1. Department of Radiology; University of Ulsan College of Medicine, Asan Medical Center; Seoul Korea
2. Department of Radiology, Gyeongsang National University School of Medicine; Gyeongsang National University Changwon Hospital; Changwon Korea
3. Preventive Medicine; University of Ulsan College of Medicine; Asan Medical Center Seoul Korea
4. Department of Radiology, Soonchunhyang University College of Medicine; Soonchunhyang University Bucheon Hospital; Bucheon Korea
5. Department of Radiology, Chung-Ang University College of Medicine; Chung-Ang University Medical Center; Seoul Korea