FINDINGS:
In the left perihilar region, there is a hazy opacification
 consistent with pneumonia.  There is no pulmonary edema, pleural effusion, or
 pneumothorax.  The cardiomediastinal silhouette is normal.  There is elevation
 of the left hemidiaphragm, which is stable from the prior exam.

IMPRESSION:
Left perihilar pneumonia.  Recommend followup radiographs after
 treatment to ensure resolution.