FINDINGS:
There is increased retrocardiac opacity with air bronchograms new
 from , with additional subsegmental linear atelectasis at the left
 base.  The cardiac silhouette remains top normal, the mediastinal contours are
 normal.  There is no pneumothorax or significant effusion.

IMPRESSION:
New retrocardiac opacity which is concerning for pneumonia, and
 could be better evaluated with dedicated upright and lateral chest
 radiographs.