Lipid encapsulated microbubbles are used as contrast agents in ultrasound imaging. Currently available commercially made contrast agents have a polydisperse size distribution. It has been hypothesised that improved imaging sensitivity could be achieved with a uniform microbubble radius.
Working with the lab of Abraham Lee at UC Irvine, The Dayton lab has recently developed microfluidics technology to produce contrast agents with a nearly monodisperse distribution. In this paper, the authors analyse echo responses from individual microbubbles from monodisperse populations in order to establish the relationship between scattered echo, microbubble radius and excitation frequency. Simulations of bubble response from a modified Rayleigh–Plesset type model corroborate experimental data. Results indicate that microbubble echo response can be greatly increased by optimal combinations of microbubble radius and acoustic excitation frequency. These results may have a significant impact in the formulation of contrast agents to improve ultrasonic sensitivity.