Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . Cardiomediastinal silhouette and hilar contours are unremarkable . Seen only on lateral view , in the posterior lung base , there is subtly increased opacity which may reflect infection . Lungs appear clear on frontal view . Pleural surfaces are clear without effusion or pneumothorax .
    OUTPUT:
    
Subtle opacity in the posterior lung base seen on lateral view only , which may represent pneumonia .