IMPRESSION:
The patient is status post median sternotomy for CABG with expected
 postoperative cardiac and mediastinal contours.  There is a moderate amount of
 free air beneath the right hemidiaphragm.  Left hemidiaphragm is elevated and
 there is patchy opacity at the left base which may reflect atelectasis or
 chronic postoperative changes, although an acute infectious process cannot be
 excluded.  Clinical correlation is advised.  There is no evidence of pulmonary
 edema.  No pneumothorax.  Several surgical clips are seen in the left upper
 quadrant.  Streaky linear opacity at the right base most likely reflects
 atelectasis.  A portion of an aortic stent is visualized in the mid abdomen.