1. Department of Internal Medicine, Kangwon National University Hospital, Chuncheon, Korea
2. Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, Korea
3. Department of Radiology, Kangwon National University School of Medicine, Chuncheon, Korea
4. Department of Thoracic and Cardiovascular Surgery, Kangwon National University School of Medicine, Chuncheon, Korea