Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Allowing for technical differences , the cardiomediastinal silhouette is probably unchanged . There is upper zone redistribution and increased interstitial markings , more pronounced in the right lung , though with relative sparing of the left upper zone . There is atelectasis and / or scarring at the right lung base . There is minimal blunting of the right costophrenic angle , similar to the prior film .
    OUTPUT:
    
1 . Increased interstitial markings right - greater - than - left . Possible slight improvement in the left upper and mid zones . In the appropriate clinical setting , this could reflect the presence of CHF , but the differential diagnosis includes other interstitial processes . Of note , the ___ chest CT shows evidence for chronic changes in lung that could contribute to this appearance . 2 . No frank alveolar opacity . No gross effusion . 3 . The opacity at the right base is somewhat more confluent -- probable atelectasis , but an early pneumonic infiltrate can not be entirely excluded .