[1] Univ Childrens Hosp Zurich, Dept Pediat Neurol, Zurich, Switzerland
[2] Univ Childrens Hosp Zurich, Div Diagnost Imaging, Zurich, Switzerland
[3] Johns Hopkins Univ, Sect Pediat Neuroradiol, Russell H Morgan Dept Radiol & Radiol Sci, Div Pediat Radiol,Sch Med, Baltimore, MD USA
[4] Univ Childrens Hosp, Dept Pediat Neurol, CH-8032 Zurich, Switzerland