Endometriosis in magnetic resonance imaging: essentials for radiologists and clinicians

Endometriosis is a chronic disease, characterized by the growth and implantation of endometrial tissue outside the uterus, usually in deep pelvic structures, often resulting in inflammation, fibrosis and pain.The ovaries, the uterosacral ligaments, the rectovaginal septum, and, less frequently, other parts outside of the pelvis such as the diaphragm and the sciatic nerve are frequently affected.Timely diagnosis remains a challenge despite the high prevalence due to the heterogeneous clinical presentation.Magnetic resonance imaging (MRI), provides better resolution compared to other imaging modalities and helps identify different forms of the disease, including superficial, deep infiltrative endometriosis (DIE) and endometriomas.This review describes the recommended MRI protocol, descriptions of key imaging findings, the Deep Pelvic Endometriosis Index (dPEI) and the MRI consensus lexicon, and the ENDOVALIRM group's compartment-based approach an MRI-based system that helps classify disease by severity and location for guiding clinical decisions, support preoperative planning and predict surgical outcomes.According the compartment-based approach an MRI-based system, two horizontal lines divide the pelvis into an anterior, a middle and posterior region.In addition, vertical lines divide the pelvis into a central, a left and a right compartment.This anatomical framework creates 9 compartments: anterolateral, anteroventral, mediolateral, midcentral, posterolateral, posterior-central with additional extrapelvic areas.This review aims to support radiologists and gynecology teams in the accurate detection and classification of endometriosis through standardized MRI interpretation, increasing diagnostic confidence and contributing to better surgical and clinical outcomes.