1. From the Departments of Radiology (M.N., E.J.I.C., M.R.P.) and Rheumatology (E.I., J.A.), Hospital Sant Joan de Déu, Passeig Sant Joan de Déu 2, 08950 Esplugues de Llobregat, Barcelona, Spain; Department of Medical Imaging, University of Toronto, Toronto, ON, Canada (M.N., O.M.N.); and Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, Canada (M.N., O.M.N.).