MRgFUS FAQs

Pressure in the bladder

What are fibroids?

Fibroids are round muscle growths that develop within the uterus (womb). Fibroids are almost always benign (non-cancerous). Fibroids range in size from as small as a pea to as large as a melon. They are also called leiomyomas or myomas.

Could my fibroids come back after this treatment?

Although this treatment may be successful in destroying the fibroids that are causing painful symptoms, it is possible that at a later time more fibroids could grow, become symptomatic and require additional treatment. This is true for all fibroid treatments, except hysterectomy where the entire uterus is removed.

Where can I learn more about fibroids?

You can learn more about fibroids at the UCSF Comprehensive Fibroid Center.

What is Focused Ultrasound?

Focused ultrasound (FUS) uses tightly focused high-energy ultrasound waves to kill tissue. Sound waves passing through tissue are partially absorbed and converted to heat. With proper focusing and sustained energy input, a small and targeted focus of heating (temperatures of 65-850C/149-1850F are produced in the focal zone) can be achieved at varying depth within tissues and adjusted to kill a small (size of a grain of rice) piece of a tumor. Larger volumes of tumor can be treated piece by piece. The use of focused ultrasound waves to heat and destroy a piece of tumor is like using a magnifying glass to focus the sun’s energy on a single spot and heat it.

  • History - The principle of using high-energy ultrasound beams for disease treatment dates to 1954, but early efforts were limited by lack of image guidance and lack of accurate monitoring of treatment effects. In 1984, extracorporeal shockwave lithotripsy (fragmentation of urinary stones by targeted high energy ultrasound) became the first clinical application of high energy ultrasound for disease treatment to be approved by the FDA. Interest in FUS for tumor ablation re-emerged in the 1990s due to the convergence of advances in medical imaging, ultrasound technology, and focal therapy.
    The FDA approved focused ultrasound for the treatment of fibroids in 2004.  In July 2010, UCSF became the first site in the country to be awarded a high-end instrumentation grant from the National Institute of Health for purchase of an MRgFUS system. The installation of the NIH-funded Insightec MRgFUS system in early 2011 thus allowed UCSF to begin offering this cutting edge therapeutic technology to patients in Northern California and across the country.
  • UCSF, a pioneer - Focused ultrasound is no longer just for research; it is now being used clinically.  However, while this has been FDA-approved since 2004, it is still considered investigational therapy.  As a result, it is not covered by all insurances.

How is MRgFUS different from standard ultrasound?

Standard ultrasound (i.e. diagnostic ultrasound for imaging) uses transient low energy ultrasound waves to create images of structures within the body. The energy is not focused on a single spot and does not create high temperatures.

Is FUS the same as high intensity focused ultrasound (HIFU)?

Yes, Focused Ultrasound and High Intensity Focused Ultrasound are the same.

Why is MRI used to guide and monitor FUS?

MRI provides distinct advantages for guiding focused ultrasound. An MRI thermal imaging system is used to continuously measure temperature changes inside the body, pinpointing and guiding the treatment.

Is a presurgical MRI required for MRgFUS?

A pelvic magnetic resonance imaging (MRI) scan is typically performed before treatment to determine whether the patient is a good candidate for MRgFUS.

The MRI tells the interventional radiologist:

  • How susceptible the fibroid will be to treatment.
  • The position of anatomical structures.  If another structure is in front of the fibroid, for example, then the ultrasound energy would destroy the structure before the fibroid.
  • How well the fibroid takes the contrast agent.  Research has shown that if the fibroid takes the contrast agent very well, then the patient will be a good candidate for MRgFUS.
  • The location of the fibroid. Because the ultrasound energy can only penetrate 12 centimeters, if a patient has a fibroid farther than 12 centimeters from the belly surface, then she will be advised that the chances of success for destroying the fibroid using MRgFUS are very low. 
  • The size of the fibroid.  By measuring the fibroid, it is possible to determine its volume.  In cases where the fibroid exceeds 500 cc’s, MRgFUS will not be recommended.

After the patient has received an MRI, the interventional radiologist reviews the MRI to determine if the patient is a viable candidate for MRgFUS.

Do I need to stay in the hospital after MRgFUS?

No. This is an outpatient procedure. You will need to stay for one to two hours after the procedure and then you will need someone to accompany you on the way home. Women return to their normal activities within a few days after the procedure.

Can my fibroids be treated by MRgFUS?

Women who are having symptoms related to fibroids such as heavy bleeding, pelvic pressure, or urinary frequency may be eligible for MRgFUS. At your initial visit, you and the gynecologist, in collaboration with the interventional radiologist, will discuss whether your fibroids can be treated by MRg-FUS. We will discuss your symptoms and your treatment goals, and review the position and size of your fibroids with radiology imaging (pelvic ultrasound and/or MRI). We will also review with you other possible treatment options for your fibroid-related symptoms including nonsurgical and surgical possibilities.

What are the risks of MRgFUS?

On rare occasions, MRgFUS can cause:

  • Burns to the skin on the patient’s abdomen.
  • Damage to tissues and structures near the fibroid targeted for treatment.
  • Severe discomfort or nerve pain during the procedure.

MRgFUS is not for every patient.  Consider that with this procedure:

  • Some fibroids may not be able to be treated.
  • Further treatment may be required if symptoms return.
  • There is no long-term data on safety and effectiveness.
  • Its availability is currently limited to specialized treatment centers.
  • It is not an option for women who want to optimize the chance of a future pregnancy.
  • Some complications and side effects may still be unknown because the procedure is so new.

Do I need to have my MRI at UCSF?

No you don’t.  However, if you have the MRI at a facility other than UCSF, you risk having the MRI performed below the required standards for focused ultrasound surgery.  For example, if the MRI facility neglects to inject contrast agent prior to the MRI you would then have to undergo a second MRI.  Having the MRI at UCSF ensures that the MRI will be done as required in these cases, according to our protocol for MRgFUS.  In addition, you will get the result of whether you are a candidate more quickly because outside MRIs have to be sent to UCSF and uploaded onto UCSF’s server.

How can I make an appointment for MRgFUS?

If you are interested in undergoing MRgFUS for your fibroids, please see information about referrals and scheduling.

What is an Interventional Radiologist (IR)?

An interventional radiologist (or an IR doctor) is a physician who performs minimally invasive procedures using different imaging modalities (MRI, CT, ultrasound (US), X-ray).  An IR is a highly trained radiologists who can treat a wide variety of disease conditions such as uterine fibroids.

How can I learn more?

You can learn more about the medical specialty of interventional radiology and the training of interventional radiologists at the Society of Interventional Radiology website.

You can learn more about fibroid treatment at the UCSF Comprehensive Fibroid Center.