Effect of pulse repetition frequency on microcalcification detection in color flow imaging

The twinkling sign is a phenomenon involving rapidly alternating color pixels behind a stationary strongly reflecting medium where an acoustic shadow is expected in the Doppler mode. However, the mechanism of the occurrence of such a sign is not yet clarified. In this study, to clarify the mechanism, we investigated effect of pulse repetition frequency (PRF) on echo signals from a glass bead (diameter 973 µm) in a soft-tissue-mimicking phantom, and observed the appearance pattern of the twinkling sign of the same glass bead. It was observed that the variance of the IQ signal and the appearance frequency of the twinkling sign decreased when PRF increased.