Evaluation of Signal Characteristics of Extrapelvic Deep Infiltrating Endometriosis on Mri and Comparison With Myometrium; [بررسی خصوصیات اندومتریوزیس عمقی خارج تخمدانی در سکانس‌های ام آر آی و مقایسه آنها با میومتر]



Moradi B ; Rahmani M ; Maqsoodlou S ; Fazelnia F ; Malek M ; Davari Tanha F ; Kazemi M A
Source: Tehran University Medical Journal Published:2025

Abstract

Background: Deep infiltrating endometriosis (DIE) is the most severe form of endometriosis and is characterized by infiltration of endometrial tissue deeper than 5 mm beneath the peritoneal surface. Accurate preoperative mapping of lesions is essential because DIE commonly involves the rectosigmoid colon, uterosacral ligaments, retrocervical space, bladder, and abdominal wall. Magnetic resonance imaging (MRI) is considered one of the most valuable noninvasive imaging modalities for evaluating the extent of disease; however, overlap between MRI signal characteristics of DIE lesions and normal myometrium may reduce diagnostic specificity in certain anatomical regions. This study aimed to evaluate MRI signal characteristics of extrapelvic DIE lesions and compare them with those of the myometrium across different MRI sequences.Methods: In this retrospective cross-sectional study, 170 patients with confirmed extrapelvic DIE who underwent dedicated pelvic MRI between June 2017 and September 2022 at Imam Khomeini Hospital, Tehran, were evaluated. MRI examinations included T1-weighted, T2-weighted, diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) mapping, and post-contrast dynamic sequences.Signal intensity measurements were obtained using ROI-based analysis and compared with outer myometrium. Statistical analysis was performed using the Mann–Whitney U test, and p≤0.05 was considered statistically significant. Results: A total of 170 patients with deep infiltrating extrapelvic endometriosis were evaluated. Compared with myometrium, lesions involving the rectum and rectosigmoid, retrocervical space, uterosacral ligaments, anterior compartment, and abdominal wall demonstrated significant differences in multiparametric MRI characteristics, whereas posterior fornix lesions showed no significant differences.Conclusion: MRI signal characteristics of extrapelvic DIE are location-dependent and may partially overlap with those of the myometrium. Multi-parametric MRI, particularly functional and dynamic sequences, improves lesion characterization and provides valuable information for accurate preoperative assessment and lesion mapping in patients with DIE. These findings may also contribute to improved surgical planning, optimized the rapeutic decision -making, and reduction of unnecessary invasive diagnostic procedures in affected patients. Copyright © 2025 Moradi et al. Published by Tehran University of Medical Sciences. This work is licensed under a Creative Commons Attribution-Non-Commercial 4.0 International license (https://creativecommons.org/licenses/by-nc/4.0/). Non-commercial uses of the work are permitted, provided the original work is properly cited.