Many pre and post-menopausal women develop abnormal uterine bleeding. While this sometimes can be evaluated by ultrasound, MRI is frequently used for more detailed evaluation of uterine bleeding. One of the most common causes is uterine fibroids. Compared with ultrasound, MRI allows for much more anatomic detail as well as better measurements of uterine fibroids. In addition, MRI can determine which and how many fibroids are degenerating, which can be a painful condition, as well as determine the exact location of fibroids which can, in many cases, contribute to uterine bleeding. Patients who undergo uterine artery embolization for treatment of uterine fibroids contributing to excessive uterine bleeding will be imaged prior to and following uterine artery embolization with pelvic MR examinations. This allows for the evaluation of response to treatment.
Finally, adenomyosis, a condition in which the lining of the uterus grows into the muscular wall of the uterus, can contribute to significant pelvic pain and occasionally uterine bleeding. While this is an extremely difficult diagnosis to make on pelvic ultrasound due to the similar appearance of adenomyosis and fibroids, pelvic MRI is an excellent modality at differentiating fibroids from adenomyosis.
If your doctor feels a pelvic mass on manual exam, or if a pelvic mass is discovered as part of a CT scan or pelvic ultrasound, pelvic MRI is frequently utilized for further evaluation. Both benign and malignant ovarian masses can occur and are sometimes difficult to characterize on ultrasound. Due to its excellent tissue resolution and ability to differentiate between blood, fat, and other types of soft tissues, MRI is excellent at further characterizing masses within the ovary. Possibilities would include a hemorrhagic cyst (a cyst which bleeds into itself) and endometrioma (a sequelae of endometriosis), various types of benign and malignant ovarian tumors, and some conditions which may mimic an ovarian mass such as a peritoneal inclusion cyst which can occur in a patient who has had a prior hysterectomy but still has one or both ovaries remaining. An additional indication for pelvic MRI is to help differentiate a fibroid growing off the uterus which may mimic an ovarian mass on physical exam and sometimes on ultrasound. Frequently, MRI can distinguish between this type of fibroid versus a more concerning ovarian mass. Finally, hydrosalpinx, an abnormally dilated Fallopian tube, may also mimic an ovarian mass on pelvic CT scan or ultrasound. Again, MRI is frequently utilized to differentiate hydrosalpinx from a more concerning ovarian mass.
Endometriosis is a condition in which the lining of the uterus is found at different sites within the pelvis but outside of the uterus. This frequently can be a cause of significant pelvic pain and in some cases infertility and occasionally an ovarian or pelvic mass. MRI is sometimes used in the evaluation of pelvic pain as well as to evaluate for the presence and extent of endometriosis.
Ovarian, endometrial and cervical cancer may occur. As mentioned above, MRI is sometimes utilized in the evaluation of ovarian cancer. Pelvic MRI is also frequently utilized for staging of cervical cancer. In this context MRI can help determine the extent of structures involved by the cervical cancer, for example, whether or not the lower or upper uterus is involved and whether or not the structures next to the uterus such as the ureters are involved.
In some cases MRI may be used to evaluate the extent of endometrial cancer as well. MRI is sometimes utilized to evaluate for the presence and extent of rectal cancer, bladder cancer, and prostate cancer. In the case of prostate cancer, a specialized coil is inserted into the rectum to specifically evaluate the rectum or prostate. The coil is small in size and remains in place for approximately 30 minutes while the pictures are obtained. Your MRI technologist will describe the procedure in more detail on the day of your examination; however, this portion of the procedure is well tolerated by patients. As described above, MRI may be utilized for further evaluation of ovarian cancer.
The uterus is a tube-like structure which actually forms by the fusion of two smaller tubes, one on the left side of the body and one on the right side of the body to form a larger tube-like structure called the uterus. This fusion takes place in the fetus while the fetus is inside the maternal uterus. On occasion there can be a failure or a variation in the fusion between the left and right tubes during fetal development. Some of these malformations can interfere with the ability to become pregnant. MRI is excellent at evaluating the various uterine anomalies as well as any associated anomalies such as malformations in the ovaries and kidneys.