[1] Hosp Sick Children, Dept Diagnost Imaging, 555 Univ Ave, Toronto, ON M5G 1X8, Canada
[2] Univ Toronto, Dept Med Imaging, Toronto, ON, Canada
[3] Great Ormond St Hosp Children NHS Fdn Trust, Dept Neuroradiol, Great Ormond St, London WC1N3JH, England
[4] Alfaisal Univ, Coll Med, Al Zahrawi St interconnecting, Riyadh 11533, Saudi Arabia
[5] UCL GOS Inst Child Hlth, London, England
[6] Great Ormond St Hosp Children NHS Fdn Trust, Dept Neuroradiol, Great Ormond St, London WC1N3JH, England