TY - JOUR T1 - Segmental Agenesis of the Internal Carotid Artery Distal to the Posterior Communicating Artery Leading to the Definition of a New Embryologic Segment JF - American Journal of Neuroradiology JO - Am. J. Neuroradiol. SP - 1189 LP - 1193 VL - 25 IS - 7 AU - Philippe Gailloud AU - Richard E. Clatterbuck AU - Jean H.D. Fasel AU - Rafael J. Tamargo AU - Kieran J. Murphy Y1 - 2004/08/01 UR - http://www.ajnr.org/content/25/7/1189.abstract N2 - Summary: We report a case of segmental agenesis of the right internal carotid artery (ICA) in a 53-year-old woman, associated with a saccular aneurysm of the left anterior cerebral artery (A1 segment) presenting with a right hemispheric transient ischemic attack. The agenetic segment was located distal to the origin of the posterior communicating artery (PComA), as documented both angiographically and by direct surgical inspection. This observation suggests the existence of a previously unrecognized embryologic segment of the ICA, located between the PComA origin and the terminal bifurcation of the ICA into the anterior and middle cerebral arteries. ER -