Protrusion der Arteria carotis interna in den Sinus sphenoidalis

An additional

challenge for head and neck radiologists: anatomic variants posing a surgical risk – a pictorial review. Carotid canal variants. a Both canals protrude into the sphenoid sinus cavities; the bony wall is thinned on the right side (arrows). b Incomplete bony septa stem from the bony walls of the canals (arrows): during endoscopic surgery, such septa may act as a leverage and facilitate injury of the ICA