Enhanced photo-sono therapy with dual-frequency ultrasound

Photo-sono therapy (PST) is a cavitation-based anti-vascular and thrombolysis treatment strategy. Compared to conventional high intensity focused ultrasound treatment, PST can selectively treat blood vessels and clots because of optical absorption. Current methods typically combine a single-frequency ultrasound burst with pulse laser irradiation. However, the high acoustic energy required and limited treatment efficacy present a barrier to the clinical application of this technique. In this paper, we introduce a dual-frequency ultrasound approach to enhance PST efficacy with reduced acoustic energy. Through both theoretical bubble dynamics modeling and experimental study, the effect of dual-frequency ultrasound in PST is evaluated. The feasibility of the proposed method was validated using ex vivo blood vessel and blood clot phantoms, as well as an in vivo rabbit model. Results show that dual-frequency PST enhances cavitation activity, thrombolysis, and anti-vascular efficiency, highlighting its potential for clinical translation.