FINDINGS:
There is left-sided volume loss with an increased pleural effusion when
 compared with . Retrocardiac atelectasis has also increased, and
 superimposed pneumonia cannot be ruled out in the proper clinical setting.
 Evaluation is limited by the left scapula projecting over the the area of
 concern. Lateral views may also be helpful if clinically feasible. The right
 lung is clear. There is no pulmonary vascular congestion or pneumothorax. A
 surgical clip projects over the left tracheobronchial angle.

IMPRESSION:
Increasing left-sided pleural effusion, now moderate with adjacent compressive
 atelectasis.  Superimposed pneumonia is possible in the proper clinical
 setting.