Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . There are midline sternotomy wires from prior CABG . The aorta is calcified , indicating atherosclerosis . The mediastinal and hilar contours are normal . The pulmonary vasculature is normal . Low lung volumes . Bibasilar atelectasis . Lungs are clear . No pleural effusion or pneumothorax is seen . There are cholecystectomy clips .
    OUTPUT:
    
Bibasilar atelectasis . No radiographic evidence of pneumothorax .