Gaussian-integration technique to predict backscatter characteristics from ultrasound contrast agents

Many new ultrasound imaging modalities, such as second harmonic, subharmonic and ultraharmonic detection techniques, that take advantage of the nonlinear characteristics of contrast microbubbles have emerged recently. Control and prediction of the occurrence and amplitude of the nonlinear emissions from ultrasound contrast microbubbles are important for the further development of these techniques. A Gaussian-integration (GI) method for predicting the nonlinear emission signals from microbubbles with wide size distribution is presented. The GI method is validated preliminarily by the nonlinear emissions from Levovist® and ST68® contrast microbubbles, with good results. This method may provide a computationally inexpensive means of examining the backscatter spectrum from multiple bubbles, and could be used as an inverse method in predicting bubble characteristics from backscatter spectra.