1. Department of Bioengineering, University of California, San Diego, CA, USA
2. Department of Orthopaedic Surgery, University of California, San Diego, CA, USA
3. Research Service, VA San Diego Healthcare System, San Diego, CA, USA
4. Department of Radiology, Santa Barbara Cottage Hospital, Santa Barbara, CA, USA
5. Department of Radiology, University of California, San Diego, CA, USA
6. Radiology, Fifth Affiliated Hospital of Sun Yat-sen University, Zhu Hai, China
7. Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
8. Radiology Service, VA San Diego Healthcare System, San Diego, CA, USA