Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are extremely low , which causes crowding of the bronchovascular structures . Bilateral lower lobe opacities most likely represent atelectasis . Cardiac and mediastinal contours are likely normal . No free intraperitoneal air .
    OUTPUT:
    
Markedly low lung volumes . Bilateral lower lobe opacities most likely represent atelectasis ; however , infection can not be excluded . No free intraperitoneal air .