Thalamo-mesencephalic Branches of the Posterior Cerebral Artery: a 3D Rotational Angiography Study.

The prevalence of a proper "Artery of Percheron" type IIb PTA seems to be higher than previously reported. A fetal type P1-origin may be predictive of a type IIa/b PTA emanating from contralateral P1. 3D-RA may be useful for planning PCA interventions, as impairment of TM branches is a severe risk.