FINDINGS:
Heart size is normal with mildly tortuous thoracic aorta.  Hilar
 contours are unremarkable.  There is a subtle increased density in the
 posterior lower lung fields on lateral view only without frontal correlate
 which could represent atelectasis or a subtle pneumonia.  There is no pleural
 effusion or pneumothorax.

IMPRESSION:
Slightly increased density in the lower posterior lung field on
 lateral view only, which is likely atelectasis; however, infection is not
 excluded given the correct clinical circumstance.