Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a persistent ill - defined area of increased density in the left infrahilar region . The lungs appear otherwise clear . The heart is normal in size . Mediastinal structures are otherwise unremarkable . The bony thorax is grossly intact .
    OUTPUT:
    
Persistent sidewall left lower lobe opacity concerning for pneumonia . No definite change .