Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal and hilar contours are normal . Subtle right perihilar opacity , is new since the prior study and is concerning for an early infection . Linear atelectasis is seen in the left lung base . No pleural effusion or pneumothorax is detected .
    OUTPUT:
    
Right perihilar pneumonia . Follow up radiographs after treatment is recommended to ensure resolution .