Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph is obtained . No definite amount of free air below the right hemidiaphragm . Vague bibasilar opacities likely reflect atelectasis . Otherwise , the lungs are clear . Cardiomediastinal silhouette is normal . Bony structures are intact .
    OUTPUT:
    
No definite signs of pneumoperitoneum . Bibasilar atelectasis .