Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . Minimal opacities within the lung bases may reflect dependent atelectasis . The remainder of the lungs are clear . There is no pulmonary vascular congestion , edema , or large effusions . Apparent mediastinal widening is likely secondary to the AP technique . The heart size is normal .
    OUTPUT:
    
Mild bibasilar atelectasis . No pulmonary edema or pneumonia .