1 Department of Medical Radiation Sciences, Faculty of Life Sciences, Kumamoto University, 2-24-1 Kuhonji, Chuo-ku, Kumamoto 862-0976, Japan.
2 Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan. Electronic address: seisei0430@nifty.com.
3 Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
4 Department of Central Radiology, Kumamoto University Hospital, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.