Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post sternotomy and probably coronary artery bypass graft surgery . The cardiac , mediastinal and hilar contours appear unchanged . The right lung remains clear . There is again a moderate to large pleural effusion on the left with associated opacities they can probably be attributed to a atelectasis , with a very similar appearance . There has been no definite change .
    OUTPUT:
    
Unchanged left - sided pleural effusion .