Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Chest , PA and lateral . There is a possible small left pleural effusion and there are bilateral lower lobe opacities . The lungs are otherwise clear . The heart size is top normal or slightly enlarged . Probable background hyperinflation . No CHF . There is no pneumothorax .
    OUTPUT:
    
Bibasilar opacities , likely atelectasis . An early infiltrate would be difficult to exclude . Possible small left pleural effusion .