IMPRESSION:
PA and lateral chest compared to :
 
 Relatively small region of peribronchial opacification at the right lung base
 in the setting of above baseline vascular engorgement is probably mild edema. 
 Radiographically one cannot exclude recent aspiration or even very early
 pneumonia, but mild heart failure is the most likely explanation, given that
 heart size though normal is larger than it was in .  There is no pleural
 effusion, however, and the upper lungs are really clear.