Background: Opinions differ as to the need of a lateral radiograph for diagnosing community acquired pneumonia in children referred to the emergency department. A lateral radiograph increases the ionizing radiation burden but at the same time may improve specificity and sensitivity in this population.

Objectives: To determine the value of the frontal and lateral chest radiographs compared to frontal view stand-alone images for the management of children with suspected community acquired pneumonia seen in a pediatric emergency department.

Methods: Chest radiographs from 451 children with clinically suspected pneumonia were retrospectively reviewed. Interpretation of frontal views was compared to interpretation of combined frontal and lateral view, the latter being the gold standard.

Results: Findings consistent with bacterial pneumonia were diagnosed in 94 (20.8%) of the frontal stand-alone radiographs and in 109 (24.2%) of the combined frontal and lateral radiographs. The sensitivity, specificity, positive predictive value, and negative predictive value of the frontal radiograph alone were 86.2%, 93.9%, 81.7%, and 95.5%, respectively. False positive and false negative rates were 15% and 21%, respectively, for the frontal view alone. The number of lateral radiographs needed to diagnose one community acquired pneumonia was 29.

Conclusions: The lateral chest radiograph improves the diagnosis of pediatric community acquired pneumonia to a certain degree and may prevent overtreatment with antibiotics.