EmpowHer When can a woman engange in sexual activities after a magnetic resonance (MR) guided focused ultrasound? Dr. Suzzane D. LeBlang, M.D. For most women after the MR guided focused ultrasound procedure, they can resume normal sexual activities the next day. In very few patients that have completely intracavitary fibroids, we ask patients to abstain from sexual activity for four to six weeks.