Experimental Investigation of Relationship between Coagulation Size and Estimated Distribution of HIFU Heat Source from Displacement Distribution by Acoustic Radiation Force Imaging

Accurate estimation of the ultrasonic heat source in advance of therapeutic ultrasound exposure is important to increase the safety and efficacy of high-intensity focused ultrasound (HIFU) treatment. Acoustic radiation force imaging using a HIFU short burst is expected as a procedure for such estimation from the distribution of tissue displacement. In this study, the relationship between the coagulation size and the distribution of the displacement measured by the technique was experimentally investigated by varying the depth of HIFU focal point from the surface of the target tissue and the HIFU exposure power. The result showed that the same amount of the displacement provided almost the same size of the coagulation. It suggests that the estimation method has a potential to enable the in-situ adjustment of HIFU power for appropriate treatment.