Effects of acoustic nonlinearity and blood flow cooling during HIFU treatment

Abstract

The present study is aimed at predicting liver tumor temperature during a high-intensity focused ultrasound (HIFU) thermal ablation in a patient-specific liver geometry. The model comprises the nonlinear Westervelt equation and bioheat equations in liver and blood vessel. The nonlinear hemodynamic equations are also taken into account with the convected cooling and acoustic streaming effects being taken into account. We found from this three-dimensional three-field coupling study that in large blood vessel both convective cooling and acoustic streaming can change the temperature near blood vessel. Acoustic streaming velocity magnitude can be 4-5 times larger than the blood vessel velocity. Nonlinear wave propagation effects lead to the enhanced heating in the focal area and help to ablate tumor close to the blood vessel wall. © 2012 American Institute of Physics.