Shockwaves During Cavitation Creation with Sonosensitizer

Japanese Journal of Applied Physics, Volume 53, Number 7S

Author: Jun Yasuda, Takuya Miyashita, Shin Yoshizawa and Shin-ichiro Umemura, Graduate School of Engineering and Second Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan

”Acoustic cavitation bubbles are microbubbles generated by the highly negative pressure of ultrasound. They are known to enhance the thermal bioeffect of high-intensity focused ultrasound (HIFU) treatment. Other than the use of the thermal bioeffect, sonodynamic treatment using the sonochemical bioeffect of ultrasound has been proposed. In sonodynamic treatment, a sonosensitizer is activated through the collapse of cavitation bubbles to induce a therapeutic effect sonochemically. Rose Bengal (RB) has the potential to be such a sonosensitizer. Highly efficient as well as controlled generation of cavitation bubbles is crucial for realizing effective as well as safe sonodynamic treatment. The effect of RB on cavitation generation was investigated to achieve such controlled generation. The amount and behavior of the cavitation bubbles generated by a triggered HIFU sequence in the presence of RB were observed using a high-speed camera for estimating the effect of RB. Results showed that RB increased the area of the cavitation cloud and the lifetime of sustained cavitation bubbles.”