In vivo quantification of image enhancement and circulation kinetics for phase change perfluorocarbon agents using custom pulse sequences

Few investigations have been published demonstrating the in vivo contrast characteristics of phase-change perfluorocarbon droplets. In this study, we examine the properties of low boiling point nanoscale droplets compared to microbubbles with respect to image enhancement and circulation time. To accomplish this, we develop a custom pulse sequence to vaporize and image droplets using the Verasonics research platform. Results show that droplets can produce similar contrast compared to microbubbles, and can circulate for significantly longer than microbubbles, depending on formulation. Finally, this study demonstrates a novel concept in contrast-enhanced ultrasound: capture of droplet-generated contrast wash-out in the target organ.