Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A subtle opacity seen at the right lung base . There is mild enlargement of the pulmonary arteries . There is no evidence pneumothorax . The heart size is normal . The hilar and mediastinal contours are otherwise unremarkable . The visualized osseous structures are unremarkable .
    OUTPUT:
    
Subtle opacity at the right lung base concerning for an infectious process .