Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are diminished . The cardiac silhouette is stably enlarged . There is no definite pleural effusion or pneumothorax . Though no definite consolidation is identified , there is a more prominent retrocardiac opacity than previously identified likely due to lower lung volumes .
    OUTPUT:
    
More prominent retrocardiac opacity than previously identified likely due to lower lung volumes . Lower lobe pneumonia not entirely excluded .