1. Department of Neurosurgery, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation and Tzu Chi University, Hualien, Taiwan
2. Department of Radiology, Taipei Veterans General Hospital and School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
3. Department of Radiology, Tri-Service General Hospital and National Defenses Medical Center, Taipei, Taiwan