PITFALLS OF COLOR-CODED DUPLEX-SONOGRAPHY CAUSED BY COLOR DOPPLER ARTIFACTS

The practical application of colour-coded duplex sonography shows that physico-technical artifacts of colour Doppler imaging may not be obvi ous in all cases and can lead to misinterpretation. Slice-thickness ar tifacts are due to restricted transversal resolution, as in the B-mode , and may cause false negative results in vascular occlusions. Specifi c problems in creating and processing the colour flow image interfere with lateral resolution and lead to errors in the quantification of st enoses from the colour Doppler image. Mirror image artifacts produce p hantom pictures that can be easily identified as such in some cases, b ut may resemble recesses in the arterial wall in other cases. Phenomen a of sound shadowing resulting from the same reasons as in B-mode may lead to assume vascular occlusions in cases of long-range stenoses. Ar tifacts of the sonication angle in case of blood vessel tortuosity may lead to misdiagnosis of a non-existent retrograde flow. The artifacts mentioned do restrict the capacity of colour coded duplex sonography for localising flow in the ultrasound image. Users of the method shoul d therefore be familiar with these artifacts.