Potential bioeffects of ultrasonic destruction of microbubble contrast agents.

t is well known that microbubble destruction can occur uring contrast echocardiography, primarily by acoustic avitation (1). The propensity of microbubbles to undergo his process when exposed to ultrasound depends on physcal properties of both the bubbles themselves and the ltrasound beam. Higher rarefactional peak amplitude (a easure of ultrasonic acoustic power) and lower frequencies ause greater microbubble destruction (1–3). Thickness, ompressibility, and elasticity of the microbubble shell are mportant factors in their susceptibility to ultrasoundediated destruction (4). The ability to destroy microubbles has useful clinical applications, allowing the quanification of myocardial perfusion using replenishment urves (5). Also, we and others (6) have begun to investigate his attribute of microbubbles as a method for targeting ene or drug delivery.