Introduction

Pneumonia is one of the most common serious infections of childhood. Plain chest radiographs remain the diagnostic mainstay in childhood pneumonia and chest computed tomography (CT) is rarely required in immunocompetent children presenting with symptoms and signs typical of chest infection. The appearance of different kinds of the childhood pneumonia is well established and fully described in the early literature of 1970s and 1980s. Since then, there is no significant further update on the radiographic aspects of childhood pneumonia. The relatively old references are therefore omitted in this chapter.

The major indication of chest radiograph in children presenting with chest infection is to confirm or exclude the presence of pneumonia. A follow-up chest X-ray is not routine in the management of children who have uneventful recovery, as postobstruction pneumonia (secondary to pulmonary carcinoma), which occurs in adults, is not a concern in paediatric age group.

The other indications of imaging, including CT, in children presenting with chest infections are:

• to predict or suggest the nature of the infectious agent;

• to look for any underlying developmental anomaly that predisposes a child to persistent or recurrent pneumonia;

• to assess acute complications and to guide management;

• to evaluate the sequelae of respiratory infection.

Chest X-ray and common infective agents

The common aetiological agents that cause lower respiratory tract infection in children vary with age.