Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since prior examinations there is little change . There is persistent elevation of the right hemidiaphragm . There are scattered areas of bibasilar atelectasis . The cardiomediastinal and hilar contours are stable demonstrating changes related to prior CABG . Heart size is normal . Pulmonary vascularity is normal . There are no pleural effusions . There is no pneumothorax . There is a trace left pleural effusion .
    OUTPUT:
    
No evidence of pneumonia .