1. Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P. R. China
2. Health Management (Physical Examination) Center, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P. R. China
3. Institute of Ultrasound Imaging of Chongqing Medical University, Chongqing 400010, P. R. China
4. Department of Ultrasound, Bishan Hospital of Chongqing, Bishan Hospital of Chongqing Medical University, Chongqing 400010, P. R. China
5. Department of Ultrasound, Chongqing General Hospital, Chongqing 401147, P. R. China
6. Department of Ultrasound, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P. R. China
7. Department of Ultrasound, The Third People’s Hospital of Chengdu City, The Affiliated Hospital of Southwest Jiaotong University, Chengdu 610031, P. R. China
8. Department of Ultrasound, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, P. R. China