1. Department of Radiology, Affiliated Kunshan Hospital of Jiangsu University, Kunshan, Jiangsu, PR China
2. Department of Obstetrics and Gynecology, Affiliated Kunshan Hospital of Jiangsu University, Kunshan, Jiangsu, PR China
3. Department of Ultrasound Diagnosis, Affiliated Kunshan Hospital of Jiangsu University, Kunshan, Jiangsu, PR China