Objective   To identify the safety and efficacy of high intensity focused ultrasound (HIFU) ablation in treatment of adenomyosis.     Methods   Ultrasound ablation (Frequency 0.8 MHz

focal region 1.5 mm×1.5 mm×10 mm

circulating degassed water as acoustic couplant 3×10

-6

g/L) was performed in 78 adenomyosis patients suffering from dysmenorrhea with or without increase of menstrual quantity in our department from March 2007 to October 2008. All patients were surveyed regarding their pain levels ranging from 0 to 10 after the treatment immediately evaluated

by numeric rating scale (NRS). Enhanced magnetic resonance imaging (MRI) was performed in 0 to 3 months after the treatment according to imaging parameters pre-treatment to assess coagulative necrosis. Clinical evaluation using a standardized questionnaire was carried out at regular intervals after ultrasound ablation to assess patient outcome. Each complication was categorized and graded as to severity and outcome using the complication classification developed by the Society of Cardiovascular and Interventional Radiology (SIR).    Results    In all 78 patients

84.6% patients tolerated the treatment procedure well with 0 to 4 pain scores. Only one ablation was terminated because the patient had elevated blood pressure steadily. The number of the cases completely follow-up was 69

and the mean follow-up time was (11.9±6.4) months. The scores of menorrhea and dysmenorrhea after the treatment were lower than those pretreatment significantly (P005). Clinical effectiveness was observed in 62 (89.9%) of the 69 women with variety relief of dysmenorrheal. Complications were observed in 22 (87.0％) of the 69 women

more than 2 events occurred in 4 women. Twenty-three (85.1%)of 27 events are SIR A. Four (14.8%） women who experienced SIR B events recovered after symptomatic therapy. There was no serious complication

including death and major permanent injuries. And there was no prolonged hospitalization and readmission. Coagulative necrosis was observed in 60 (87.0%) of the 69 women with non-perfusion region by enhanced MRI. There was no correlation of non-perfusion region and lesion location with complication (P0.05).     Conclusion   HIFU ablation has safety and efficacy for adenomyosis treatment. Ultrasound ablation may be an option of new non-invasive treatment for symptomatic adenomyosis.