fig 3.

Partial occlusion of ICA.

A, Lateral angiogram of right ICA artery shows occlusion of cervical and petrous segments and filling of the carotid siphon and supraclinoid segments (arrow) via collateral flow from ophthalmic artery.

B, CTA with Mastercut MPR shows two-frame window. Right frame contains MIP image, and left frame contains a reformatted curved plane (panoramic image) related to white cut line drawn on the MIP image. Start of cut line is marked with asterisk. Owing to reconstruction artifacts caused by vessel contact with bone (especially with petrous segment of carotid artery), vasculature cannot be assessed reliably with MIP images (arrows) alone. The MasterCut MPR image clearly depicts occluded (broad arrows) and open (thin arrows) segments with the same accuracy as the arteriogram.

C, CTA with MIP (right) and MasterCut MPR (left) of normal left ICA. Start of the cut line (asterisk) is shown.