1. Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
2. Department of Ultrasound, China-Japan Friendship Hospital, China Beijing;
3. Institute of Clinical Medicine, China-Japan Friendship Hospital, Beijing, China
4. Capital Medical University, Beijing, China
5. Department of Ultrasound, China-Japan Friendship Hospital, National Center for Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, Institute of Respiratory Medicine of Chinese Academy of Medical Sciences, Beijing, China