[1] Kyushu Univ, Grad Sch Med Sci, Dept Neurosurg, Higashi Ku, Fukuoka 8128582, Japan
[2] Hamanoumachi Hosp, Dept Neurosurg, Fukuoka, Japan
[3] Kyushu Univ, Grad Sch Med Sci, Dept Clin Radiol, Fukuoka 8128582, Japan
[4] Sasebo Kyosai Hosp, Dept Neurosurg, Nagasaki, Japan