Background: Our aim was to observe ultrasound-induced intravascular microbubble destruction in vivo and to characterize any resultant bioeffects.
Methods and results: Intravital microscopy was used to visualize the spinotrapezius muscle in 15 rats during ultrasound delivery. Microbubble destruction during ultrasound exposure caused rupture of < or = 7-microm microvessels (mostly capillaries) and the production of nonviable cells in adjacent tissue. The number of microvessels ruptured and cells damaged correlated linearly (P<0.001) with the amount of ultrasound energy delivered.
Conclusions: Microbubbles can be destroyed by ultrasound, resulting in a bioeffect that could be used for local drug delivery, angiogenesis, and vascular remodeling, or for tumor destruction.