Toshihiko Asanuma1, Kasumi Masuda2, Shintaro Beppu2, Satoshi Nakatani2. 1. Department of Health Sciences, Division of Functional Diagnostics, Osaka University Graduate School of Medicine, 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan. toshi@sahs.med.osaka-u.ac.jp. 2. Department of Health Sciences, Division of Functional Diagnostics, Osaka University Graduate School of Medicine, 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan.