The carotid ghost. A color Doppler ultrasound duplication artifact.

Color Doppler ultrasound examinations of the neck frequently demonstrate an artifactual region of color assignment deep to the common carotid artery that simulates blood flow in deep cervical arteries. Based on analysis of imaging performed on 10 normal volunteers, it was shown that the pulsed Doppler waveform originating from the artifact was identical to that of the common carotid artery. It was also shown that the artifact was always located deep to the common carotid artery regardless of location and positioning of the transducer. In vitro modeling using a flow phantom confirmed that the appearance was artifactual in nature. The mechanism of production most likely is related to a mirroring phenomenon at the deep wall of the common carotid artery.