Presentation
Headaches
Patient Data




There is a moderate stenosis of the basilar artery just proximal to the origin right AICA.
There is a focal outpouching in the anterior aspect of the basilar artery after the origin of the right AICA with a neck larger than the actual diameter of the outpouching. This apperance suggests a blood blister-like aneurysm.

The red arrow shows the wide-neck basilar aneurysm.
Case Discussion
The proximal narrowing of the basilar artery is either due to sequela of a previous dissection or noncalcified atherosclerosis. Blood blister-like aneurysm are known to arise post-dissection amongst other etiologies.