FINDINGS:
Frontal and lateral views of the chest were obtained.  There are
 low lung volumes, slightly lower than that seen on the prior study. 
 Retrocardiac opacity persists.  The patient had somewhat linear retrocardiac
 opacity in the prior chest radiograph performed on , which may
 represent chronic atelectasis/scarring, however, the retrocardiac opacity
 today appears more confluent, although not optimally evaluated given low lung
 volumes.  Findings could be due to atelectasis, infection, or even aspiration.
 Prior chest CT performed on , he had a small hiatal hernia at that
 time, although no cross-sectional imaging of this in the interval.  Slight
 patchy opacity superior to the minor fissure and along the right mid lung
 could be due to mild pulmonary vascular congestion or atelectasis; given the
 short-term interval development, infection is less likely.