Weighting the Passive Acoustic Mapping Technique with the Phase Coherence Factor for Passive Ultrasound Imaging of Ultrasound-Induced Cavitation
Résumé
Ultrasound cavitation is currently being explored for low-invasive therapy techniques applied to a wide panel of pathologies. Because of the random behavior of cavitation, a real-time spatial monitoring system may be required. For this purpose, ultrasound passive imaging techniques have been recently investigated. In particular, the passive acoustic mapping (PAM) beamforming method enables the reconstruction of cavitation activity maps by beamforming acoustic signals passively recorded by an array transducer. In this paper, an optimized version of PAM, passive acoustic mapping weighted with a phase coherence factor (PAM-PCF), is considered. A general validation process is developed including simulations on a point source and experiments on a wire. Furthermore, using a focused regulated ultrasound-induced cavitation generator, reproducible cavitation experiments are conducted in water and in agar gel. The spatial behavior of a bubble cavitation cloud is determined using the PAM-PCF beamforming method to localize the focal cavitation point in two perpendicular imaging planes.