Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post coronary artery bypass graft surgery . A right - sided pacemaker device has been placed , terminating in the right ventricle . There is a moderate pleural effusion on the left with associated opacity , probably due to atelectasis , including volume loss and mild leftward shift of mediastinal structures . Aside from streaky and band - like opacities in the right lower lung suggesting minor atelectasis , the right lung appears clear . There is no pleural effusion of the right or pneumothorax . There is no definite evidence for free air .
    OUTPUT:
    
Moderate left - sided pleural effusion with substantial suspected atelectasis . No evidence for free air .