Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single left chest tube . Left pleural effusion has significantly decreased since prior . Left basilar opacity has significantly improved . Mildly more prominent right basilar opacity , atelectasis versus pneumonia . No pneumothorax . Shallow inspiration accentuates heart size , pulmonary vascularity . Postoperative changes right shoulder .
    OUTPUT:
    
Improvement since prior .