Title:Phase-Change Contrast Agents for Imaging and Therapy
Volume: 18
Issue: 15
Author(s): Paul S. Sheeran and Paul A.Dayton
Affiliation:
Keywords:
Ultrasound, contrast agent, phase-change, acoustic droplet vaporization, perfluorocarbon, microbubble, drug delivery, diagnostic
imaging
Abstract: Phase-change contrast agents (PCCAs) for ultrasound-based applications have resulted in novel ways of approaching diagnostic
and therapeutic techniques beyond what is possible with microbubble contrast agents and liquid emulsions. When subjected to sufficient
pressures delivered by an ultrasound transducer, stabilized droplets undergo a phase-transition to the gaseous state and a volumetric
expansion occurs. This phenomenon, termed acoustic droplet vaporization, has been proposed as a means to address a number of in vivo
applications at the microscale and nanoscale. In this review, the history of PCCAs, physical mechanisms involved, and proposed applications
are discussed with a summary of studies demonstrated in vivo. Factors that influence the design of PCCAs are discussed, as well as
the need for future studies to characterize potential bioeffects for administration in humans and optimization of ultrasound parameters.
