Figure 1.

(A) VRT image of a carotid CT angiography; (B) VRT illustration of the cervical ICA measurement landmarks (carotid bulb—C1a; post-bulbar dilation—C1b; at the middle of C1—C1c; and below its entrance into carotid foramen—C1d) and representation of the carotid foramen position (yellow line); (C) oblique MIP image demonstrating set measurement points in the iICA (C2–C7). Abbreviations: CCA—common carotid artery; ICA—internal carotid artery; eICA—extracranial (cervical) part of ICA; iICA—intracranial part of ICA; ECA—external carotid artery; VRT—volume rendering technique; MIP—maximum intensity projection.