1. Kawasaki University of Medical Welfare Department of Radiological Technology, Faculty of Health Science and Technology, , 288 Matsushima, Kurashiki City 701-0193 Japan
2. Kumamoto University Department of Medical Physics, Faculty of Life Sciences, , Kumamoto 860-8555 , Japan
3. Graduate School of Medical Sciences, Kumamoto University Department of Diagnostic Radiology, , 1-1-1 Honjo, Kumamoto 860-8556 , Japan
4. Tsuchiya General Hospital Department of Diagnostic Radiology, , Nakajima-cho 3-30, Hiroshima 730-8655 , Japan
5. Tsuchiya General Hospital Department of Radiological Technologist, , Nakajima-cho 3-30, Hiroshima 730-8655 , Japan
6. Hiroshima University Department of Diagnostic Radiology, Graduate School of Biomedical Sciences, , Hiroshima 739-0046 , Japan