Axial noncontrasted CT demonstrates high-density blood in the suprasellar cistern,
the ambient cisterns, the anterior hemispheric fissure, and the sylvian fissures.
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
Subarachnoid hemorrhage from ruptured
posterior communicating aneurysm