Magnetic resonance-guided focused ultrasound surgery (MR-guided FUS) is a noninvasive method for treating uterine fibroids. Also called focused ultrasound surgery, or focused ultrasound ablation, the procedure directly targets these benign tumors in the uterus with high-intensity ultrasound waves that heat and destroy them.
An interventional radiologist performs the procedure in a magnetic resonance imaging (MRI) scanner. MRI scans help pinpoint the position, thickness and appearance of the fibroids as well as identify adjacent tissues in the body that should not be involved in the surgery.
To prepare for the procedure, patients are instructed to shave their lower abdomen between the pubic bone and belly button. Once at the treatment location, they receive a gown to wear.
After being lightly sedated, the patient lies facedown on an examination table in the MRI scanning room with their arms extended forward. The pelvis rests on a gel pad for direct skin contact, and a coil is placed over the area to help the radiologist secure MR images that show precisely where the uterine fibroids are located and any nearby organs that should not be targeted.
After the table is moved into the core of the MRI scanner, high-frequency sound waves, or sonications, inaudible to humans, are focused on small areas of the fibroids. These ultrasound waves produce heat that is high enough in temperature to destroy the fibroids without damaging the surrounding healthy tissue.
Focused ultrasound surgery is an effective treatment for many common and unpleasant symptoms of uterine fibroids, such as excessive menstrual bleeding, extended menstrual periods, pelvic pain and pressure and frequent urination.
The outpatient procedure, which takes several hours to complete, offers individuals many advantages over surgery. First and foremost, the uterus remains intact, and the patient’s fertility is preserved. Second, because no injections or incisions are needed, recovery time usually requires only resting for a few hours after the procedure to allow the sedative to wear off. Patients can return home the same day and should be able to resume their normal activities within a day or two after treatment. Finally, the procedure does not expose the patient to any radiation.
According to the Radiology Society of North America, the ideal candidates for MR-guided FUS therapy are those with fewer than four fibroids or tumors of less than 500 milliliters in volume.
Among those who should not undergo MR-guided FUS are patients with pedunculated fibroids (those attached to the uterine wall by a stalk), scarring of the lower abdominal wall that might block the path of the ultrasound waves, potential cancerous tissues near the uterus, pelvic infection, pregnancy, calcified fibroids and fibroids too close to nerve roots near the lower spine near the backside.
Some women may feel post-surgery abdominal or pelvic pain, redness or burns on the skin, bleeding or bruising. But these effects usually resolve within a week or two.
Most individuals experience a rapid resolution of their fibroid symptoms after focused ultrasound surgery.