Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy . Heart is upper limits of normal in size , and mediastinal and hilar contours are normal . Persistent left lower lobe atelectasis but improvement in right basilar atelectasis and apparent decrease in size of bilateral pleural effusions , which are now small , left greater than right .
    OUTPUT:
    
Decreased pleural effusions and improved aeration at right lung base .