Ring Array Passive Acoustic Mapping Using Hybrid Heterogeneous Angular Spectrum Method

Passive acoustic mapping (PAM) using a ring array facilitates high-resolution panoramic monitoring of cavitation activities in human breast. While the heterogeneous angular spectrum method has been developed for fast PAM reconstruction using planar arrays, it is not directly applicable in ring arrays. In this work, we combine the Rayleigh-Sommerfeld diffraction integral and the angular spectrum method for fast panoramic PAM with high resolution in heterogeneous medium. We evaluated the spatial resolution of the hybrid method with ring array in simulated experiments. Bubble clouds localization ability of the proposed method was assessed by imaging 9 tubes containing randomly distributed bubbles in the tumor of a human breast phantom with heterogeneous speed of sound (SoS) and compared with time-domain (TD-) and frequency-domain (FD-) “delay and sum” (DAS) methods. Results show that the proposed method can provide high resolution panoramic PAM images in the heterogeneous human breast phantom with more than 8 times speed-up compared to TD-DAS and FD-DAS algorithms.