Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal silhouette is enlarged , but unchanged . There is upper zone redistribution without overt CHF . As before , there are bibasilar opacities . These may represent atelectasis , but increased opacity in the lower lobe on the lateral view acute difficult to exclude a pneumonic infiltrate . Allowing for technical differences , the appearance is probably slightly improved compared with ___ . No pleural effusion is identified . Degenerative changes of the thoracic spine are incidentally noted .
    OUTPUT:
    
1 . Cardiomegaly and upper zone redistribution , similar to the prior film . No overt CHF and no effusion . 2 . Bibasilar opacities . Associated pneumonic infiltrate or focus of aspiration would be difficult to exclude .