Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are low . The cardiac , mediastinal and hilar contours appear stable . There is a patchy new retrocardiac opacity in the left lower lobe that is best depicted on the frontal view concerning for pneumonia . Lungs appear elsewhere clear . There is no pleural effusion or pneumothorax . Bony structures are unremarkable .
    OUTPUT:
    
Findings suggest pneumonia in the left lower lobe .