1. From the Departments of Radiology (P.J.v.L, J.v.d.G., J.H.) and Neurology (J.P.B., C.J.M.K.), University Medical Center Utrecht, Utrecht, The Netherlands; the Department of Radiology (P.J.v.L.), Meander Medical Center Amersfoort, Amersfoort, The Netherlands; and the Department of Radiology (J.v.d.G.), Leiden University Medical Center, Leiden, The Netherlands.