[1] Kyushu Natl Canc Ctr, Dept Cerebrovasc Dis, Chuo Ku, Fukuoka 8108563, Japan
[2] Kyushu Natl Canc Ctr, Neuroradiol Cerebrovasc Ctr, Fukuoka 8108563, Japan
[3] Kyushu Natl Canc Ctr, Clin Res Ctr, Fukuoka 8108563, Japan
[4] Kyushu Univ, Grad Sch Med Sci, Dept Med & Clin Sci, Fukuoka 812, Japan