[1] Univ Zurich Hosp, Clin Angiol, CH-8091 Zurich, Switzerland
[2] Univ Zurich Hosp, Inst Diagnost & Intervent Radiol, CH-8091 Zurich, Switzerland
[3] Boston Childrens Hosp, Div Intervent Radiol, Boston, MA USA
[4] Harvard Univ, Sch Med, Cambridge, MA 02138 USA