1. Chongqing Haifu Hospital, Chongqing, China
2. State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing, China
3. Chongqing Key Laboratory of Biomedical Engineering, Chongqing Medical University, Chongqing, China
4. Yongchuan Maternal and Child Health Care Hospital of Chongqing, Chongqing, China
5. Department of Gynaecology, Third Xiangya Hospital of Central South University, Changsha, Hunan, China
6. Department of Gynaecology, Three Gorges Central Hospital of Chongqing, Chongqing, China