[1] Vanderbilt Univ, Dept Radiol & Radiol Sci, Med Ctr, Div Neuroradiol, Nashville, TN 37232 USA
[2] Vanderbilt Univ, Monroe Carrell Jr Childrens Hosp, Med Ctr, Dept Neurol Surg,Div Pediat Neurosurg, Nashville, TN 37232 USA
[3] Vanderbilt Univ, Monroe Carrell Jr Childrens Hosp, Med Ctr, Dept Radiol & Radiol Sci,Div Neuroradiol, Nashville, TN 37232 USA