Investigation of the effects of microbubble shell disruption on population scattering and implications for modeling contrast agent behavior.

In a previous study, quantitative measurement of nonlinear scattering revealed some quantitative discrepancies with a model for ultrasound scattering by a population ensemble of microbubbles. This study is designed to investigate the effect of the shell on single-pulse scattering by a population of contrast microbubbles. Nonlinear scattering was measured shortly (15 micros) after exposure to a previous ultrasound pulse with variable intensity. The short time delay eliminated the influence of gas diffusion and focused the study on the consequence of ultrasound exposure. The results suggest that single-pulse scattering is dependent on the disruption properties of the bubble shell and confirm the significance of the shell properties.