Purpose: In high-intensity focused ultrasound (HIFU) comprising high-intensity burst ultrasound (triggering pulse) and medium-intensity continuous wave ultrasound (heating wave), optimizing the effects of the triggering pulse conditions on the coagulated volume may help to reduce treatment times.
Methods: HIFU combined with a triggering pulse was applied to chicken deep pectoral muscles. The acoustic power of the heating wave was set to 36, 54, or 72 W. Four different triggering pulse conditions were used: heating wave only; or pulse widths and pulse repetition frequencies of 30 μs and 1 kHz, 300 μs, and 100 Hz, or 3 ms and 10 Hz.
Results: Compared to the heating wave only condition, the coagulated volume was significantly larger under all conditions that included a triggering pulse. Significant differences were also observed in the ellipticity of the coagulated region between some conditions.
Conclusion: HIFU combined with a triggering pulse may play an important role in reducing treatment times.
Keywords: Cavitation bubbles; High-intensity focused ultrasound (HIFU); High-intensity therapeutic ultrasound (HITU).