Pelvic MRI and Other Tests to Diagnose Uterine Fibroids

The majority of women discover they have uterine fibroids during a routine OB/GYN examination. Traditionally, the OB/GYN will follow up with an imaging test to confirm the presence of fibroids.

Pelvic Ultrasound

The most popular imaging test and most often performed to confirm the presence of fibroids is a pelvic ultrasound. Most OB/GYN offices already own an ultrasound machine so the test is easily accessible. Historically, the cost has been less than obtaining an MRI, although the gap is decreasing.

Ultrasound imaging uses sound waves that are transmitted from a probe used either transabdominally (placed on the skin) or transvaginally (inserted in the vagina). The waves are translated into images that can be viewed on a black and white screen but the resolution of the images can be grainy and unclear. While ultrasound can detect fibroids, and therefore confirm the diagnosis, many machines lack the ability to provide little else. The body habitus of many patients and the presence of bowel gas also limit ultrasound evaluation. The highest resolution and most accurate imaging test to diagnose fibroids is MRI.

MRI – Magnetic Resonance Imaging

Magnetic resonance imaging uses a magnetic field and radio waves that are turned into highly detailed images of the organs and tissues in your body. MRI is considered the gold standard in diagnosing fibroids because the resolution provided is much higher than the resolution of ultrasound imaging. Details that are not apparent on the ultrasound exam can be viewed clearly with MRI.

pelvic ultrasound vs pelvic MRI
Pelvic Ultrasound vs. Pelvic MRI

In fact, a number of patients that presented with clinical findings of fibroids and an enlarged uterus had been misdiagnosed as having fibroids when an MRI revealed adenomyosis – a completely different gynecological condition.

An MRI of the pelvic area can provide details in terms of how many fibroids are present as well as their size. It can also show other issues that may be causing symptoms to assist in a proper treatment plan. Today, an MRI is more affordable than years ago, and the resolution produces far superior images making it the preferred method in the evaluation of the symptomatic fibroid patient.

What to Expect During an MRI

Sometimes the patient will be provided with a gown to wear. Other times the patient’s clothing is permitted as long as there is no metal present. If you have earrings, rings, or anything made of metal, it must be removed. If you have any metal in your body such as plates, pins, pacemaker, etc., you need to inform the technician.

An MRI is not painful but some find the tunnel-like machine loud and confining. Unlike an ultrasound that uses sound waves and a wand-like device, the patient lies down on a bed that moves in and out of a tube-like structure. There is a large donut-shaped magnet that the bed passes through. Using the water molecules in your body and radio waves, it creates detailed pictures of your organs.

The patient is asked to lie as still as possible as the images are being captured. The imaging technician will normally provide you with some earplugs because, throughout the scan, you will hear loud buzzing and tapping noises that turn on and off. An MRI can for fibroids typically takes around 30 minutes.

MRI Scanner
MRI Scanner

Other Imaging Tests

Hysterosonography is another imaging test used to diagnose uterine fibroids. It is also called a saline infusion sonogram and is done by inserting a thin tube into the uterus, through the vagina. Ultrasound pictures are taken while a sterile saline solution is introduced through the catheter to open up the uterine cavity. This procedure is helpful to identify submucosal fibroids and observe the uterus lining.

Hysterosalpingography is an X-ray test that uses dye to assist the doctor in the examination of the uterine cavity and fallopian tubes highlighting any blockages and can also reveal submucosal fibroids.

Hysteroscopy – an instrument called a hysteroscope, which resembles a small telescope with a light, is inserted through the cervix into the uterus, and similarly to hysterosonography, saline is used to expand the uterus, thereby allowing the doctor to examine the uterine walls and openings of the fallopian tubes.