1. Division of Pulmonary and Critical Care Medicine; Department of Internal Medicine; Seoul National University College of Medicine; Seoul National University Hospital; Seoul Korea
2. Division of Pulmonary and Critical Care Medicine; Department of Internal Medicine; Seoul National University College of Medicine; Seoul Metropolitan Government-Seoul National University Boramae Medical Center; Seoul Korea
3. Department of Radiology; Seoul National University College of Medicine; Seoul National University Hospital; Seoul Korea
4. Department of Thoracic and Cardiovascular Surgery; Seoul National University College of Medicine; Seoul National University Hospital; Seoul Korea