EmpowHer Is magnetic resonance (MR) guided focused ultrasound a common procedure? Dr. Suzzane D. LeBlang, M.D. Nueroradiologist Right now in United States there are probably ten to 15 centers that performing the MR guided focused ultrasound procedure for uterine fibroids. Today since FDA approval in October of 2004 over 4,000 cases have been done worldwide.