1. Department of Internal Medicine; Seoul National University College of Medicine; Seoul Korea
2. Department of Internal Medicine; National Medical Center; Seoul Korea
3. Department of Internal Medicine; Chung-Ang University Hospital; Seoul Korea
4. Department of Internal Medicine; Dankook University Hospital; Cheonan-si Korea
5. Department of Nuclear Medicine; Seoul National University College of Medicine; Seoul Korea
6. Department of Internal Medicine; Seoul National University Boramae Medical Center; Seoul Korea
7. Department of Laboratory Medicine; Seoul National University College of Medicine; Seoul Korea