Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is mild enlargement of the cardiac silhouette . The hilar and mediastinal contours are unremarkable , except for mild prominence of the azygos vein . The lungs are well expanded and clear , without consolidation , or pneumothorax . A small left pleural effusion is present .
    OUTPUT:
    
Mild central vascular congestion , without evidence of edema .