Diagnostic value of subcostal liver margin diameter measured by ultrasonography for identifying paediatric hepatomegaly

Introduction: Liver size varies with age, sex and body size. Ultrasonography is a widely used modality to evaluate liver size. While craniocaudal diameter diagnoses hepatomegaly, measuring liver diameter below the costal margin in the midclavicular line may offer a simpler alternative. This study evaluated the diagnostic value of subcostal liver margin diameter for identifying hepatomegaly. Methods: In this cross-sectional study, 42 patients with hepatomegaly and 42 healthy individuals under 18 years underwent liver measurements by ultrasonography at two radiology centres. Liver diameter below the costal margin through the midclavicular was obtained, and the statistical analysis using the receiver operating characteristic (ROC) curve analysis was made. Results: Mean subcostal diameter in patients with hepatomegaly was 44.05 ± 12.84 mm and was 11.65 ± 7.89 mm in controls. ROC curve analysis demonstrated a cut-off of 20.5 to 22.5 mm for the diagnosis of hepatomegaly. Considering 2 cm as the cut-off was great for diagnosing hepatomegaly in paediatric patients without considering age. Conclusion: The study demonstrated liver diameter below the costal margin as an alternative method for identifying hepatomegaly in paediatric patients. This simpler, potentially faster measurement approach may serve as a reliable diagnostic tool.