Magnetic resonance imaging (MRI) of the uterus or pelvic area is often done to diagnosis conditions such as fibroids or endometriosis. A uterus MRI may also be performed to determine whether a mass in the ovaries, cervix, or uterus is benign or cancerous. The uterus MRI may also be performed if a woman has unexplained infertility or vaginal bleeding.
In some cases, an ultrasound of the uterus is performed before the MRI. An ultrasound isn't as clear as a uterus MRI, so it cannot positively diagnose conditions such as endometriosis. An MRI can determine whether a woman has masses in her uterus that suggest endometriosis. If the condition is suspected, a doctor may perform a laparoscopy to more closely examine the inside of the uterus and confirm endometriosis.
Another common reason for a uterus MRI is to diagnose causes of uterine bleeding or to identify fibroids, benign tumors that grow on the wall of the uterus. While in many cases fibroids are asymptomatic, some women may experience bleeding or very heavy periods as well as sharp pain in the pelvic area. Depending on their size, they can also interfere with a woman's ability to get and stay pregnant.
Although ultrasound may be the imaging of choice to diagnose fibroids and bleeding, a uterus MRI may give clearer results. Ultrasounds are usually preferred because they are less expensive than an MRI. An MRI can give an exact picture of where the fibroids are located in the uterus and whether they have begun to break down, often a cause of excessive bleeding.
An MRI of the uterus can also be used to identify other uterine masses more accurately than an ultrasound or other imaging. A condition known as adenomyosis, in which the endometrial lining grows into the muscle wall of the uterus, is difficult to distinguish from fibroids with an ultrasound alone. An MRI is also commonly used to diagnose cancer of the uterus, the most common of which is endometrial cancer. The imaging allows the doctor to see how much the cancer has spread and to determine the stage of the cancer.
A uterus MRI can also evaluate the cause of a woman's infertility. In some cases, a woman's uterus may not have formed properly, which can cause difficulties in becoming pregnant. A woman with unexplained fertility may wish to undergo an MRI so that the doctor can examine her uterus and determine if an abnormality of the organ is the cause of infertility.