MR imaging in deep pelvic endometriosis: a pictorial essay

Deep pelvic endometriosis is an important gynecologic disorder that is responsible for severe pelvic pain and is defined as subperitoneal invasion that exceeds 5 mm in depth. Deep pelvic endometriosis can affect the retrocervical region, uterosacral ligaments, rectum, rectovaginal septum, vagina, urinary tract, and other extraperitoneal pelvic sites. It is commonly associated with dysmenorrhea, dyspareunia, pelvic pain, urinary tract symptoms, and infertility. Because surgery remains the best therapeutic option for affected patients, the accurate preoperative assessment of the extension of endometriotic disease is extremely important. Pelvic magnetic resonance (MR) imaging is a noninvasive method with high spatial resolution that allows multiplanar evaluation of deep pelvic endometriosis and good tissue characterization, but without the use of ionizing radiation or iodinated contrast agents. MR imaging yields important findings that help grade the disease and identify subperitoneal lesion extension and other associated disease entities, thereby facilitating accurate diagnosis and adequate treatment. Radiologists should be familiar with the MR imaging findings of deep infiltrating endometriosis in various anatomic locations so that they can provide information that allows adequate presurgical counseling.