High speed imaging of shockwave‐induced dynamics of cavitation bubbles and vessel wall.

Abstract

High speed optical imaging under a microscope (high speed photomicrography) was used to observe shockwave‐induced bubble dynamics and bubble‐induced vascular dynamics. Ultrasound contrast agent microbubbles, serving as cavitation nuclei, were injected into the vessels of ex vivo rat mesentery. The bubbles were then insonated by focused shock wave pulses with peak positive pressures of 42 MPa and peak negative pressures of 10 MPa, generated by an electromagnetic shockwave source (Storz Duolith). The recorded images were analyzed to obtain bubble radius‐time curves, vessel wall displacement, as well as their corresponding velocities. In general, bubble dynamics induces vessel distention (outward displacement of vessel wall) and invagination (displacement of vessel wall into the lumen). Comparisons of shockwave‐induced dynamics with HIFU‐induced dynamics will also be presented. [Work supported by NIH EB000350 and AR053652.]