Correlation search method with third-order statistics for computing velocities from ultrasound images

The correlation search method yields velocity information by tracking scatter patterns between ultrasound image frames. The displacement vector between a target region and the best-correlated search region indicates the magnitude and direction of the interframe motion of that particular region. However, if the noise sources in the target region and the search region are correlated Gaussian, then the cross-correlation technique fails to work well because it estimates the cross correlation of both signals and noises. A correlation search method is developed to seek the best-correlated third-order statistics between a target and the search region to suppress the effect of correlated Gaussian noise sources. The method yields better estimations of velocity than does the conventional cross-correlation method.