Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are hyperinflated suggesting COPD . There is new retrocardiac opacification localized to the left lower lobe on the lateral , which represents pneumonia . The lungs are otherwise clear . Heart size is normal . The mediastinal and hilar contours are normal . The pulmonary vasculature is normal . No pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Left lower lobe pneumonia .