Effect of shear wave propagation on estimation of heating distribution by high-intensity focused ultrasound using acoustic radiation force imaging

In a high-intensity focused ultrasound (HIFU) treatment, to predict a HIFU heat source is important for the safety and efficiency. Acoustic radiation force impulse imaging using a HIFU burst is known as a method for the prediction from the distribution of the tissue displacement in a homogeneous tissue. However, the distribution induced by HIFU radiation force expands as the shear wave propagates. In this study, the effect of the shear wave propagation on the estimation of the heat source distribution was investigated by changing the burst duration and intensity of HIFU. The results showed that a shorter HIFU burst provided the higher accuracy of the prediction, improving the spatial resolution. It is concluded that the estimation method has the potential to estimate in a wide range of HIFU energy and requires one to obtain the distribution of displacements immediately after the start of HIFU burst exposure. (C) 2020 The Japan Society of Applied Physics