Persistent primitive trigeminal artery imaged by three-dimensional computed tomography angiography--two case reports.

Three-dimensional computed tomography (3D CT) angiography was used to investigate two cases of persistent primitive arteries. 3D CT angiography and 3D CT demonstrated a persistent primitive trigeminal artery variant penetrating the lateral edge of the posterior clinoid process and running to the posterior medial side, and a persistent primitive trigeminal artery perforating the canal of the posterior clinoid process and the petrosal bone junction. 3D CT angiography can delineate these persistent primitive arteries and the anatomy relative to the bone structure simultaneously, so is very useful to identify the arterial line where the canal is penetrated.