1. From the Department of Radiology, Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, PO Box 30.001, 9700 RB, Groningen, the Netherlands (T.C.K.); and Department of Radiology, Zuyderland Medical Center, Heerlen/Sittard-Geleen, the Netherlands (R.M.K.).