Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Median sternotomy is again noted . Cardiomediastinal silhouette is stable . Dense atherosclerotic calcifications are present in the aortic arch and throughout descending thoracic aorta . There increased retrocardiac opacification as compared to the prior examination which could represent pneumonia in the appropriate clinical context .
    OUTPUT:
    
Increased retrocardiac opacification could represent pneumonia in the appropriate clinical context .