Hypoplastic
P1 Segment
Post embolization
left vertebral angiogram (left) in a 15 year-old with a thalamic arteriovenous malformation. There is a hypoplastic right P1 segment
(arrow) with asymmetric supply
of the P1 vessels to the posterior circulation (circles). Right internal carotid injection (right) shows a large posterior communicating
artery (open arrow) supplying the
remainder of the posterior circulation on the right.
