Diagnostic accuracy of transvaginal ultrasound using the IDEA protocol and UBESS staging compared with laparoscopy in deep endometriosis

Deep endometriosis (DE) poses diagnostic and surgical challenges. We evaluated transvaginal sonography (TVS) performed according to the International Deep Endometriosis Analysis (IDEA) protocol, and the Ultrasound-Based Endometriosis Staging System (UBESS), against laparoscopic findings and surgical complexity. This prospective pilot study enrolled 33 women with suspected DE scheduled for operative laparoscopy at a tertiary referral centre in India. A single experienced radiologist performed IDEA-based TVS and assigned a UBESS stage preoperatively; laparoscopy was the reference standard. Diagnostic accuracy was calculated from 2 × 2 contingency tables with exact 95% confidence intervals (CIs); for UBESS, Stage III (high surgical complexity) was the positive outcome. At laparoscopy, 16 women (48.5%) had UBESS Stage III and 17 (51.5%) Stage II disease; none had Stage I. TVS-derived UBESS correctly classified 13/16 Stage III and 17/17 Stage II cases (sensitivity 81.3%, 95% CI 54.4–96.0%; specificity 100%, 80.5–100%; accuracy 90.9%, 75.7–98.1%); three Stage III cases were under-staged. All laparoscopically confirmed endometriomas were correctly identified by TVS (right 30/30, 95% CI 88.4–100%; left 29/29, 88.1–100%), although specificity rested on only 3–4 endometrioma-negative patients. Sensitivity was 85.7% (18/21; 63.7–97.0%) for pouch of Douglas (POD) obliteration and 81.3–84.2% for ovarian immobility, with no false-positive findings. In this small single-centre cohort, IDEA-based TVS identified endometriomas and POD obliteration with few errors, and UBESS under-staged 3 of 16 high-complexity cases without over-staging any case. Wide CIs, absence of Stage I disease and an expert single-operator setting preclude definitive conclusions; validation in larger multicentre cohorts is required. Similar content being viewed by others

The authors thank the nursing and operating theatre staff for their commitment to protocol compliance throughout the study period. No external funding was received for this work. Funding This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Author information Authors and Affiliations Corresponding author Ethics declarations Competing interests The authors declare no competing interests. Additional information Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Rights and permissions Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/. About this article Cite this article Dudekula, A., Manium, P. & Eddula, V.R. Diagnostic accuracy of transvaginal ultrasound using the IDEA protocol and UBESS staging compared with laparoscopy in deep endometriosis. Sci Rep (2026). https://doi.org/10.1038/s41598-026-78987-0 Received: Accepted: Published: DOI: https://doi.org/10.1038/s41598-026-78987-0