Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral views of the chest were obtained . Subtle left lower lobe opacity , which could represent a very early pneumonia . Otherwise , the lungs appear clear . No large effusion or pneumothorax is seen . Cardiomediastinal silhouette appears stable . Bony structures appear intact . Partially imaged tubing in the bilateral upper abdomen likely reflect nephrostomy tubes .
    OUTPUT:
    
Subtle opacity in the left lower lobe could represent a very early pneumonia .