1. Advanced Biomedical Imaging Research Center; Kobe University Graduate School of Medicine; Kobe Hyogo Japan
2. Division of Functional and Diagnostic Imaging Research, Department of Radiology; Kobe University Graduate School of Medicine; Kobe Hyogo Japan
3. Division of Radiology, Department of Radiology; Kobe University Graduate School of Medicine; Kobe Hyogo Japan
4. Department of Radiology; Hyogo Cancer Center; Akashi Hyogo Japan
5. Toshiba Medical Systems Corporation; Otawara Tochigi Japan
6. Toshiba Medical Research Institute USA; Vernon Hills Illinois USA