[1] ASPETAR Qatar Orthopaed & Sports Med Hosp, Doha, Qatar
[2] Boston Univ, Sch Med, Dept Radiol, Boston, MA 02118 USA
[3] Yale Univ, Sch Med, Dept Radiol, Bridgeport Hosp, Bridgeport, CT 06610 USA
[4] Boston Univ, Sch Med, Clin Epidemiol Res & Training Unit, Boston, MA 02118 USA
[5] Univ Erlangen Nurnberg, Dept Radiol, D-91054 Erlangen, Germany