Pelvic MRI for Fibroids: Imaging with an MRI to Identify Uterine Fibroids
Some patients wonder why they need to undergo a pelvic MRI for fibroids when they have had a pelvic ultrasound. While ultrasound can diagnose fibroids, it significantly underestimates the number of fibroids due to a much lower resolution than MRI.
Because of the higher resolution with MRI, it will often see things that were not seen on the ultrasound exam.
Uterine fibroids are benign tumors in the uterus, which are diagnosed in 30-40% of women. This is the most common tumor of the female reproductive system. A number of women have fibroids and no symptoms. MRI imaging is typically reserved for women with symptomatic uterine fibroids.
MRI For Fibroids: The Most Reliable Diagnostic Method
The easiest and most reliable way to detect fibroids in a timely manner is to get an annual checkup with your doctor.
The presence of fibroids can be detected during a biannual physical gynecological examination. Fibroids can enlarge the uterus to a similar size pregnancy. For example, if a woman’s uterus is enlarged by fibroids and it felt up to the belly button, that is equivalent to a 16 week (4 months) size
Once the diagnosis is suspected based on the physical exam and clinical findings, often the next step is to confirm this with an imaging study.
Because most Gynecologists have an ultrasound in their office (or in close proximity) and the modality is relatively inexpensive, this is often the imaging tool used to confirm the diagnosis of uterine fibroids.
1.Ultrasound: This study uses sound waves that are sent out and reflected back to a transducer probe. This information is made into images in real-time. The exam usually consists of two parts and uses two different ultrasound probes.
This first utilizes the transabdominal probe which scans on the outside of the body. A small amount of warm gel is placed on the probe head which is used to scan the woman’s pelvic area from a “bird’s eye view.”
The second part utilizes a transvaginal probe which is gently placed inside the vagina for internal scanning. The combination scanning is necessary to ensure all of the pelvic organs can be clearly viewed as sometimes these can be obscured on one of the two scans.
2. MRI: This exam utilizes magnetic and radiofrequency waves to create high-resolution images of the pelvis.
The detail provided is much higher than ultrasound and often sees details that are not apparent on the ultrasound exam. In fact, a number of patients that present with clinical findings of fibroids and an enlarged uterus have been misdiagnosed as having fibroids when on MRI imaging it is shown to be due to adenomyosis (See Example 3).
The cost of an MRI exam has come down dramatically over the past several years and, in most cases, is comparable to the cost of an ultrasound exam [particularly if the MRI is performed at an independent (i.e. non-hospital) outpatient facility].
The following 3 examples are pelvic MRI images from 3 different patients. They are all in the sagittal plane (side or profile view).
Example 1: Normal uterus.
No fibroids present. Note the normal uterine size.
The white line is the uterine cavity. The thin dark lines on either side of the cavity are the transition between the uterine lining and the muscular uterine wall (bright gray).
Example 2: Uterine fibroids.
Note the enlarged uterus due to multiple fibroids (black circles).
Example 3: Diffuse adenomyosis.
The uterus is enlarged up to the belly button (dark line at the upper left corner of the image).
Note the thin dark lines present in Example 1 are not seen and are replaced by very thick dark areas that surround the cavity (white line). Within these thick dark areas, there are innumerable white dots which is characteristic of cystic foci of diffuse adenomyosis.
This patient with adenomyosis had been told over many years (from multiple pelvic ultrasounds) that her uterine enlargement was due to fibroids and underscores the importance of obtaining MRI imaging.
How To Prepare For An MRI For Fibroids
While some MRI examinations may require a simple prep beforehand or only scan you during a certain phase of your menstrual cycle, that is not necessary for our scanning purposes.
It is advisable to wear loosely fitting clothing and remove any metal prior to your appointment. If you have a pacemaker or any implanted metal in your body, please advise the MRI technologist.
At the imaging center, one of the staff may even scan your body with a wand similar to a TSA screen at the airport.
If you are considering UFE (Uterine Fibroid Embolization) for the treatment of your uterine fibroids, you will need to undergo a pelvic MRI exam.
This is typically performed without any interavenous (iv) or oral contrast. However, if you do undergo UFE with the Atlanta Fibroid Center and Dr. Lipman, the 3 months follow-up MRI exam is done without and with iv contrast. This is to confirm that the fibroids are infarcted (dead).