Reconstruction of thermal field in target tissue during the therapy of high intensity focused ultrasound

Abstract

High intensity focused ultrasound (HIFU) is a minimally invasive medical procedure, obtaining the transient temperature field of the target tissue is a key to study HIFU ablation. In this work, an inverse heat transfer scheme is proposed to investigate thermal effect of HIFU and further reconstruct the transient temperature field of the target tissue. In the inverse scheme, a prediction model is established between the measured temperature and heat source in the target tissue. Then, based on the prediction model, a model predictive inverse scheme is established to estimate heat source induced by HIFU in the target tissue. Finally, the inversed heat source is used to solve biological heat transfer equation to reconstruct temperature distribution in the target tissue of HIFU ablation. Numerical experiments are performed to study the effects of the form of heat source, the number of future time steps and measured error on the inverse results. The results have shown that the inverse scheme can significantly reduce the sensitivity of the inverse results on measurement noise, and the temperature distribution in the target tissue can be obtained by the inverse scheme, which provides theoretical guidance for treatment planning and efficacy evaluation of HIFU.