1. Department of Pediatrics, Sungae Hospital, Seoul, Korea.
2. Department of Pediatrics, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea.
3. Department of Pediatrics, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
4. Department of Radiology, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea.