P4D-1 Development of a Finite Element Model of Ultrasound Contrast Agent

Experimental studies of ultrasound contrast agents (UCAs) indicate that adherent UCAs are acoustically differentiable from free-floating UCAs. This study aims to create a numerical model that can be used to predict how attachment affects UCA behavior. COMSOL Multiphysicstrade is used to compute the pressure field scattered by spherical objects. At first, a simple gas core microbubble is considered. Then an elastic shell is incorporated into the model: the acoustic phenomenon is coupled to the solid shell behavior through boundary conditions at the surface of the shell. The finite element model is able to predict the resonance of these objects. The gas core microbubble response is in good agreement with Minnaert´s theory. The results obtained for the encapsulated microbubble have been compared with those obtained with analytical models. These first attempts on free-floating UCAs being satisfactory, future works will focus on adherent UCAs.