Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes and portable technique limit evaluation . Bibasilar opacities may be secondary to atelectasis . Superiorly , the lungs are clear . The cardiomediastinal silhouette is stable . No acute osseous abnormalities , old right posterior rib fractures noted .
    OUTPUT:
    
Bibasilar opacities , potentially atelectasis