Purpose: To evaluate the efficacy of non-invasive magnetic resonance (MR) imaging-guided focused ultrasound (FUS) treatment of uterine fibroids.

Methods and Materials: Twenty two women (mean age 49.1year ) with symptomatic uterine fibroids , were treated by MR imaging guided FUS. All the women had a pre-treatment multiplanar MRI to identify the fibroid for the FUS treatment based upon T2-weighted imaging. The FUS treatment is based upon sequential sonications of the target volume. Temperature-sensitive phase-difference-based MR imaging is performed during each sonication to monitor focus localization and tissue temperature changes. After treatment, T1-weighted contrast-enhanced imaging was performed to evaluate the treated volume. Clinical improvement is assessed by a detailed questionnaire. Imaging follow-up is performed using T2 and T1-weighted MR imaging.

Results: The procedure was successful in all patients. In six women one fibroid was treated and in two women more than one fibroid was treated. The fibroid volume ranged from 15ml3 to 400ml3 with a mean volume of 109.3ml3 . The percent of treated volume ranged from 8.5% to 57.5% with a mean percent of 30.2%. The treated volume was measured as the area of partial lack of enhancement after treatment. All women reported improvement in their vaginal bleeding. There were no complications.

Conclusion: Our preliminary results suggest that a non-invasive MR imaging guided FUS is an effective treatment for uterine fibroids