Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There has been interval placement of a tracheostomy tube . Lung volumes are low resulting in vascular crowding and bibasilar atelectasis . The cardiomediastinal silhouette is unchanged . There is no pneumothorax , pneumomediastinum , pleural effusion , or pulmonary edema .
    OUTPUT:
    
Bibasilar atelectasis in the setting of low lung volumes without evidence of pneumomediastinum or pneumothorax .