Segment Description Notes
C1 (Cervical) CCA bifurcation to entrance of carotid canal
C2 (Petrous) …to posterior edge of formaen lacerum
C3 (Lacerum) …to superior margin of petrolingual ligament
C4 (Cavernous) …to proximal dural ring (anterior clinoid process)
C5 (Clinoid) …to distal dural ring

(cavernous sinus roof)

C6 (Ophthalmic) … to just proximal to the origin of PComm
C7 (Communicating) … to ICA bifurcation



Bouthillier, A., et al. (1996). “Segments of the internal carotid artery: a new classification.” Neurosurgery 38(3): 425 – 432.