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 . Subtle opacity involving the right middle lobe may represent an area of infection . No pleural effusion or pneumothorax is seen . A nodular density is seen in the mid , left lower lobe is consistent with known mass , better characterized on prior PET - CT . As before there are streaks of fibrosis seen in the bilateral lungs consistent with posttreatment changes .
    OUTPUT:
    
Subtle opacity involving the right middle lobe may represent an early focus of infection . Short - term followup radiographs may be helpful in this regard . .