Two Rare Variations; Persistent Trigeminal Artery and Hypoplasia of the A1 Segment of the Anterior Cerebral Artery

The trigeminal artery, which is one of the major carotid-basilar anastomoses in the fetal period, regresses with the development of the posterior circulation in the prenatal period. In rare cases, when this regression does not occur but persists, it is called persistent trigeminal artery (PTA). Because of the association of the persistent trigeminal artery with many other cerebral vascular pathologies, it is of vital importance to identify it and know its imaging characteristics, especially in cases where vascular surgery or interventional procedures are planned. We report a case with PTA and hypoplasia of the A1 segment of the anterior cerebral artery (ACA) as an associated vascular anomaly. Magnetic resonance angiography (MRA) is a non-invasive method for the detection of PTA and other vascular anomalies.