Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to the prior study , the degree of upper zone redistribution is increased , which could reflect early / mild CHF . Otherwise , the overall appearance is similar . Patchy opacity at both lung bases and minimal blunting of the right costophrenic angle is similar . Cardiomediastinal silhouette is unchanged . Sternotomy wires and mediastinal clips noted .
    OUTPUT:
    
New upper zone redistribution suggests early changes of CHF . Mild patchy opacity at both bases is unchanged . The appearance is compatible with atelectasis , though early pneumonic infiltrates would be difficult to completely exclude . Small right effusion is unchanged .