1. Clinical Research Support Center, Inje University Ilsan Paik Hospital, Goyang 10380, Republic of Korea
2. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Inje University Ilsan Paik Hospital, Inje University College of Medicine, Goyang 10380, Republic of Korea
3. Department of Neurosurgery, College of Medicine, Inje University Ilsan Paik Hospital, Goyang 10380, Republic of Korea