1. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
2. Department of Internal Medicine, National Health Insurance Service Ilsan Hospital, Goyang, Korea.
3. Department of Radiology, National Health Insurance Service Ilsan Hospital, Goyang, Korea.
4. Department of Pathology, National Health Insurance Service Ilsan Hospital, Goyang, Korea.
5. Department of Thoracic and Cardiovascular Surgery, National Health Insurance Service Ilsan Hospital, Goyang, Korea.