Accuracy of Lung Ultrasound Compared to Chest Radiography for Diagnosing Pneumonia in Children: A Hospital-Based Cross-Sectional Study

Abstract

Background: Traditionally, pediatric pneumonia is diagnosed through clinical examination and chest radiography (CXR), with computed tomography (CT) reserved for complications. Lung ultrasound (LUS) has gained popularity due to its portability and absence of ionizing radiation. This study evaluates LUS's accuracy compared to CXR in diagnosing pneumonia in children. Methods: We conducted a cross-sectional study from April to September 2023 involving 108 children aged 14 or younger admitted with pneumonia. Each child underwent LUS using a 5-zone scanning protocol, followed by CXR, with the latter interpreted independently by two consultant radiologists. Agreement between LUS and CXR for diagnosing consolidation and interstitial pneumonia patterns was assessed using Cohen's Kappa (k) with SPSS version 26.0. Results: Pneumonia was radiographically confirmed in 79 children (73.1%). LUS detected consolidation in 41.7% of cases, compared to 43.5% for CXR, demonstrating a sensitivity of 97.8%, specificity of 95.2%, positive predictive value (PPV) of 93.6%, and negative predictive value (NPV) of 98.4%. LUS showed higher accuracy for interstitial lung patterns (sensitivity 93.6%, specificity 97.4%). The agreement between LUS and CXR was excellent, with Cohen's Kappa values of 0.908 for consolidation and 0.863 for interstitial pneumonia. LUS also identified more pleural effusions (11.1%) compared to CXR (6.5%). Conclusion: LUS demonstrates comparable diagnostic accuracy to CXR for pneumonia, exhibiting high sensitivity and specificity for pneumonia-related features. It outperforms CXR in detecting small-volume consolidations and effusions, supporting its routine use in clinical settings.