Quick case to show good angio technique. CTA with bulbous carotid terminus

Recons read as SCA aneurysm

Angio — co-dominant verts — weak injection — there is slipstreaming of unopacified blood from left vert, making evaluation suboptimal.  Its not diagnostic

A volume-rendered reconstruction of rotational angiography looks like this may be a basilar terminus fenestration. But location is unusual — mid- or lower basilar fenestrations are more common.

Optimal projection, good injection to overcome left vert inflow, magnification, lack of movement — all good technique — confirm presence of an unusual fenestration.

Stereos

Slipstreaming of blood/contrast can be used as an indirect sign of continuity, but the above images are more important