1. Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
2. Department of Neurosurgery, Seoul St' Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
3. Department of Neurosurgery, Bucheon St. Mary's Hospital, The Catholic University of Korea, Gyeonggi-do, Korea.
4. Department of Radiology, Asan Medical Center, University of Ulsan, Seoul, Korea.
5. Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
6. Department of Radiology, Pusan National University Yangsan Hospital, Pusan National University, Yangsan, Korea.
7. Department of Radiology, Pusan National University Hospital, Pusan National University, Busan, Korea.
8. Department of Neurosurgery, Kyungpook National University Hospital, Kyungpook National University, Daegu, Korea.
9. Department of Radiology, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
10. Department of Radiology, Chung-Ang University Hospital, Seoul, Korea.
11. Department of Neurosurgery, Dong-Eui Medical Center, Busan, Korea.
12. Department of Neurosurgery, Sejong General Hospital, Gyeonggi-do, Korea.
13. Department of Neurosurgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
14. Department of Radiology, Seoul St' Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
15. Department of Neurosurgery, Asan Medical Center, University of Ulsan, Seoul, Korea.
16. Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
17. Department of Neurosurgery, Pusan National University Yangsan Hospital, Pusan National University, Yangsan, Korea.