1. From the Departments of Diagnostic Imaging (E.J.I.C., M.N.I., E.L., C.C., P.S., I.B.M.d.l.T.) and Pathology (M.S.), Hospital Sant Joan de Déu, Av Sant Joan de Déu 2, 08950 Esplugues de Llobregat (Barcelona), Spain; and Departments of Medical Imaging, University of Toronto, and Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada (O.M.N.).