1. State Key Laboratory of High Performance Ceramic and Superfine Microstructures; Shanghai Institute of Ceramics; Chinese Academy of Science; Shanghai 200050 P.R. China
2. College of Biomedical Engineering; Chongqing Medical University; Chongqing 400010 P. R. China
3. Department of Medical Ultrasound; Tenth People's Hospital of Tongji University; Shanghai 200072 P. R. China
4. Department of Ultrasound in Medicine; Jiao Tong University Affiliated Sixth People's Hospital; Shanghai 200233 P. R. China