1. Department of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul 110-744, Korea.
2. Department of Radiology, Wonkwang University Hospital, Iksan 570-711, Korea.
3. Department of Radiology, Hanyang University College of Medicine, Hanyang University Hospital, Seoul 133-792, Korea.
4. Department of Radiology, Daerim Saint Mary's Hospital, Seoul 150-822, Korea.
5. Department of Radiology, Asan Medical Center, Seoul 138-736, Korea.
6. Department of Endocrinology, Seoul National University College of Medicine, Seoul 110-744, Korea.
7. Human Medical Imaging and Intervention Center, Seoul 137-902, Korea.