[1] Indiana Univ, Riley Hosp Children, Dept Radiol, Indianapolis, IN 46204 USA
[2] Cincinnati Childrens Hosp Med Ctr, Perinatal Inst, Cincinnati, OH 45229 USA
[3] Cincinnati Childrens Hosp Med Ctr, Div Neonatol, Div Biostat & Epidemiol, Cincinnati, OH 45229 USA
[4] Cincinnati Childrens Hosp Med Ctr, Fetal Care Ctr, Cincinnati, OH 45229 USA
[5] Cincinnati Childrens Hosp Med Ctr, Dept Radiol, Cincinnati, OH 45229 USA
[6] Univ Cincinnati, Dept Math, Cincinnati, OH USA