Transabdominal ultrasound for positive, negative, and equivocal ovarian and tubal torsion in girls

BACKGROUND: Adnexal torsion diagnosis in children relies heavily on ultrasound, but existing literature lacks standardization of technique and handling of equivocal results. PURPOSE: To assess the accuracy of transabdominal ultrasound (US) in diagnosing adnexal torsion in pediatric patients and evaluate optimal clinical decision-making for equivocal US reads. MATERIALS AND METHODS: Retrospective review of pelvic US exams and surgical data for girls aged 1-18 years from 2015 to 2019 at a pediatric quaternary care hospital. US reports were coded as positive, negative, or equivocal for torsion. Surgical findings were used to confirm final diagnosis. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated under various scenarios for handling equivocal reads. RESULTS: This study included 4,396 ultrasound exams from 3,707 patients (median age, 15.2 years IQR: 12.8-16.8). Ovarian visualization rate was 97-98%. US was read as positive for torsion in 1% of adnexae, negative in 95%, and equivocal in 4%. Among 179 surgical cases, torsion was present in 52%. Sensitivity of US for torsion was highest (86.0%) when equivocal cases were considered positive (EqP), but PPV was lowest (29.9%) under this condition. Area under the ROC curve was greatest (0.8651) when equivocal US were counted as positive. US reads were more likely to be true positive for isolated ovarian torsion compared to when tubal torsion was present (p = 0.003). CONCLUSION: A standardized transabdominal US protocol yields high ovarian visualization rates, and treating equivocal reads as positive can optimize diagnostic accuracy when combined with clinical decision-making. US maybe be less accurate in detecting tubal torsion compared to isolated ovarian torsion, but this finding should be interpreted with caution given the small sample size. Overall, these results provide clinically relevant insights to guide management and future research in pediatric adnexal torsion.