ABSTRACT
As the internal carotid artery(ICA) spans the cavernous sinus and supraclinoid segments, it assumes an S-shaped configuration on lateral view that is referred as the carotid siphon. The supraclinoid carotid artery begins where the artery emerges through the dural ring from the clinoidal segment, thereby forming the distal half of the siphon. The artery enters the subarachnoid space medial to the anterior clinoid process, just inferior to the optic nerve, and then pass posteriorly, and laterally to the side of the optic chiasm. The vessel then angles forward as it nears the anterior perforated substance at the medial end of Sylvian fissure, where it bifurcates into the anterior and middle cerebral arteries. The supraclinoid portion of the ICA can be divided into three segments: ophthalmic, communicating, and choroidal, based on the site of origin of the ophthalmic, posterior communicating, and anterior choroidal arteries, respectively.
Subject(s)
Arteries , Carotid Arteries , Carotid Artery, Internal , Cavernous Sinus , Choroid , Middle Cerebral Artery , Olfactory Pathways , Optic Chiasm , Optic Nerve , Subarachnoid SpaceABSTRACT
As the internal carotid artery(ICA) spans the cavernous sinus and supraclinoid segments, it assumes an S-shaped configuration on lateral view that is referred as the carotid siphon. The supraclinoid carotid artery begins where the artery emerges through the dural ring from the clinoidal segment, thereby forming the distal half of the siphon. The artery enters the subarachnoid space medial to the anterior clinoid process, just inferior to the optic nerve, and then pass posteriorly, and laterally to the side of the optic chiasm. The vessel then angles forward as it nears the anterior perforated substance at the medial end of Sylvian fissure, where it bifurcates into the anterior and middle cerebral arteries. The supraclinoid portion of the ICA can be divided into three segments: ophthalmic, communicating, and choroidal, based on the site of origin of the ophthalmic, posterior communicating, and anterior choroidal arteries, respectively.