In this issue of JVIR, Gorny et al (1) report their experience with the use of magnetic resonance (MR)– guided focused ultrasound (US) therapy for uterine fibroids with the ExAblate 2000 (InSightec Inc, Haifa, Israel), a device that has received U.S. Food and Drug Administration approval. After a mean follow-up of 2.8 years of 138 patients who received MR-guided focused US, 19% and 23% of the patients had undergone a second procedure for recurrence of fibroid-related symptoms at 3 and 4 years, respectively, based on KaplanMeier estimates. Predictors of successful MR-guided focused US therapy included older patient age and MR imaging characteristics of the fibroids (homogeneously dark fibroids on T2-weighted images). The study was limited by lack of symptom and quality-of-life assessments, a skewed patient population (90% white), absence of imaging follow-up, and the need to treat approximately 48% of patients (66 of 138) twice with MR-guided focused US (1). The mean nonperfused volume (NPV) of fibroids reported by Gorny et al (1) was only 45.5%, whereas other investigators have found a statistical correlation between larger NPV ratios and a reduced need for additional treatments (2) and greater reductions in fibroid volumes after MR-guided focused US (3). Trumm et al (4), using the newer ExAblate 2100 system (InSightec), which has not received Food and Drug Administration approval, were able to achieve a mean NPV of 88% in 115 women. In addition, this same group from Germany reported on a cohort of 190 patients who received MRguided focused US, of whom 82% achieved 4 80% NPV (5). A subanalysis of patients who had Z 85% NPV showed greater improvements in symptom severity