This patient has total occlusion of the right internal carotid artery and hemodynamically significant stenoses in the external carotid artery and left internal carotid.
A ≥70% ICA stenosis but less than near occlusion of the ICA is diagnosed when the ICA PSV is greater than 230 cm/sec, and visible plaque and luminal narrowing are seen at grey-scale and color Doppler US. Additional criteria include ICA/CCA PSV ratio > 4 and ICA EDV > 100 cm/sec. The higher the Doppler parameter lies above the threshold of 230 cm/sec, the greater the likelihood of severe disease 1.
See also:
Carotid artery stenosis: ultrasound criteria