Before-and-after evaluation of an IDEA-based standardized ultrasound image documentation protocol for deep endometriosis ultrasound assessment

To evaluate the association between implementation of a standardized endocavitary sonography image-documentation protocol, developed in accordance with the International Deep Endometriosis Analysis (IDEA) consensus, and the diagnostic performance for compartment-specific deep endometriosis (DE) lesions, and to explore its feasibility as a component of routine ultrasound quality assurance. This single-center retrospective before-and-after controlled study included 783 patients who underwent dedicated ultrasound examination for DE at Peking University Shenzhen Hospital between January 2023 and September 2025 and subsequently underwent laparoscopic surgery within 6 months with complete surgical and pathological confirmation. According to the implementation of the standardized image documentation protocol in November 2024, patients were divided into a pre-implementation group and a post-implementation group. The protocol was developed based on the four-steps scanning framework of the IDEA consensus and required mandatory documentation of 19 standard sections and standardized recording of procedural information. The documentation rate of standard sections, examination duration, and diagnostic performance indices were compared between groups. A total of 783 patients were included (pre-implementation, n =267; post-implementation, n =516), with comparable baseline characteristics. Following protocol introduction, documentation rates significantly improved for 15 of 19 core ultrasound sections after Bonferroni correction ( P <0.0026), with absolute gains of 47.9%–63.3% for previously underreported sections including the uterovesical pouch, ureters, rectovaginal septum, and lower rectum. Median examination duration remained unchanged (719 vs. 723 seconds; P =0.529).For deep endometriosis at posterior compartment sites, specificity increased significantly for pouch of Douglas obliteration (80.0% to 93.9%, P <0.001) and rectosigmoid colon involvement (79.9% to 90.0%, P <0.001), with both differences remaining robust after multiple comparison correction. Sensitivity for the uterine sliding sign improved from 74.0% to 95.1% ( P <0.001). Although adenomyosis detection sensitivity also rose (82.5% to 94.9%, P =0.003), adenomyosis and ovarian endometrioma are considered endometriosis-related manifestations rather than DE-specific anatomical sites.In a subgroup analysis of 14 patients with ureteral DE, the mean ureteral diameter near the bladder orifice was significantly larger on the involved side compared with the contralateral uninvolved side (median 3.13 mm, IQR 2.70–3.30 vs. 2.15 mm, IQR 1.90–2.50; P <0.001). A standardized ultrasound image documentation protocol for dedicated DE examination, established based on the IDEA consensus, may represents a feasible quality-control strategy for DE ultrasound, without significantly prolonging examination duration. However, its clinical generalizability and effect on diagnostic consistency require further validation in large-scale multicenter prospective studies.