Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . Mediastinal and hilar contours are unremarkable . Pulmonary vasculature is normal . Mild atelectasis is seen in both lower lobes without focal consolidation , pleural effusion or pneumothorax . No acute osseous abnormalities are present . Clips are noted projecting over the left superior mediastinum at the thoracic inlet , compatible prior parathyroid surgery . Cholecystectomy clips are also seen within the upper abdomen .
    OUTPUT:
    
Mild bibasilar atelectasis .