[1] Stanford Univ, Sch Med, Lucile Packard Childrens Hosp, Dept Radiol,Paediat Radiol, Stanford, CA 94305 USA
[2] Johannes Gutenberg Univ Mainz, Univ Med Ctr, Dept Diagnost & Intervent Radiol, Langenbeckst 1, D-55131 Mainz, Germany
[3] Stanford Univ, Sch Med, Dept Radiol, 300 Pasteur Dr, Stanford, CA 94305 USA
[4] Stanford Univ, Sch Med, Lucile Packard Childrens Hosp, Dept Paediat,Paediat Haematol Oncol, 1201 Welch Rd, Stanford, CA 94305 USA
[5] Stanford Univ, Sch Med, Stanford Canc Inst, 265 Campus Dr, Stanford, CA 94305 USA