1 Department of General Pediatrics and Interdisciplinary Medicine, National Center for Child Health and Development, Tokyo, 157-8535, Japan. iijima-hi@ncchd.go.jp.
2 Division of Pediatric Emergency and Transport Services, National Center for Child Health and Development, Tokyo, Japan.
3 Division of Diagnostic Imaging, Department of Radiology, National Center for Child Health and Development, Tokyo, Japan.
4 Division of Infectious Diseases, Department of Medical Subspecialties, National Center for Child Health and Development, Tokyo, Japan.