1. From the Service de Neuroradiologie Diagnostique et Thérapeutique (P.L.L., G.R., H.A., A.O., S.H., W.Z., S.G., D.D., T.K.), Hôpital de Bicetre, Le Kremlin-Bicetre, Paris, France; the Service Neuropediatrie (P.L.), Hôpital de Bicetre, Le Kremlin-Bicetre, Paris, France; the Department of Clinical Neuroscience (S.H.), Section for Neuroradiology, Karolinska Institute, Stockholm, Sweden; and the Department of Neuroradiology (T.K.), University Hospital of the Technical University, Aachen, Germany.