Diagnostic Accuracy of American College of Radiology Ovarian-Adnexal Reporting and Data System (ACR O-RADS) Ultrasound for Characterizing Adnexal-Ovarian Masses: A Histopathological Correlation Study

BackgroundAccurate preoperative characterization of adnexal-ovarian masses is essential for appropriate clinical management.The American College of Radiology Ovarian-Adnexal Reporting and Data System (ACR O-RADS) ultrasound provides a standardized ultrasound-based framework for malignancy risk stratification. ObjectiveThe objective of this study is to evaluate the diagnostic accuracy of transvaginal ultrasonography (TVUS) using ACR O-RADS for adnexal-ovarian masses, with histopathological diagnosis as the reference standard. Materials and methodsThis prospective, single-center, hospital-based observational diagnostic-accuracy study with a crosssectional index-test/reference-standard comparison was conducted over 18 months, from May 2023 to November 2024.Women with suspected adnexal-ovarian masses underwent TVUS, and each lesion was categorized according to the ACR O-RADS ultrasound system.Histopathological examination following surgical excision served as the reference standard.Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated and reported with Wilson 95% CIs. ResultsAmong the 34 adnexal-ovarian masses, histopathological examination classified 16/34 (47.1%; 95% CI: 31.5%-63.3%)as malignant, 15/34 (44.1%; 95% CI: 28.9%-60.5%)as benign, and 3/34 (8.8%; 95% CI: 3.0%-23.0%)as borderline.When O-RADS categories 4 and 5 were considered test-positive and malignant/borderline lesions were combined as disease-positive, O-RADS demonstrated a sensitivity of 100.0%(95% CI: 83.2%-100.0%),specificity of 66.7% (95% CI: 41.7%-84.8%),PPV of 79.2% (95% CI: 59.5%-90.8%),and NPV of 100.0%(95% CI: 72.2%-100.0%).O-RADS category was significantly associated with histopathological classification (p < 0.001); however, the proportion of malignant lesions was identical in O-RADS 4 and O-RADS 5 (66.7% each). ConclusionACR O-RADS demonstrated promising diagnostic performance for characterizing adnexal-ovarian masses in this cohort.These findings require confirmation in larger, consecutively recruited populations before broader conclusions regarding clinical utility can be made.