There are tortuosity and kinking of the proximal left subclavian artery, brachiocephalic artery and proximal right common carotid artery. Atheromatous mixed plaques promote stenosis in the transition of common carotid arteries to the internal carotid arteries:
Right ICA stenosis = ~50%
Left ICA stenosis = >80%
Right vertebral artery is dominant with left vertebral artery terminating as left PICA (hypoplastic).