1. Department of Ultrasound, The First Hospital of Hebei Medical University, Shijiazhuang, Hebei 050030, P.R. China
2. Department of Abdominal Ultrasound, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China
3. Department of Obstetrics and Gynecology Ultrasound, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China
4. Department of Epidemiology and Statistics, School of Public Health, Hebei Medical University, Hebei Province Key Laboratory of Environment and Human Health, Shijiazhuang, Hebei 050017, P.R. China
5. Department of Immunology, Hebei Medical University, Key Laboratory of Immune Mechanism and Intervention for Serious Diseases in Hebei Province, Shijiazhuang, Hebei 050017, P.R. China
6. Department of Ultrasound, Xinqiao Hospital, Army Medical University, Chongqing 400037, P.R. China
7. Department of Cardiac Ultrasound, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China