Measuring Viscoelastic Properties with in-situ Ultrasonically Induced Microbubbles

A preliminary study on new bubble-mediated microenvironment viscoelastic imaging technique using our novel contrast agent phase-change nano droplet is performed. Apparent difference is observed among acoustic signals obtained from gel phantoms with difference in elastic properties at the timing of phase change induction. In particular, frequency of responding motion to impulse (f(res)) exhibited high correlation with gel's elastic properties between Young's modulus of 10 - 39 kPa. Furthermore, other parameters such as magnitude of phase change are influenced by change in gel's polyacrylamide concentration, possibly due to change in both elasticity and viscosity. These results suggest that PCND is a promising tool for characterizing microenvironment tissue viscoelastic properties.