The chest x-ray shows features of left main bronchus foreign body.
There is hyperlucency & oligaemia of the left lung field on 1st chest x-ray image. The expiratory view shows hyperinflation & hyperlucency of the left lung field & asymmetric lung field (L> R).
The patient underwent an urgent bronchoscopy which revealed a peanut obstructing the left main bronchus.
Inhaled foreign bodies are mostly organic and hence will not show up on the x-rays. One must learn to look for indirect signs of inhaled foreign body in children. Chest x-ray can be normal in paediatric inhaled foreign bodies and if in doubt, patient should be referred to respiratory specialist for bronchoscopy.
Further reading https://www.eurorad.org/case/5742