1. Neonatal Division, Maternal and Perinatal Center, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
2. Division of Neuropediatrics, Nagano-Children's Hospital, Azumino, Nagano, Japan
3. Department of Diagnostic Radiology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan
4. Department of Pathology, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan