作者单位:Massachusetts Gen Hosp, Dept Radiol, Boston, MA 02114 USA[1]Massachusetts Gen Hosp, Dept Pediat, Boston, MA 02114 USA[2]Massachusetts Gen Hosp, Dept Pediat Surg, Boston, MA 02114 USA[3]Massachusetts Gen Hosp, Dept Pathol, Boston, MA 02114 USA[4]