1. From the Department of Diagnostic and Interventional Radiology, School of Medicine & Klinikum Rechts der Isar, Technical University of Munich, Ismaningerstr 22, 81675 Munich, Germany (F.T.G., A.A.F., A.P.S., M.R.M., D.P., F.P.); Department of Physics and Munich School of BioEngineering, Technical University of Munich, Garching, Germany (T.U., M.F., K.W., W.N., P.B., R.S., F.P.); and Philips Research, Hamburg, Germany (T.K., J.v.B.).