FINDINGS:
The lungs are hyperinflated reflective of COPD.  Apparent increased opacity
 projecting over the right lung apex correlates with posterior right fifth rib
 fracture with callus.  Streaky bibasilar opacities likely reflect atelectasis.
 There is a rounded retrocardiac opacity on the frontal view which likely
 corresponds to vague opacity in the posterior costophrenic angle on the
 lateral view.  There is no focal consolidation to suggest pneumonia.  There is
 no pleural effusion or pneumothorax.  The heart is normal in size, and the
 mediastinal contours are normal.  High density at the left hilum may represent
 calcified lymph node.

IMPRESSION:
No acute cardiopulmonary process.
 Focal rounded opacity in the retrocardiac region likely posteriorly on the
 lateral view which may correspond to a Bochdalek's hernia although not fully
 characterized.  Nonurgent CT suggested unless prior imaging performed
 elsewhere available to confirm.