1. Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA.
2. Department of Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA.
3. John Cochran Veterans Hospital, St. Louis, MO 63106, USA.
4. Musculoskeletal Research Center, Division of Bone and Mineral Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
5. Department of Pathology, Washington University School of Medicine, St. Louis, MO 63110, USA.