1. Department of Internal Medicine, Biomedical Research Institute Pusan National University Hospital Busan Korea
2. Department of Clinical Epidemiology and Biostatistics, Asan Medical Center University of Ulsan College of Medicine Seoul Korea
3. Department of Internal Medicine, Asan Medical Center University of Ulsan College of Medicine Seoul Korea
4. Department of Nuclear Medicine, Asan Medical Center University of Ulsan College of Medicine Seoul Korea