Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to the prior radiograph from late ___ , perihilar heterogeneous opacities are persistent with slight interval improvement . No pleural effusion or pneumothorax . Right chest wall port and catheter are unchanged .
    OUTPUT:
    
Persistence of bilateral perihilar opacities which are slightly improved , but indicate ongoing infection .