Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There appears to be a retrocardiac opacity , new since the prior study , best seen on the lateral view . The heart is moderately enlarged . There is moderate pulmonary vascular congestion . Tortuosity of the thoracic aorta is again noted . There no pleural effusion or pneumothorax . Median sternotomy wires are present .
    OUTPUT:
    
Retrocardiac opacity concerning for pneumonia in the appropriate clinical setting .