Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lungs are hyperinflated , suggesting COPD . Heart size is at the upper limits of normal or slightly enlarged . No CHF . Minimal subsegmental atelectasis and / or scarring seen at the left lung base . No focal infiltrate or gross effusion identified . No pneumothorax detected .
    OUTPUT:
    
No CHF , focal infiltrate or gross effusion . Probable background COPD . Heart size borderline enlarged .