1. From the Department of Neuroradiology (B.S.G., J.F., C.S., H.Z., T.K.), University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of Neurology (F.B.), Universitätsklinikum Münster, Germany; Department of Diagnostic Radiology (O.S.), MR Center, University Hospital Center Freiburg, Germany; Department of Neurology (J.R.), Klinikum Minden, Germany.