Feasibility study of high intensity focused ultrasound combining with ultrasound contrast agent to damage hepatic VX2 tumors in rabbits

Objective To assess the feasibility of ultrasound microbubble contrast agent combining with high intensity focused ultrasound to treat hepatic VX2 tumors in rabbits. Methods Thirty rabbits borne VX2 tumors were randomly averagely assigned into two groups. One group accepted purely high intensity focused ultrasound (HIFU) irradiation, and the other group accepted treatment by HIFU combined with ultrasound contrast agent. Results Duration of purely high intensity focused ultrasound therapy tumors was much longer than that of enhanced high intensity focused ultrasound group, but smaller damaged volumes. Conclusion It was feasible to enhance HIFU therapy with microbubble contrast agent. The energy efficiency factor (EEF) can be changed and decreased by actively changing tissue structure and its function.