Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is mild bibasilar atelectasis . As on the prior study the left hemidiaphragm is elevated with mild gaseous distension of bowel underneath . There is no convincing evidence of pneumonia . Heart size is normal . The mediastinal and hilar contours are unremarkable . There is no pleural effusion or pneumothorax . There are three healed right upper rib fractures .
    OUTPUT:
    
Mild bibasilar atelectasis . Persistent elevation of the left hemidiaphragm . No convincing evidence of pneumonia .