1. From the Institute for Clinical Radiology (M.P.F., K.M.T., F.G.M., B.O.S., B.E.-W., W.H.S., W.G.K.), Department of Neuroradiology (F.D.), and Department of Neurology (P.S.), Ludwig-Maximilians-University Hospital Munich, Germany; and Department for Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, University Hospital Tuebingen, Germany (A.E.O.).