Deep Infiltrating Endometriosis: Magnetic Resonance Imaging Diagnosis and Surgical Correlation

Deep infiltrating endometriosis is a severe form of endometriosis characterized by the presence of ectopic endometrial tissue that penetrates deeply into pelvic structures and is associated with significant fibrosis. Its pathophysiology involves multiple mechanisms, including retrograde menstruation, coelomic metaplasia, and lymphovascular spread, followed by a fibrotic response mediated by myofibroblasts and transforming growth factor-β. Hormonal dependence on estrogen and a chronic inflammatory microenvironment further promote lesion persistence and progression. The disease commonly affects the uterosacral ligaments, rectovaginal septum, rectosigmoid colon, and urinary tract, often presenting in a multifocal distribution that complicates both diagnosis and management. Clinically, deep infiltrating endometriosis manifests with chronic pelvic pain, dysmenorrhea, dyspareunia, dyschezia, and, in some cases, dysuria. However, symptoms are often non-specific, and physical examination is frequently insufficient for accurate diagnosis. Imaging therefore plays a central role, with transvaginal ultrasound serving as the first-line modality and magnetic resonance imaging providing a more comprehensive assessment when further evaluation is required. Magnetic resonance imaging is essential for lesion characterization and mapping, demonstrating typical findings such as hypointense fibrotic nodules on T2-weighted sequences and hyperintense hemorrhagic foci on T1-weighted images. A compartment-based approach enhances diagnostic accuracy and facilitates correlation with surgical findings. Magnetic resonance imaging also plays a key role in preoperative planning by predicting lesion extent, depth of infiltration, and involvement of critical structures such as the bowel and ureters. Despite its limitations, including reduced sensitivity for small lesions and operator dependency, magnetic resonance imaging remains a cornerstone in the management of deep infiltrating endometriosis, improving diagnostic precision, guiding surgical strategy, and optimizing patient outcomes.