MIRROR-IMAGE ARTIFACTS OF COLOR DOPPLER IMAGES CAUSING MISINTERPRETATION IN CAROTID-ARTERY STENOSES

A knowledge of mirror image artifacts in color-coded duplex sonography is important as they can lead to diagnostic problems in the morpholog ic evaluation of stenoses and plaques. Mirror image artifacts were det ectable in stenosed vessels when strongly reflecting plaques on the wa ll of the vessel distant from the transducer head were insonated obliq uely. The artifacts were revealed in regions that were hypoechoic or a nechoic on B-mode scans. Depending on the angle of insonation and the surface structure of the plaque, the mirror image artifact could be li nked with the vessel lumen and thus imitate ulcerations or branches. T he artifact appeared in both the longitudinal and the transverse proje ctions and also occurred in the power Doppler and in pulsed Doppler so nographic modes. Mirror image artifacts with linkages to the vessel lu men that could result in a misinterpretation were seen in 2.5% of the stenosed vessels.