1. State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering; Chongqing Key Laboratory of Biomedical Engineering; Chongqing Medical University, Chongqing, China
2. Shanghai First Maternity and Infant Hospital, Shanghai, China
3. The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
4. Peking Union Medical College Hospital, Beijing, China
5. The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
6. Xinqiao Hospital Army Medical University, Chongqing, China
7. Department of Health Statistics, School of Public Health and Management, Chongqing Medical University, Chongqing, P.R. China