The Role of MRI in Diagnosis and Pre-Surgical Mapping of Endometriosis

Endometriosis is a chronic multisystem disease caused by the presence of endometrium-like tissue outside the endometrial canal, inciting inflammation and fibrosis. Transvaginal ultrasound (TVUS) and MRI have replaced diagnostic laparoscopy as the noninvasive imaging modalities of choice for diagnosis and pre-surgical planning. Advanced disease in the pelvis can distort/obliterate anatomic planes and obscure the extent of pelvic organ involvement at laparoscopy. Unlike laparoscopy, MRI is not limited by anatomic distortion and provides accurate multi-compartment assessment of deep pelvic endometriosis involving the uterus and its ligaments, adnexa, bowel, distal ureters, urinary bladder, and pelvic nerves. Additionally, MRI can help detect extra-pelvic organ involvement in the same study. Use of a dedicated MRI protocol and structured reporting template improves multidisciplinary communication and provides a pre-surgical road map; helps patient counseling as well as assessing the need for additional intraoperative organ-specific expertise such as colorectal surgery or urology. Knowledge of MRI and laparoscopic correlation enhances recognition of the key MRI findings to include in the report for optimizing surgical outcomes. This article focuses on the role of MRI in the diagnosis and pre-surgical mapping of pelvic endometriosis, with correlation to laparoscopic findings. Evidence level: 1. Technical efficacy: 5.