High Frame-rate Coherent Diverging Wave Imaging with 2-D Motion Compensation

The use of diverging ultrasound waves provides enhanced temporal resolution for cardiac function assessment. However, current image formation techniques using coherent summation, are susceptible to motion artifacts. In this study, we used correlation based 2D motion estimation to perform motion compensation for coherent diverging wave imaging. The accuracy of this motion estimation method was evaluated with Field II simulations, giving root-mean-square velocity errors of 5.9% 0.2% and 19.5% 0.4% in the axial and lateral directions relative to the maximum velocity of 62.8 cm/s. The results of motion estimation were further processed to render the vector flow map and interpret the motion pattern of the disk. Improvement of the B-mode image quality of a 10 cm in vitro tissue mimicking rotating disk was also demonstrated by removing dark imaging artifacts in the compound image.