1 Department of Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka Suita, Osaka, Japan. ushuika@yahoo.co.jp.
2 Department of Diagnostic Radiology, Faculty of Medicine, Osaka Medical and Pharmaceutical University, 2-7 Daigaku-machi Takatsuki, Osaka, Japan.
3 Department of Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka Suita, Osaka, Japan.