Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: In comparison to the prior radiograph performed yesterday afternoon , opacification of the right hemithorax appears to have improved slightly . This suggests better aeration of the right lung . However , there is still a substantial right pleural effusion due to underlying empyema . Small air collection at the right costophrenic sulcus that is contiguous with extrathoracic space , s / p Eloesser flap . There is also a small left pleural effusion . Otherwise , the left lung is essentially clear . Stable cardiomediastinal silhouette .
    OUTPUT:
    
Slightly improved right lung aeration , suggesting some underlying atelectasis . However , there is persistent substantial opacification of right hemithorax likely due to empyema .