Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The mediastinal and hilar contours are normal . The pulmonary vasculature is normal . There is a subtle opacity at the right base which could represent atelectasis or infection in the appropriate clinical setting . No pleural effusion or pneumothorax is seen .
    OUTPUT:
    
Subtle right basal opacity could represent atelectasis or infection in the appropriate clinical setting .