Image Based Simulation for Liver Tumor Ablation by Focused Ultrasound

The present computational model is aimed at predicting the temperature field in a region of the hepatic parenchyma with a cancer resulting from applied high-intensity focused ultrasounds (HIFU) for thermal ablation of the tumor in a patient-specific geometry. The three-dimensional (3D) acoustic–thermal–hydrodynamic coupling model computes the pressure, temperature, and blood velocity fields expressed by the nonlinear Westervelt equation with relaxation effects and bioheat equations in both the hepatic parenchyma and blood vessels (sink). The classical nonlinear Navier–Stokes equations related to mass and momentum conservation in large hepatic blood vessels are employed both for convective cooling and acoustic streaming. This 3D three-field coupling demonstrates that both convective cooling and acoustic streaming change the temperature considerably near large blood vessels. In addition, acoustic streaming cannot be neglected due to resulting velocity magnitude and blood redistribution between different branches. The results presented in the current work can be further used to construct a surgical planning platform.