FINDINGS:
The heart is normal in size.  The left atrial appendage is perhaps
 somewhat prominent, noting a mildly convex contour to the left mid
 mediastinum.  There is no pleural effusion or pneumothorax.  Best seen on the
 lateral view is a patchy opacity projecting over the lower spine.  Although it
 overlaps with the course of the left hemidiaphragm, it does not silhouette the
 the hemodiaphragm, so it seems perhaps more likely to reside in the right than
 left lower lobe.  Bony structures are unremarkable.

IMPRESSION:
1.  Patchy posterior basilar opacity, most likely in the right lower lobe,
 suggesting pneumonia, although the side is not entirely certain.  
 
 2.  Mildly bulging left mid mediastinal contour, suggesting enlargement of the
 left atrial appendage.  Other etiologies could yield this contour too, such as
 a thymic cyst.  Correlation with prior films may be helpful if available
 clinically.