Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph was obtained . The lungs are hyperinflated which is suggestive of underlying COPD . There is no definite evidence of pneumonia or overt CHF . There is mild left basilar opacity which could represent atelectasis . The heart is moderately enlarged . Mediastinum is normal . No pneumothorax . Bony structures are intact .
    OUTPUT:
    
COPD with left basal opacity which could represent atelectasis . Please refer to subsequent CT chest for further details .