Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded . A retrocardiac opacity is better seen in the lateral view . There is also apparent engorgement of the right hilum of unclear significance but hilar adenopathy can not be completely excluded . The heart is moderately enlarged . There is no pleural effusion pneumothorax .
    OUTPUT:
    
Retrocardiac opacity suggestive of left lower lobe pneumonia . Right hilar engorgement and upper zone redistribution may be secondary to vascular congestion in the setting of cardiomegaly .