1. Department of Radiology, Pusan National University Yang-san Hospital, Yang-san, Korea
2. Department of Neurosurgery, Pusan National University Yang-san Hospital, Pusan National University School of Medicine, Yang-san, Korea
3. Department of Radiology, Pusan National University Hospital, Busan, Korea
4. Department of Physics, Changwon National University, Changwon, Korea