Lung ultrasound vs. chest X-ray in children with suspected pneumonia confirmed by chest computed tomography: A retrospective cohort study

The chest X-ray is routinely requested by pediatricians for children with suspected pneumonia, but has been demonstrated to be an insensitive method with relatively low accuracy. Computed tomography (CT) allows for the characterization of the consolidation in pneumonia but has a high risk of radiation exposure in children. Lung ultrasonography can identify subpleural lung consolidation in adults, but it is not accepted in routine clinical practice and is also not used for the diagnosis of children with pneumonia. The objective of the present study was to compare diagnostic parameters of lung ultrasound with chest X-ray in children with suspected pneumonia, using CT as a reference standard. Medical records of 949 children, aged ≤16 years, with suspected pneumonia were reviewed. Data regarding the chest radiograph, lung ultrasound and chest CT were collected and analyzed. Beneficial score analysis for each diagnostic modality was evaluated according to the pneumonia severity index. The chest radiograph successfully detected subpleural lung consolidation and dense lung opacity. The lung ultrasound successfully detected pleural effusion and perilesional inflammatory edema. The chest CT successfully detected a liquefied area, enhancement and necrosis of the lungs. Compared with the chest CT, the lung ultrasound displayed 0.906 sensitivity and 0.661 accuracy, while the chest radiograph displayed 0.793 sensitivity and 0.559 accuracy. For a pneumonia severity index of <3, the chest CT displayed a good beneficial score, followed by the lung ultrasound and chest radiograph. In conclusion, lung ultrasound is a non-invasive and simple method that could be used for the diagnosis of suspected pneumonia in children.