[1] Brown Univ, Warren Alpert Med Sch, Providence, RI 02912 USA
[2] Tufts Med Ctr, Boston, MA USA
[3] Brigham & Womens Hosptial, Dept Radiol, Boston, MA USA
[4] Harvard Med Sch, Boston, MA USA
[5] Mem Hosp Rhode Isl, Pawtucket, RI USA
[6] Diakonhjemmet Hosp, Dept Rheumatol, Oslo, Norway
[7] Tufts Med Ctr, Div Rheumatol, Boston, MA USA
[8] Brigham & Womens Hosp, Div Rheumatol Immunol & Allergy, 75 Francis St, Boston, MA 02115 USA