Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . A replaced tracheostomy is noted in the expected position . No pneumothorax is seen . Mild bibasilar atelectasis is noted . Heart size is unchanged . There is no pulmonary edema .
    OUTPUT:
    
Replaced tracheostomy is seen in the expected location . No evidence of pneumothorax .