Head and neck – Case 16

A : Petrous segment (C2) of internal carotid artery
B : Cavernous segment (C4) of internal carotid artery
C : Middle cerebral artery
D : Anterior cerebral artery
E : Pericallosal artery

Remarks :
1. Lateral oblique view of digital subtraction angiogram of internal carotid artery.
2. Unlike CTA and MRA, contrast is injected into one artery at a time, so the anterior and posterior circulation are not shown at the same time
3. This is internal carotid artery as it reveals the typical features of various segments :
a) Cervical segment (C1) : Travels vertically upwards along the neck
b) Petrous segment (C2) : Travels anteromedially ( i.e. appeared as horizontally in both lateral and AP view ) inside petrous part of temporal bone
c) Lacerum segment (C3) : Travels vertically upwards until reaching cavernous sinus
d) Cavernous segment (C4) : Travels anterosuperiorly as it prepares cerebral segment to give off ophthalmic artery by approaching near the orbit
4. Anterior cerebral artery eventually becomes branches bending around genus of corpus callosum ( i.e. the pericallosal and callosomarginal artery )
5. Middle cerebral artery is not misinterpreted as posterior cerebral artery in this DSA because it comes from the internal carotid artery, but not the basilar artery