Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single AP portable upright view of the chest is provided . The patient appears rotated . Lung volumes remain low and bibasilar opacities probably represent atelectasis . There is no focal consolidation , large pleural effusion , or pneumothorax . The cardiomediastinal contour is stable .
    OUTPUT:
    
Persistent low lung volumes and basilar atelectasis .