New adaptive clutter rejection based on spectral analysis in ultrasound color-flow imaging

We have developed a new adaptive clutter rejection technique where an optimum clutter filter is dynamically selected according to the varying clutter characteristics in ultrasound color-flow imaging. The selection criteria have been established based on spectral analysis of an estimate of the temporal autocorrelation matrix of clutter signals. The performance of the clutter rejection techniques is quantified from a wall-less flow phantom and in vivo studies. The in vivo color-flow images obtained from hepatic veins are presented to illustrate the potential of the proposed adaptive clutter rejection technique. In hepatic vein in vivo studies, we obtained an average gain of 4.1 dB and 3.4 dB in flow signal-to-clutter-ratio compared to the conventional and down-mixing methods, respectively.