Comparison of ultrasonic motion estimators for vascular applications

Abstract

One-dimensional (1D) motion estimators based on a phase shift of an ultrasonic echo signal have been used to estimate the axial strain of the artery. However, the lateral motion induced by the heartbeat cannot be neglected. Therefore, we proposed a two-dimensional (2D) phase-sensitive motion estimator previously. In this study, simulation experiments were performed to compare the accuracy of the 1D, 2D phase-sensitive, and speckle tracking methods. Furthermore, those three methods were applied to data obtained from a common carotid artery. The 2D phase-sensitive method showed the best accuracy among three, bias errors of 0.5% and standard deviations of 6.6% were obtained with respect to the estimated axial velocities in the simulation experiments. Meanwhile, the speckle tracking showed the best accuracy on the axial strain estimation, bias errors of 4.4% and standard deviations of 8.5% were obtained. In conclusion, the accuracy in the estimation of motion and strain was improved by considering the lateral motion.