1. Department of Clinical Radiology, Tottori University Hospital, 36-1 Nishi-cho, Yonago, Tottori 683-8504, Japan
2. Department of Quantum Medical Technology, Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan
3. Department of Quantum Medical Technology, Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan
4. Preparing Section for New Faculty of Medical Science, Fukushima Medical University, 1 Hikariga-oka, Fukushima, Fukushima 960-1295, Japan
5. Division of Diagnostic Medical Physics, Department of Radiology, Virginia Commonwealth University Medical Center, 1300 East Marshall Street, Richmond, VI 23298-0615, USA