The dynamics of cavitation bubble clouds in high-intensity focused ultrasound field observed by high-speed photography

High-speed photography is being considered as an effective technique to record the transient phenomena in medical field. This presentation summarizes our previous work of using high-speed photography in the observation of cavitation bubble clouds generated in high-intensity focused ultrasound (HIFU) field, aiming at the better understanding of the cavitation mechanism during the medical application of HIFU. A high-speed photography system synchronized with HIFU emission facilities was built up, and using this system we have investigated the dynamics of cavitation bubble clouds (i) in the whole HIFU free field; (ii) in the focal region of HIFU free field; and (iii) near the tissue surface in HIFU field. The spatial-temporal evolution of the bubble cloud and the characteristics of bubble cloud structures as well as the possible explanations to the recorded phenomena are reviewed. All the results we got elucidated that the highspeed camera is a potent tool to detect the cavitation phenomena in HIFU field.