FIG 1. Gadolinium-enhanced CTA images obtained in a 63-year-old man with sudden-onset, severe headache.
A, Axial 1.25-mm gadolinium-enhanced CTA image shows the right posterior communicating artery (arrow).
B-F, Reconstructed images show the middle and anterior cerebral arteries (B), anterior communicating artery region (C), left posterior communicating artery (D), vertebrobasilar junction and basilar artery (E), and right posterior inferior cerebellar artery origin (F).