Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Re demonstrated is a large hiatal hernia . There has been an interval increase in opacification at the left lung base . There is mild pulmonary vascular congestion . There is no pneumothorax . The visualized osseous structures are unremarkable .
    OUTPUT:
    
Opacification at the left lung base , likely secondary to pneumonia . Stable large hiatal hernia and vascular congestion .