OP14.07: Analysis of ultrasound models to diagnose adnexal masses

To assess the clinical application of different models to diagnose adnexal masses, Simple Rules (SR), logistic regression model 2 (LR2), and ovarian-adnexal reporting and data system (O-RADS). We retrospectively recruited 151 patients with adnexal masses detected by transvaginal or transrectal ultrasound, who were performed with surgery subsequently. The clinical information, ultrasound images, and pathological results were collected. Three ultrasound diagnostic models, SR, LR2, and O-RADS, were applied to evaluate the ultrasound features of the cases and discriminate between benign and malignant tumours. Regarding the pathological results as the reference standards, the diagnostic efficacy was analysed. The misdiagnosed cases were analysed to supplement clinical experience for the diagnostic ultrasound models. The AUC values of LR2 and O-RADS were 0.940 (0.890-0.972) and 0.926 (0.872-0.963), respectively. There was no significant difference between them. The specificity of O-RADS was significantly lower than that of LR2 (P = 0.021). There were three adnexal masses that showed acoustic shadows among masses misdiagnosed by O-RADS, all of which were diagnosed correctly by SR. All of the 26 masses that presented with acoustic shadows were pathologically confirmed to be benign. There were 12 adnexal masses misdiagnosed by all the three models, three of which were correctly diagnosed via contrast-enhanced ultrasound. Another six patients (4 patients with inflammation and 2 patients with rupture of endometriosis masses) showed typical clinical symptoms and laboratory examination results. Using acoustic shadows of adnexal masses as one of the principles of O-RADS to recognise benign masses may improve the accuracy. Using contrast-enhanced ultrasound and taking medical history, clinical symptoms, and laboratory examination into consideration can help to diagnose adnexal masses.