Agenesis of an internal carotid artery: angiographic, tomographic and computed tomographic correlation.

Congenital absence of one internal carotid artery was found by angiography in a woman of 52 years who had subarachnoid hemorrhage. The absence of the bony carotid canal on the affected side substantiated the congenital nature of this rare vascular anomaly. We believe this to be the first report of absence of the bony carotid canal and the intracavernous portion of the internal carotid artery confirmed by computed tomography and cavernous sinography.