Fig. 1.

a–d Common dispositions of the aortic arch. It is important to appreciate that a continuum exists in terms of variation patterns. For example, the right VA can originate in its classic location (a) and anywhere along the more proximal subclavian artery (d) to the fully separate direct origin from the aortic arch (c). The same applies for the “bovine arch” variant (b) where the left CCA can appear to share a common origin with the brachiocephalic artery (truncus bicaroticus) rather than from the brachiocephalic artery itself. ^© neuroangio.org, used with permission here and for all subsequent figures.