International Journal of Obstetrics and Gynecology

International Journal of Obstetrics and Gynecology | Vol. 14, No. 8, August 2026 | pp. 423–434

DOI: 10.46882/2026/IJOG/000516

Original Research Article

Title: Diagnostic Accuracy of Magnetic Resonance Imaging versus Transvaginal Ultrasound in Mapping Deep Infiltrating Endometriosis

Names of Authors: Anita P. Nwosu¹, Samuel T. Kudoyin²

Authors’ Affiliations:
¹ Reproductive Endocrinology and Infertility Unit, Department of Obstetrics and Gynecology, Lagos State University Teaching Hospital, Ikeja, Nigeria
² Department of Radiology, College of Medicine, University of Lagos, Lagos, Nigeria

Abstract:
Deep Infiltrating Endometriosis (DIE) is characterized by lesions penetrating greater than 5 mm beneath the peritoneal surface, necessitating accurate preoperative mapping. This prospective diagnostic study compared the accuracy of Magnetic Resonance Imaging (MRI) against transvaginal ultrasound (TVUS) optimized with a bowel preparation protocol for mapping specific DIE locations. One hundred and twenty symptomatic women scheduled for laparoscopic excision of pelvic endometriosis underwent both TVUS and 1.5-T pelvic MRI preoperatively. Findings from both modalities were verified against surgical visualization and histopathological confirmation, which served as the gold standard. DIE was confirmed pathologically in 84 patients (70.0%). For rectosigmoid colon lesions, TVUS and MRI demonstrated comparable sensitivities (85.2% vs. 88.9%, p = 0.54) and specificities (94.1% vs. 95.6%, p = 0.62). However, for detecting uterosacral ligament lesions, MRI achieved a significantly higher sensitivity than TVUS (89.3% vs. 71.4%, p = 0.008), though specificities remained statistically equivalent (88.9% vs. 90.5%, p = 0.74). For bladder lesions, MRI also trended toward higher diagnostic precision (sensitivity 87.5% vs. 62.5%, p = 0.046). The overall accuracy for mapping overall posterior compartment lesions was 90.8% for MRI and 81.7% for TVUS (p = 0.012). While TVUS optimized with bowel preparation remains an excellent, highly cost-effective first-line diagnostic modality for intestinal mapping, pelvic MRI provides superior diagnostic accuracy for tracking deep infiltrating endometriosis within the uterosacral and anterior retroperitoneal spaces.

Keywords: Deep Infiltrating Endometriosis; Magnetic Resonance Imaging; Transvaginal Ultrasound; Diagnostic Sensitivity; Preoperative Mapping; Pelvic Laparoscopy.

Manuscript Timeline: Received: May 15, 2026; Revised: July 03, 2026; Accepted: July 22, 2026; Published: August 06, 2026.

Citation: Nwosu AP, Kudoyin ST. Diagnostic Accuracy of Magnetic Resonance Imaging versus Transvaginal Ultrasound in Mapping Deep Infiltrating Endometriosis. International Journal of Obstetrics and Gynecology. 2026; 14(8): 423–434.

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