1. Graduate School of Health Sciences Tokushima University Tokushima770‐8503Japan
2. Department of Therapeutic Radiology Institute of Biomedical Sciences Tokushima University Graduate School Tokushima770‐8503Japan
3. Department of Radiology and Radiation Oncology Institute of Biomedical Sciences Tokushima University Graduate School Tokushima770‐8503Japan
4. Department of Oral and Maxillofacial Surgery Institute of Biomedical Sciences Tokushima University Graduate School Tokushima770‐8503Japan
5. Department of Radiological Technology Kochi Medical School Hospital Nankoku‐shi Kochi783‐8505Japan