Affiliation: | (1) Department of Anesthesiology and Pain Medicine, Asan Medical Center, Ulsan University College of Medicine, Seoul, Korea;(2) Department of Radiology, Soonchunhyang University College of Medicine, Bucheon, Korea;(3) Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, 120-752 Seoul, Korea;(4) Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea; |