Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to prior examination , there has been interval removal of a left pleural pigtail drain . Again appreciated are bilateral moderate - to - large pleural effusions , which appear slightly increased in size with associated bibasilar volume loss . There is no pneumothorax . The osseous structures are grossly unremarkable .
    OUTPUT:
    
Bilateral moderate - to - large pleural effusion slightly increased from prior study .