School ager who started coughing after eating peanuts

CXR of peanut in left mainstem bronchus
Inspiratory CXR AP (left) is normal and shows the lungs to be clear and to be symmetrically aerated and no radiopaque foreign body is seen. Expiratory CXR AP (right) shows a normal decrease in the volume in the right lung in expiration while there is no decrease in the volume in the left lung in expiration (air trapping) and there is mediastinal shift to the right.

The diagnosis was airway foreign body in the form of a peanut in the left mainstem bronchus.