Discusssion

Color Duplex Evaluation of CCA Occlusion:

Occlusion is characterized by
1) Absence of color flow and Doppler flow signal within CCA
2) Lumen filled with echogenic material
3) Unilateral dampened flow within ipsilateral CCA. No flow or reverse flow proximal to occlusion
4) Reduced vessel size (chronic occlusion)

False positive occlusion occurs if the Doppler angle is 90 degree or when the artery is obscured by acoustic shadowing, poor image quality or a weak Doppler signal.