Vector Flow Imaging by Plane Wave Speckle Tracking Based on Different Beamformers

Plane wave speckle tracking allows imaging the vector flow field in the region of interest at a very high frame rate at the cost of decreased image quality. Adaptive beamformers have been developed by researchers to improve image quality. In this study, the impact of beamformers on speckle tracking performance was investigated. Three typical coherence based beamformers were compared with the classical delay and sum beamformer. Utilizing ultrasound simulation, we constructed a synthetic wall-less vessel phantom where the scatterers moved according to a parabolic velocity profile. The results show that the mean bias of velocity estimation ranged from −5.6% to −6.4% and the mean standard deviation ranged from 2.2% to 2.8%, with the best accuracy achieved by coherence factor (CF) based speckle tracking. The angle estimation had high accuracy in all approaches, where the mean bias ranged from 0.1° to 0.5° and the mean standard deviation ranged from 0.5° to 2.3°. In conclusion, CF based speckle tracking performs best, which may help to improve the accuracy ofvelocity estimation in plane wave speckle tracking.