The Prevalence of Pneumonia in Children under 15 Years of Age Who Have Air Bronchogram Sign on Chest Computed Tomography Studies

OBJECTIVE The aim of the study was to investigate the prevalence of pneumonia in the presence of air bronchogram on chest computed tomography (CT) according to pediatrician’s concerning about the presence of air bronchogram in favor of pneumonia in children under 15 years of age. METHODS A total of 371 children under 15 years of age who had air bronchogram on chest CT studies from January 2015 to December 2019 in Siriraj Hospital were included, of which 182 cases had been diagnosed with pneumonia. CT analysis was conducted, including identification of the location of air bronchograms, consolidation, atelectasis, interstitial infiltration, ground glass opacity (GGO), pleural effusion, bronchiectasis, lymphadenopathy, cardiomegaly, lung abscess and nodules and findings were determined by consensus of an experienced pediatric radiologist and an in-training resident. RESULTS The prevalence of pneumonia in this group was 49.1% and that of atelectasis was 68.2%. Air bronchograms in consolidation, especially at the right lower lobe, were more likely associated with pneumonia. Air bronchograms in atelectasis were more likely associated with non-pneumonia conditions. Air bronchogram sign in consolidation combined with GGO, pleural effusion or bronchiectasis in union pattern were associated with an increased incidence of pneumonia of 69.2%, 67.1% and 74.6%, respectively. CONCLUSIONS The presence of air bronchograms is not specific for pneumonia. Air bronchograms were found more frequently in atelectasis than in pneumonia (68.2% vs. 49.1%). Although air bronchogram in consolidation should raise concerns for lesions in both pneumonia and non-pneumonia cases, the combination of air bronchogram in consolidation with additional GGO, pleural effusion and bronchiectasis is associated with an increased likelihood of pneumonia.