Intra-operative "real-time" navigation system updated with open MRI - Kosaku Amano; Yoshihiro Muragaki; Hiroshi Iseki; Takashi Maruyama; Madoka Sugiura; Masayuki Yamato; Ryuuiti Matida; Tomokatsu Hori; Kintomo Takakura (CARS 2001. Computer Assisted Radiology and Surgery. Proceedings of the 15th International Congress and Exhibition, Berlin, Germany, June 27-30, 2001, 2001)