作者单位:Washington Univ, Dept Pediat, Div Neurol, St Louis, MO 63130 USA[1]Brigham & Womens Hosp, Dept Pediat Newborn Med, 75 Francis St, Boston, MA 02115 USA[2]Washington Univ, Dept Pediat, St Louis, MO 63130 USA[3]Washington Univ, Sch Med, Mallinckrodt Inst Radiol, Div Diagnost Radiol, St Louis, MO USA[4]Washington Univ, Sch Med, Dept Obstet & Gynecol, St Louis, MO 63110 USA[5]