Microbubble enhanced threshold reductions for tissue damage using high intensity ultrasound

We show that introducing gas filled microbubbles (ultrasound contrast agent) reduces the threshold intensity and requisite duration of a single ultrasound burst for producing observable tissue damage in canine kidneys in-situ. The presence of microbubble contrast agent enhances the effects of acoustic cavitation in producing tissue damage, especially when short duration ultrasound exposures are used. Unlike thermal ablation mechanisms, acoustic cavitation can destroy tissue without heating overlying tissue layers. By developing approaches using the benefits of microbubbles in reducing both threshold intensity and burst duration, acoustic cavitation may become a more predictable and effective mechanism for non-invasive ultrasound surgery.