1. Department of Ultrasound, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, P. R. China
2. State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China
3. Department of Ultrasound, The Affiliated People’s Hospital of Jiangsu University, Zhenjiang 212002, P. R. China
4. Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, P. R. China