Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The mediastinal and hilar contours are normal . The pulmonary vasculature is normal . Lung volumes are low with mild bibasilar atelectasis , but no focal consolidation . No pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities . No subdiaphragmatic free air is visualized . Clips are seen in the right upper quadrant of the abdomen compatible with prior cholecystectomy .
    OUTPUT:
    
Mild bibasilar atelectasis . No subdiaphragmatic free air .