Passive Acoustic Synthetic-Aperture Processing Techniques for High-Resolution Cavitation Mapping: From Pre-Clinic to Clinic (BBBO)

In this initial proof-of-concept study, we validated the passive acoustic synthetic-aperture (SA) processing techniques for PAM using pre-clinic and clinic data. Our simulation assessed SA PAM with single and multi-bubble cluster sources, followed by an in vivo comparison of the localization capability of SA PAM with conventional full-aperture time-exposure acoustics (TEA) using data from mouse and pediatric clinical trials. The simulation results demonstrate that when using four sub-apertures, spatio-temporal compounding (STc) in SA PAM improves spatial resolution by approximately 3-fold compared to the conventional method. Both the mouse and pediatric clinical results revealed that the disparity in microbubble activity localization (≈ 2 mm radial, 2° azimuthal) was within an acceptable range, while also showing a similar trend in spatial resolution enhancement. However, there was a trade-off in frame rate, which slowed by about 2-fold, and a 10 dB decrease in the signal-to-noise ratio (SNR). These findings illustrate the feasibility of SA PAM for high-precision localization in clinical monitoring, though further investigation into domain-specific implementations with alternative subaperture strategies could necessarily solve aforementioned trade-offs.