[1] Johns Hopkins Univ, Sch Med, Russell H Morgan Dept Radiol & Radiol Sci, Sect Pediat Neuroradiol,Div Pediat Radiol, Baltimore, MD 21218 USA
[2] Johns Hopkins Univ, Sch Med, Dept Neurol, Baltimore, MD 21218 USA
[3] Johns Hopkins Univ, Sch Med, Neurosci Intens Care Nursery, Baltimore, MD 21218 USA