Congenital Absence of the Internal Carotid Artery – a Rare Case Identified by Ultrasound

Absence or hypoplasia of one or both internal carotid arteries is a rare condition that may remain asymptomatic and is usually diagnosed incidentally while investigating for other pathology. Knowledge of the anomaly should prompt further clinical evaluation, as it is associated with a high incidence of cerebral aneurysms. This case describes the use of ultrasound in the diagnosis of the condition, confirmed by magnetic resonance imaging, in a female patient with symptoms suggestive of transient ischaemic attacks.