Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette is mildly enlarged . Hilar contours are normal . A subtle retrocardiac opacity is worrisome for infection . Biapical hyperlucency is compatible with emphysema . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
1 . Subtle retrocardiac opacity worrisome for infection . Follow up chest radiograph to trace resolution is recommended . 2 . Emphysema . Results were discussed over the telephone with Dr . ___ by ___ at 15 :33 on ___ at time of initial review .