1. Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
2. Department of Pediatrics, School of Medicine, Kyungpook National University, Daegu, Korea.
3. Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
4. Department of Radiology and Center for Imaging Science, Sungkyunkwan University School of Medicine, Korea.