Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size remains mildly enlarged . The mediastinal and hilar contours are unremarkable . The pulmonary vasculature is normal . Minimal patchy bibasilar opacities likely reflect atelectasis . No focal consolidation , pleural effusion or pneumothorax is demonstrated . There are no acute osseous abnormalities . Mild degenerative changes are noted in the thoracic spine .
    OUTPUT:
    
Mild bibasilar atelectasis .