Extending Retrospective Encoding for Robust Recovery of the Multistatic Dataset

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control ferroelectrics, and frequency control, 2019-12, Vol.67 (5), p.943-956
• Main Authors: Ali, Rehman, Herickhoff, Carl D., Hyun, Dongwoon, Dahl, Jeremy J., Bottenus, Nick
• Format: Article
• Language: English
• ISSN: 0885-3010; 1525-8955
• DOI: 10.1109/TUFFC.2019.2961875

Robust recovery of multistatic synthetic aperture data from conventional ultrasound sequences can enable complete transmit-and-receive focusing at all points in the field-of-view without the drawbacks of virtual-source synthetic aperture, and further enables more advanced imaging applications such as backscatter coherence, sound speed estimation, and phase aberration correction. Recovery of the multistatic dataset has previously been demonstrated on a steered transmit sequence for phased-arrays using an adjoint-based method. We introduce two methods to improve the accuracy of the multistatic dataset. We first modify the original technique used for steered transmit sequences by applying a ramp filter to compensate for the nonuniform frequency scaling introduced by the adjoint-based method. Then we present a regularized inversion technique that allows additional aperture specification and is intended to work for both steered transmit and walking aperture sequences. The ramp-filtered adjoint and regularized inversion techniques, respectively, improve the correlation of the recovered signal with the ground-truth from 0.9404 to 0.9774 and 0.9894 in steered transmit sequences, and 0.4610 to 0.4733 and 0.9936 in walking aperture sequences.