An Important Clue in the Sonographic Diagnosis of Internal Carotid
Artery Agenesis: Ipsilateral Common Carotid Artery Hypoplasia
Figure 3
(a) After contrast injection to the left common carotid artery, the presumed (but absent) left ICA tract does not reveal any filling, while the left ECA and its branches are clearly visible. (b) At this Towne projection image, the filling of the left anterior cerebral and medial arteries via the patent anterior communicating artery is seen. (c) At this right lateral projection, vascular fillings of the left hemicranium with contrast via the posterior communicating artery following the injection of the vertebral artery are seen. (d) At arcus aortography, the right vertebral artery is seen as the first branch stemming from the aortic arch. The left common carotid artery caliber is substantially decreased. The left vertebral and subclavian arteries look tortuous.
