FINDINGS:
Cardiac silhouette size is likely within normal limits.  The mediastinal and
 hilar contours are unremarkable, and no pulmonary edema is present.  A large
 left pleural effusion is present along with compressive atelectasis of the
 left lung base.  The right lung is clear.  No pneumothorax is identified. 
 There are mild degenerative changes seen in the thoracic spine.

IMPRESSION:
Large left pleural effusion with compressive left basilar atelectasis.