Detection of high intensity focused ultrasound induced cavitation activity in liver tissue

Abstract

Microbubbles are known to be able to enhance the thermal effect of ultrasound. In HIFU procedure, microbubbles can be generated when the peak negative pressure is large enough or the temperature exceeds the boiling point. In this work, cavitation activities in various exposure protocols with equal total acoustic energy but variable focus pressure and variable duty cycle were monitored in vitro. A 10 MHz focused passive cavitation detector transducer was used to capture acoustic emissions emanated from liver tissue exposed to 1.12 MHz HIFU pulses, while the focus temperature was recorded. The inertial cavitation dose (ICD) was calculated to analyze the cavitation activity qualitatively. The correlations of cavitation activity, temperature and focus pressure were discussed. [This work is supported by the National Basic Research Program 973 (Grant No. 2011CB707900) from Ministry of Science and Technology, China, National Natural Science Foundation of China (11174141), and the Fundamental Research Funds for t...