Ultrasound examination showing CCA occlusion with patent distal vessels. (a) Colour mode examination: no flow in the right common carotid artery, and the vessel lumen is filled with thrombotic material. (b) Colour mode examination of carotid bifurcation: reversed flow in the ECA, anterograde flow in the ICA. (c) Duplex mode examination: anterograde flow in the ICA. (d) Duplex mode examination: retrograde flow in the ECA.