MR-ANGIOGRAPHY OF THE PERSISTENT TRIGEMINAL ARTERY VARIANT

Objective: To evaluate the MR angiographic findings of the persistent trigeminal artery variant (PTAV) and to discuss its clinical implicati ons. Materials and Methods: 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 arteriog raphy. In all cases, MR angiography was performed at 1.5 T. Results: M R angiography demonstrated the PTAVs as hyperintense structures origin ating from the precavernous portion of the internal carotid artery, ru nning within or very close to the Meckel cave and near the trigeminal nerve root, and reaching the posterior fossa (cerebellar arteries) wit hout joining the basilar artery, Spin echo imaging failed to demonstra te the PTAVs. Conclusion: Source imaging of MR angiography helped demo nstrate PTAV and its adjacent structure. Knowledge of the presence and course of this anomalous vessel is useful for various treatment strat egies.