COLOR DOPPLER TWINKLING ARTIFACT IN HYPERECHOIC REGIONS

PURPOSE: To investigate a new color Doppler ultrasound (US) artifact t hat manifested as a rapidly changing mixture of red and blue behind a strongly reflecting structure. MATERIALS AND METHODS: In 140 consecuti ve patients with parenchymal. calcifications seen at US, the presence of a color signal was assessed in calcified areas relative to adjacent noncalcified tissue. The artifact, called the twinkling color artifac t was simulated with various strongly reflecting structures immersed i n still water. RESULTS: The artifact was found in 42 parenchymal calci fications. In vitro experiments showed that the twinkling artifact was present in granular structures, whereas no color signal was noted in smooth surfaces. The ''twinkling sign'' appeared to be generated by a strongly reflecting medium composed of individual reflectors. CONCLUSI ON: The presence of a color signal close to calcifications should be i nterpreted with caution, and a flow spectrum should always be recorded to eliminate the twinkling artifact.