Accuracy evaluation of 3D velocity estimation by multi-frequency phase-sensitive motion estimator under various specifications of matrix array probe

The multi-frequency two-dimensional (2D) phase-sensitive motion estimator can estimate tissue motion without interpolation of ultrasonic echo signals. In real situations, biological tissues move three dimensionally and, thus, the 2D estimation may be affected by the movement in the elevational direction. In this study, we proposed a multi-frequency three-dimensional (3D) phase-sensitive motion estimator. The accuracy was verified with computer simulation and phantom experiments. In the simulation, the accuracies of the proposed 3D method with five types of matrix array probes were compared with the previous 2D method. The standard deviation in motion velocities estimated with a 32 × 8 matrix array probe was suppressed by 8.4% and 0.9% in lateral and vertical directions at (10, 10, 70) mm s^-1 (lateral, vertical, elevation). In phantom experiments, the proposed 3D method performed better than the 2D method. According to these results, the estimation accuracy was shown to be improved by considering the 3D movement.