Changing Acoustic Environment In Tissue With Microbubble For Enhancing High Intensity Focused Ultrasound Therapy Efficacy: An Initial Study

Background and Objectives High Intensity Focused Ultrasound (HIFU) utilized hyperacoustic focalization and tissular penetrability to ensure ultrasound energy depositing in the focus. It was non-invasive ablating tumor surgery. HIFU has been succeeded in treating hepatoma. When the hepatic tumor was large in volume or deep in postion, the attenuation of sound was obvious with the increase of transmission distance, which induced insufficient energy deposition in the focus. Because malignant tumor was rich in blood supply, the cooling effect of perfusion may limit the temperature rising. Moreover, different acoustic characteristics of different target tissues caused the disparity of energy deposition. Accordingly, HIFU therapy efficiency decreased, the exposure time increased, and patients encountered the risk. Certainly, it was hard to ensure the efficacy and safety of HIFU therapy. Acoustic environment in tissue (AET) indicated the change of structure, function and acoustic...