Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours are normal . The pulmonary vasculature is normal . Subtle patchy opacity is noted within the left lung base laterally . The right lung is clear . No pleural effusion or pneumothorax is identified . No acute osseous abnormalities seen .
    OUTPUT:
    
Subtle patchy opacity within the left lateral left lung base , which could reflect an area of infection .