Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post coronary artery bypass graft surgery and mitral valve replacement . The heart is mildly enlarged . The mediastinal and hilar contours appear within normal limits . A left - sided pleural effusion has decreased and is now small , perhaps with slight loculation . The lungs appear clear . There is no pneumothorax .
    OUTPUT:
    
Decreased left - sided pleural effusion . No evidence of pneumonia .