Accuracy of Lung Ultrasonography versus Chest Radiography for the Diagnosis of Community Acquired Pneumonia in Children: A Cross-sectional Study

Abstract

Introduction: Pneumonia is one of the most common causes of childhood morbidity and mortality, which warrants a proper diagnosis and adequate treatment. Early diagnosis of Community Acquired Pneumonia (CAP) is essential to reduce the total burden of this disease. Aim: To evaluate the diagnostic accuracy of Lung Ultrasound (LUS) in CAP in children as compared to Chest Radiograph (CXR). Materials and Methods: This was a cross-sectional study involving 91 subjects with clinically suspected pneumonia, who underwent US examination in the Department of Radiodiagnosis, Government Medical College, Thrissur, Kerala, India from December 2018 to December 2019. LUS was done to obtain information regarding different patterns of presentation of pneumonia. Although Computed Tomography (CT) is considered the gold standard imaging for pneumonia, it is used only for complicated pneumonia and is not routinely performed in the paediatric age group as radiation exposure will be more than that of the CXR. Hence, a CXR was taken as a reference standard in this study, and findings of LUS were compared. The data was managed using Microsoft Excel 2016 and statistical analysis was done with International Business Machines (IBM) Statistical Package for the Social Sciences (SPSS) version 27.0. The sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV), and accuracy were calculated. Results: Overall, LUS had a sensitivity of 95.83%, a specificity of 93.02%, a PPV of 93.88%, a NPV of 95.24%, and an accuracy of 94.5% (p<0.001) as compared to CXR which had a sensitivity of 93.8%, specificity of 95.23%, the PPV of 95.80%, the NPV of 93.0% and accuracy of 95%. Substantial agreement between LUS and a CXR was found, for diagnosing specific patterns of CAP with Cohen’s Kappa value of 0.74. Conclusion: LUS offers an important contribution to the diagnosis of pneumonia in children as compared with a CXR. With its high NPV, it can replace CXR in order to exclude lung consolidation in children, thus reducing radiation exposure in this population.