Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Chest , portable . There is subtle opacity in the left lower lung . The lungs are otherwise clear . The hilar and cardiomediastinal contours are normal . There is no pneumothorax or pleural effusion . Pulmonary vascularity is normal .
    OUTPUT:
    
Subtle opacity in the left lower lung may represent atelectasis , but early pneumonia can not be fully excluded . Consider obtaining lateral film and / or close interval followup if there is high clinical suspicion for pulmonary infection .