Objective     To comparatively evaluate the performance of vector flow imaging based on Doppler and speckle tracking (ST). Methods     Based on ultrafast ultrasound imaging technique with multi-angle plane wave transmission

vector flow imaging was performed using Doppler and ST methods

respectively. Performance of the 2 methods was assessed in simulation

phantom

and in vivo study. Results     For a simulated artery

the bias of the horizontal velocity component was 3.15% and 4.36% in Doppler and ST methods

respectively. The bias of vertical velocity component was 1.79% and 1.00%

respectively. The bias of the 2 methods was similar with each other. In the phantom experiment with the maximal velocity of 100 cm/s

the bias was -5.00 % and -5.28 %

respectively for the horizontal velocity component

and was 0.53 and 1.46 cm/s respectively for the vertical velocity component. Blood flow estimated with ST method had relatively larger bias

and the peak velocity appeared to be underestimated. In the in vivo experiments

estimated velocity in ST method was smaller than that in Doppler method. Conclusion     In simulation

both Doppler and ST methods can achieve considerably accurate vector flow measurements. In the phantom and in vivo studies

the estimated velocity in ST method was smaller than the velocity in Doppler method.