Predictive power of chest radiography for infectious or inflammatory lung disease

Abstract Objective Children frequently present with chronic cough, recurrent respiratory infections, and dysphagia. These symptoms are poor predictors of significant inflammatory lung disease, such as from chronic aspiration. Bronchoalveolar lavage (BAL) is the gold standard for identification of lung infection and airway inflammation but is expensive and requires sedation. Chest X‐rays (CXR) are inexpensive, low‐radiation tests that do not require sedations and can document findings associated with infectious or inflammatory lung disease. The accuracy of CXR to predict or exclude infectious or inflammatory lung disease has not been directly evaluated and is unknown. Methods Retrospective cohort of all pediatric patients who underwent FFB with BAL within 2 weeks of a CXR. Blinded CXR images reviewed for findings consistent with inflammatory disease by two senior pediatric radiologists. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for CXR to identify significant inflammation and/or infection on BAL were calculated. Results Three hundred and forty‐four subjects included. Two hundred and sixty‐three had positive CXR (77%), 183 had inflammatory BAL (53%), and 110 had infection (32%). The sensitivity of CXR changes for BAL inflammation, infection, and either inflammation or infection was 84.7, 90.9, and 85.3, respectively. The PPV of CXR was 58.9, 38.0, and 59.7. The NPV of CXR was 65.0, 87.5, and 66.3. Conclusions Although CXR are inexpensive, do not require sedation, and are of low radiation dose, the ability of an entirely normal CXR to exclude active inflammatory or infectious lung disease is limited.