Colour Doppler imaging of an ascending pharyngeal artery arising from the internal carotid artery.

We present two cases of an extracranial collateral of the internal carotid artery. The descriptions include Doppler recording and colour flow-mapping. The report underlines the epidemiological, embryological and anatomic features (including Doppler characteristics) of the variant, with a view to helping sonographers whenever the carotid examination proves difficult.