Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes remain low . The right PICC tip terminates at the cavoatrial junction . Heart size remains mildly enlarged , and is accentuated by the low lung volumes . Mediastinal contours are unchanged . There is crowding of the bronchovascular structures as a result of low lung volumes with probable mild pulmonary vascular engorgement . Bibasilar opacities appear progressed compared to the prior exam , and may reflect worsening atelectasis though infection is not excluded . Small left pleural effusion persists . No pneumothorax is identified .
    OUTPUT:
    
Low lung volumes with probable mild pulmonary vascular congestion and worsening bibasilar opacities , likely atelectasis . Infection however is not excluded . Small left pleural effusion , unchanged .