Diagnostic accuracy of ultrasound for pediatric adnexal torsion: a systematic review and meta-analysis

Pediatric ovarian/adnexal torsion is a rare but critical gynecological emergency in which delayed diagnosis may result in irreversible ovarian ischemia and loss of function. Ultrasound is the preferred first-line imaging modality in children; however, reported diagnostic accuracy varies widely, particularly between grayscale and Doppler-based techniques. This systematic review and diagnostic meta-analysis aimed to evaluate the diagnostic performance of ultrasound modalities for detecting ovarian/adnexal torsion in girls aged 0–18 years presenting to emergency and acute care settings, and to identify factors influencing accuracy. A comprehensive search of PubMed/MEDLINE, Embase, Scopus, and Web of Science was conducted from inception through December 2025. Data were synthesized using a bivariate random-effects model to generate pooled sensitivity, specificity, diagnostic odds ratios (DOR), positive and negative likelihood ratios (PLR, NLR), and hierarchical summary receiver operating characteristic (HSROC) curves. Heterogeneity was assessed using I² statistics derived from univariate models and visualized through forest plots and bivariate boxplots. Risk of bias was assessed using QUADAS-2, and certainty of evidence was evaluated with GRADE. Thirteen studies encompassing 10,457 pediatric patients were included. For color Doppler ultrasound (10 studies, pooled N = 10,112), pooled sensitivity was 78.6% (95% CI: 70.2–85.2) and specificity was 92.4% (95% CI: 86.1–96.0), with a PLR of 10.3 (95% CI: 6.1–17.4), NLR of 0.23 (95% CI: 0.16–0.33), and diagnostic odds ratio of 43.7 (95% CI: 18.9-101.1). The HSROC area under the curve was 0.924 (95% CI: 0.897–0.951), indicating excellent overall discrimination. Grayscale ultrasound alone (5 studies, pooled N = 345) demonstrated lower accuracy with sensitivity of 65.3% (95% CI: 52.1–76.5) and specificity of 88.7% (95% CI: 79.4–94.1). Subgroup analyses showed higher specificity in emergency department-based studies (94.1% vs. 88.9%, p = 0.03), lower sensitivity among adolescents compared with younger children (71.4% vs. 82.1%, p = 0.04), and improved specificity when prespecified diagnostic thresholds were used (93.8% vs. 85.2%, p = 0.02). Certainty of evidence was rated moderate for sensitivity and high for specificity. Ultrasound, particularly color Doppler ultrasound, demonstrates high specificity and excellent overall diagnostic performance for pediatric ovarian/adnexal torsion, supporting its role as a first-line imaging modality in emergency settings. However, moderate sensitivity indicates that preserved Doppler flow does not reliably exclude torsion; clinical judgment remains essential in guiding timely surgical management. A negative study should not delay surgical consultation when clinical suspicion is high.