Min-Po Ho1, An-Hsun Chou2, Wing-Keung Cheung3, Kuang-Chau Tsai1. 1. Department of Emergency Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan. 2. Department of Anesthesiology, Chang Gung Memorial Hospital, College of Medicine, Chang Gung University, Taoyuan, Taiwan. 3. Division of Medical Imaging, Department of Radiology, Far Eastern Memorial Hospital, New Taipei City, Taiwan.