[1] Childrens Hosp Philadelphia, Pediat Rheumatol, Philadelphia, PA 19104 USA
[2] Univ Penn, Dept Biostat & Epidemiol, Perelman Sch Med, Philadelphia, PA 19104 USA
[3] Childrens Hosp Philadelphia, Rheumatol, Philadelphia, PA 19104 USA
[4] Childrens Hosp Philadelphia, Radiol, Philadelphia, PA 19104 USA
[5] Penn State Hershey Med Ctr, Radiol, Hershey, PA USA
[6] Childrens Hosp Philadelphia, Pediat, Philadelphia, PA 19104 USA