Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The large right pleural effusion with associated atelectasis has slightly decreased . The upper right lung field and left lung remain clear . There is no pneumothorax . The heart and mediastinum can not be accurately assessed , although the heart size remains appears slightly smaller today . Previous mild pulmonary edema has also decreased .
    OUTPUT:
    
Slightly decreased large right pleural effusion with associated atelectasis . Decreased mild pulmonary edema .