[1] NIAMSD, Rheumatol, NIH, Bethesda, MD 20892 USA
[2] NIH, Radiol & Imaging Sci, Bldg 10, Bethesda, MD 20892 USA
[3] NIAMSD, NIH, Bethesda, MD 20892 USA
[4] Univ Penn, Perelman Sch Med, Philadelphia, PA 19104 USA
[5] Georgetown Univ, Rheumatol, Bethesda, MD USA