A fusiform dilatation of proximal portion of the right posterior communicating artery with adjacent tiny daughter sac, measuring about 5.9 x 3.9 mm. There is an associated abrupt change in caliber of the distal portion of posterior communicating artery (vasospasm). Ruptured aneurysm of right posterior communicating artery is suggested.
A focal outpouching of the proximal portion of the left posterior communicating artery is seen, measuring about 3.8 x 2.9 mm. An unruptured aneurysm of the left posterior communicating artery is suggested.