Imaging description

This previously healthy 10-month-old infant presented with coughing and wheezing. The frontal chest radiograph demonstrated subtle hyperlucency of the right lung compared to the left side (Fig. 14.1a).

Right and left lateral decubitus views of the same child (Fig. 14.1b, c) show that the left lung inflates and deflates normally in the up and down position respectively, while the right lung field does not change due to air trapping on that side. A right mainstem foreign body was diagnosed and food material was removed at a subsequent bronchoscopy.

Importance

Endobronchial foreign body aspiration most often occurs in children between the ages of one and three years. Peanuts, seeds, and beans are the most common foreign bodies aspirated.

Since most endobronchial foreign bodies are radiolucent (80%), the foreign object itself is rarely visible radiographically (Fig. 14.2); therefore, diagnosis based on imaging often depends on the secondary effects produced by the foreign body (Fig. 14.1). If an inhaled foreign body is suspected, inspiratory/expiratory films (in a cooperative child) or lateral decubitus films (in a child unable to hold his/her breath) are useful in aiding in the detection of air trapping of the affected lung (Fig. 14.1b, c).