1. Department of Radiology, Wonju Christian Hospital, Yonsei University Wonju College of Medicine, Gangwon-do 220-701, Korea.
2. Department of Neurology, Wonju Christian Hospital, Yonsei University Wonju College of Medicine, Gangwon-do 220-701, Korea.
3. Department of Neurosurgery, Wonju Christian Hospital, Yonsei University Wonju College of Medicine, Gangwon-do 220-701, Korea.