Lateral modulation of ultrasonic field by adaptive beamformer for motion estimation

Abstract

We are studying on measurement of tissue dynamics using very high-frame-rate ultrasound, which realizes a temporal resolution of over thousand Hertz. For measurement of tissue motion, the displacement of an object needs to be estimated using the received ultrasonic signal. However, the accuracy in lateral motion estimation is worse than that in axial motion estimation because the ultrasonic frequency in the lateral direction is lower than in the axial direction. To increase the ultrasonic frequency in the lateral direction, in the present study, the lateral modulation method [1] was used with adaptive beamforming. The basic experimental results using a phantom showed that the lateral modulation with adaptive beamforming realized a steeper lateral modulation than with the conventional lateral modulation method. [1] Jensen JA. A new method for estimation of velocity vectors. IEEE Trans. Ultrason.Ferroelectr. Freq. Control 1998;45:837-851.