Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes . Heart size is at the upper limits of normal and unchanged . The mediastinal and hilar contours are unchanged . The pulmonary vasculature is normal . Mild bibasilar atelectasis . Lungs are otherwise clear . No pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Mild bibasilar atelectasis .