Image-guided characterization of phase-shift droplets at pre-clinical frequencies in vitro and in vivo

Perfluorocarbon droplets that change state by acoustic and/or optical energy have been proposed for applications of medical ultrasound. Studies have primarily characterized droplet activation at frequencies common in human medicine. Motivation exists to design droplets for the higher frequencies used with superficial targets and small animal imaging. In this study, we measure the 20-40 MHz in vitro vaporization thresholds of size-selected phase-shift droplets on a pre-clinical platform and validate these measurements in vivo.