The Acoustic Nonlinearity of a Single Ultrasound Contrast Agent Microbubble

Ultrasound contrast harmonic imaging techniques based on shelled microbubbles´ nonlinear oscillation have been used in clinical diagnosis successfully, however a parameter characterizing the nonlinear scattering properties of a single bubble has not been found yet. In this study, based on Church Hoff equation describing the dynamics of an encapsulated microbubble, the nonlinearity parameter of a microbubble was derived from the ratio of the second harmonic to the fundamental harmonic. The nonlinearity parameter can be used to quantify and design the nonlinearity of a microbubble.