Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are slightly lower compared to the prior exam . Edema has improved . No pleural effusion or definite focal consolidation . Retrocardiac opacity in streak like opacities in the left lower lobe are most likely atelectasis . The heart is mild - to - moderately enlarged . The mediastinum is not widened .
    OUTPUT:
    
Interval improvement in edema . Persistent left lower lobe atelectasis .