambient cisterns, the anterior hemispheric fissure, and the sylvian fissures.

Legend Arteriogram demonstrates a saccular aneurysm arising at the origin of the posterior communicating artery. Saccular aneurysms are typically located in the circle of Willis, especially the anterior communicating artery (30 to 35%), posterior communicating artery (30 to 35%), and middle cerebral artery trifurcation (20%). Key words: angiography vascular

Brain Diagnosis: Subarachnoid hemorrhage from ruptured posterior communicating aneurysm