[1] Univ Minnesota, Pk Nicollet Osteoporosis Ctr, Div Hlth Policy & Management, Pk Nicollet Hlth Serv, Minneapolis, MN 55416 USA
[2] Univ Calif San Francisco, Dept Radiol & Biomed Imaging, San Francisco, CA 94143 USA
[3] Columbia Univ, Coll Phys & Surg, Dept Med, New York, NY USA
[4] Univ Miami, Miller Sch Med, Miami, FL 33136 USA