Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is normal in size . The mediastinal and hilar contours appear within normal limits . There is no pleural effusion or pneumothorax . There is a patchy new posterior left lower lobe opacity obscuring the posterior margin of the left hemidiaphragm but also visible faintly on the frontal view as a retrocardiac opacity . Elsewhere , the lungs appear clear .
    OUTPUT:
    
Findings consistent with pneumonia in the left lower lobe .