1. Department of Radiology West China Second University Hospital, Sichuan University Chengdu China
2. Department of Ultrasonography Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology Chengdu China
3. Department of Ultrasonography West China Second University Hospital, Sichuan University Chengdu China
4. Department of Radiology Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology Chengdu China