Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to the prior study , the cardiomediastinal silhouette is probably unchanged , but remains enlarged . On the current exam , there is slightly increased cephalization of vessels and probably slight increase in the degree of opacity at the right lung base . No gross effusion . The azygos vein remains enlarged .
    OUTPUT:
    
1 . Cardiomegaly , without significant change . The possibility of associated pericardial fluid can not be excluded . 2 . Persistence azygos enlargement suggesting right heart failure . 3 . Upper zone redistribution and vascular plethora slightly more pronounced . Subtle confluent opacity may now be present at the right base . No air bronchograms or frank consolidation is identified . No effusions detected .