A study of pressure-dependent attenuation in ultrasound contrast imaging

The attenuation of ultrasound by microbubble contrast agents is dependent on acoustic pressure. While many previous studies have modelled this acoustic behaviour in individual single bubbles, this paper investigates the pressure-dependence of attenuation by considering a bulk volume of bubbles combined with other linear attenuators. A new pressure-dependent attenuation model for a volume of different attenuators is proposed. In this model the effect of the attenuation on the ultrasound propagation is considered. The new model was validated using experimental measurements of the ultrasound contrast agent Sonovue™. It is shown that the measurements fit to the proposed model. It is also shown that at low acoustic pressures with little bubble destruction, attenuation of Sonovue™, measured in dB, is linearly related to both its concentration and the insonating acoustic pressure.