Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright view of the chest . Mild basilar atelectasis is noted without definite signs of pneumonia or CHF . No large effusion or pneumothorax . Cardiomediastinal silhouette is normal . Bony structures are intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
Mild bibasilar atelectasis .