Transverse oscillations beamformer design for sector scan using back-propagation

Echocardiographic acquisition based on point spread function (PSF) with transverse oscillations (TO) has been shown to be an efficient image formation technique for improving the accuracy of motion estimation in the transverse direction (direction perpendicular to the propagation axis). To date, beamforming yielding TO has mainly been developed for acquisitions performed in linear geometry. However, one of the most important applications of motion estimation is cardiac imaging, which implies acquisition done in sectorial geometry. In this framework, this paper describes a new beamformer design method as well as the corresponding implementation allowing for transverse oscillations for sector scan. The proposed method uses a back-propagation (BP) approach. The performance of this beamformer is quantitatively evaluated through numerical simulations. In particular, we show that the obtained PSF are closer to the expected ones as compared to PSF obtained using the conventional Fraunhofer approximation and the associated Fourier relation.