1. Department of Neurology, Kyungpook National University Hospital, Daegu, Korea.
2. School of Medicine, Kyungpook National University, Daegu, Korea.
3. Department of Radiology, Kyungpook National University Hospital, Daegu, Korea.
4. Cerebrovascular Center, Kyungpook National University Hospital, Daegu, Korea.
5. Department of Neurosurgery, Kyungpook National University Hospital, Daegu, Korea.