Objective：To ascertain the best time to improve the efficiency of high-intensity focused ultrasound（HIFU） ablation，accord－ing to the individual differences between patients. Methods：In a prospective study，109 patients with single uterine myoma were treated with HIFU ablation under ultrasound guidance. Patients were divided into groups according to their admission number：the single number was included in the ultrasound contrast group，and the SonoVue procedure was performed before HIFU. When the mi－crobubbles began to enter the target area under ultrasonic monitoring，HIFU ablation was immediately initiated. In contrast，patients in the control group underwent no preoperative angiography and were only treated with HIFU ablation. Data from the HIFU treatment and after surgery were analyzed and compared between the groups. Results：The ablation rate of the CEUS group and control group was more than 70%. Average sonication power，treatment time，sonication time，total energy，and energy efficiency factor were significantly lower in the CEUS group compared to the control group（P<0.05）. Dosage and irradiation time of the ultrasound treatment were signif－icantly reduced compared with that in previous studies. Additionally，no major adverse events occurred after the ablation treatment in both groups. After three months of follow-up investigation，the myomas had healed and the clinical symptoms were alleviated in some patients. Conclusion：Immediately after the contrast medium enters the target area，HIFU ablation has the strongest synergistic effect in addressing the individual differences and achieving precise and efficient ablation in different patients.
