Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . Subtle lucency near the aortic knob is not well localized on this portable exam and could reflect focal pneumomediastinum or a small medial pneumothorax . Lungs are clear except for patchy bibasilar opacities , left greater than right . . The heart is normal in size . The thoracic aorta is tortuous and / or ectatic . Subtle cortical discontinuity in left lateral ___ and 6th ribs may reflect non-displaced fractures of indeterminate age . No unexplained radiopaque foreign body .
    OUTPUT:
    
1 . Subtle lucency knear aortic knob , potentially representing focal pneumomediastinum or small medial pneumothorax . . 2 . Bibasilar opacities , likely atelectasis although contusion and aspiration are additional considerations .