1. Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
2. Department of Clinical Epidemiology and Biostatistics, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
3. Deparment of Pathology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
4. Deparment of Neurosurgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea