Therefore, if a clinical study requires densitometry of the axial skeleton or diagnostic classification of osteoporotic status, standard densitometry would be required. In conclusion, this study has demonstrated that areal BMD of the UD radius can be accurately simulated from 3D HR-pQCT images of the distal radius. This approach has the potential to serve as a surrogate forearm BMD measure for clinical HR-pQCT studies. Acknowledgments The authors would like to thank Dr. Andres Laib and Scanco Medical AG for providing software learn more development support

and to acknowledge Thelma Munoz, Jingyi Yu, Nicole Cheng, Melissa Guan, and Ayako Suzuki for their contributions to clinical coordination, DXA and HR-pQCT imaging, and database management. They would also like to thank Dr. Sven Prevrhal of UCSF for helpful technical discussions. This publication was supported by NIH/NCRR UCSF-CTSI grant number UL1 RR024131-01 (AJB), NIH RO1 AG17762 (SM), and NIH F32 AR053446 (GJK). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH. Conflicts of interest None.

Open Access This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, ATR inhibitor and reproduction in any medium, provided the original author(s) and source are credited. References 1. (1991) Consensus development conference: prophylaxis and treatment of osteoporosis. Am J Med 90:107-110. 2. Beck TJ, Oreskovic TL, Stone KL, Ruff CB, Ensrud K, Nevitt

MC, Genant HK, Cummings SR (2001) Structural adaptation to changing skeletal load in the progression toward Digestive enzyme hip fragility: the study of osteoporotic Eltanexor fractures. J Bone Miner Res 16:1108–1119CrossRefPubMed 3. Stone KL, Seeley DG, Lui LY, Cauley JA, Ensrud K, Browner WS, Nevitt MC, Cummings SR (2003) BMD at multiple sites and risk of fracture of multiple types: long-term results from the Study of Osteoporotic Fractures. J Bone Miner Res 18:1947–1954CrossRefPubMed 4. Black DM, Thompson DE (1999) The effect of alendronate therapy on osteoporotic fracture in the vertebral fracture arm of the Fracture Intervention Trial. Int J Clin Pract Suppl 101:46–50PubMed 5. Delmas PD, Seeman E (2004) Changes in bone mineral density explain little of the reduction in vertebral or nonvertebral fracture risk with anti-resorptive therapy. Bone 34:599–604CrossRefPubMed 6. Hildebrand T, Laib A, Muller R, Dequeker J, Ruegsegger P (1999) Direct three-dimensional morphometric analysis of human cancellous bone: microstructural data from spine, femur, iliac crest, and calcaneus. J Bone Miner Res 14:1167–1174CrossRefPubMed 7. Muller R, Ruegsegger P (1997) Micro-tomographic imaging for the nondestructive evaluation of trabecular bone architecture. Stud Health Technol Inform 40:61–79PubMed 8.