1. Department of Obstetrics and Gynaecology, People’s Hospital of Deyang City, Deyang, China
2. Department of Cerebrovascular Disease, Suining Central Hospital, Suining, China
3. State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing, China
4. Chongqing Key Laboratory of Biomedical Engineering, Chongqing Medical University, Chongqing, China