In children the following are the most common chest X-ray (radiographic) features:
- The site of the primary infection in the lung cannot usually be seen on a chest X-ray. However, the associated hilar lymphadenopathy (enlarged lymph nodes where the main bronchi enter the lung) is seen, often with widening of the mediastinum. A lateral chest X-ray will make it easier to see hilar adenopathy.
- The enlarged hilar lymph nodes may partially or completely compress a bronchus resulting in an area of over-expansion (air trapping), collapse or consolidation.
- Miliary tuberculosis presents with multiple small spots (nodular pattern) evenly spread through both lungs.
- A pleural effusion, especially in older children.
- A cavity may form within the area of pneumonia, especially in adolescents. This is usually seen in the upper lobes of the lungs.
In young children the interpretation of a chest X-ray may be difficult. A good chest X-ray is important to both diagnose tuberculosis and monitor the response to treatment. Some children with tuberculosis may have a normal chest X-ray, e.g. infants with tuberculous meningitis, bone tuberculosis or any other form of extrapulmonary tuberculosis.