Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy . The cardiac and mediastinal silhouettes are grossly stable . Lateral left mid to lower lung opacity which may represent small chronic pleural effusion , adjacent atelectasis and scarring . No pneumothorax is seen . No definite new focal consolidation is seen .
    OUTPUT:
    
No significant interval change .