1. Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan
2. Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Japan
3. Canon Medical Systems Corporation, Otawara, Japan
4. Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan
5. Department of Radiology, Osaka Police Hospital, Osaka, Japan