Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are low . The cardiac , mediastinal and hilar contours appear unchanged . Minimal opacity at each lung base is suggestive of atelectasis but improved . The lateral view in particular depicts a patchy posterior right basilar opacity , probably improved since the prior radiographs . There is no pleural effusion or pneumothorax . There is no free air . Degenerative changes are moderately severe at each shoulder , but incompletely imaged or characterized . The patient is status post lower anterior cervical fusion , also not entirely characterized .
    OUTPUT:
    
Decreased opacities at both lung bases .