Dual Aperture Motion Compensation (DAMoCo)

One of the issues affecting motion compensation schemes in ultrasound imaging is sidelobe re-alignment, a cause of potentially significant image degradation. In this study, we propose a method to address this problem based on tracking the motion between frames that have been beamformed with different receive apodizations. As a result, the motion estimator is able to track the motion of only the mainlobe signal. Subsequently, the frames with the same receive apodization are motion compensated according to the Dual Aperture (DA) motion estimate (DAMoCo). Thus, only mainlobe signals are correctly rephased and coherently summed. This technique can be used in coherent compounding schemes where the point spread function's sidelobes tilt from subframe to subframe, as well as in adaptive coherent persistence modalities without sidelobe tilt, to further improve image quality by suppressing sidelobe signals. This technique was applied to diverging wave simulation data as well as in diverging wave and focused transmit in vivo cardiac data. In both cases, DAMoCo was found to be capable of suppressing sidelobes, thus improving contrast. However, its effects were milder for the in vivo datasets.