FINDINGS:
2 views were obtained of the chest.  Left upper lobe opacification
 with accompanying volume loss and resultant leftward shift of the mediastinum
 is noted and suggestive of lingular or segmental left upper lobe collapse. 
 The right lung is comparable a well-aerated.  There is no pleural effusion or
 pneumothorax.  The heart size appears normal though obscured by this opacity.

IMPRESSION:
Lingular or segmental left upper lobe collapse/atelectasis.  
 
 Consider mucous plugging or other cause of airway obstruction.  Consider
 repeat imaging after vigorous coughing or suctioning depending on the
 patient's clinical circumstance to see if this resolves.