FINDINGS:
The lung volumes are low.  The cardiac, mediastinal and hilar
 contours appear stable.  There is a patchy new retrocardiac opacity in the
 left lower lobe that is best depicted on the frontal view concerning for
 pneumonia.  Lungs appear elsewhere clear.  There is no pleural effusion or
 pneumothorax.  Bony structures are unremarkable.

IMPRESSION:
Findings suggest pneumonia in the left lower lobe.