1. From the Department of Radiology, Charité-Universitätsmedizin Berlin, Humboldt-Universität and Freie Universität zu Berlin, Schumannstr 20/21, Berlin 10117, Germany (E.S., M.B., E.Z., R.T, M.L., M.D.); and Institute for Clinical Epidemiology and Applied Biometry, University of Tübingen, Tübingen, Germany (P.M.).