Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are hyperexpanded , with marked hyperlucency at the upper zones , reflecting severe COPD . Ground - glass opacities at the bilateral lower lungs have worsened since ___ . There is no pneumothorax or pleural effusion . The heart size is normal . The hilar and mediastinal contours are within normal limits . The central pulmonary vessels are normal in caliber .
    OUTPUT:
    
Worsening bibasilar opacities in the setting of severe COPD , compatible with infection . Edema is unlikely given lack of central pulmonary vascular congestion .