FINDINGS:
The patient is status post median sternotomy again with a top
 normal-sized cardiac silhouette and mildly tortuous thoracic aorta.  Hilar
 contours are unremarkable.  Lung volumes are low with right base atelectasis
 as well as increased focal retrocardiac opacity with lateral posterior lower
 lobe correlate.  Right-sided Port-A-Cath is again demonstrated terminating at
 the cavoatrial junction.  There is no pleural effusion or pneumothorax.  There
 is no overt pulmonary edema. Calcified mediastinal lymph nodes are again
 noted.

IMPRESSION:
Low lung volumes with a focal retrocardiac opacity with lower
 lobe correlate on lateral view.  This may represent either atelectasis or
 infection, and correlation with clinical presentation is recommended.