1. Department of Neurosurgery, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
2. Department of Neurosurgery, Hamanomachi Hospital, Fukuoka, Japan
3. Department of Clinical Radiology, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
4. Department of Neurosurgery, Sasebo Kyosai Hospital, Nagasaki, Japan