Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single upright portable view of the chest demonstrates hyperexpansion of the lungs with flattening of the hemidiaphragms , as before , with slight interval increase in bibasilar opacities , possibly atelectasis or aspiration or infection . The heart and cardiomediastinal silhouette are unchanged . No pleural effusion or pneumothorax is detected .
    OUTPUT:
    
Bibasilar opacities , possibly atelectasis ; however , aspiration or infection can have a similar appearance .