This is a case of respiratory distress syndrome in twin infants.

Initial radiographs is of low volume appearance due to alveolar atelectasis (secondary to surfactant deficiency). Later air bronchograms can be seen.

The radiologist must be aware that :

1. post intubation the lung fields appear hyper-inflated and complications such as pulmonary hemorrhage or pneumothorax can occur. 

2. when surfactant is administered via endotracheal tube, the opacities appear quite asymmetric and non homogenous.