MR angiography of the persistent trigeminal artery variant

To evaluate the MR angiographic findings of the persistent trigeminal artery variant (PTAV) and to discuss its clinical implications.

We reviewed time-of-flight MR angiography including individual source imaging in three patients with PTAV, which had been recognized as an incidental finding on conventional arteriography. In all cases, MR angiography was performed at 1.5 T.

MR angiography demonstrated the PTAVs as hyperintense structures originating from the precavernous portion of the internal carotid artery, running within or very close to the Meckel cave and near the trigeminal nerve root, and reaching the posterior fossa (cerebellar arteries) without joining the basilar artery. Spin echo imaging failed to demonstrate the PTAVs.

Source imaging of MR angiography helped demonstrate PTAV and its adjacent structure. Knowledge of the presence and course of this anomalous vessel is useful for various treatment strategies.