1. Department of Cardiovascular Medicine Gunma University Graduate School of Medicine 3‐39‐22 Showa‐machi Maebashi 371‐8511 Japan
2. Department of Health Gunma University Graduate School of Health Science Maebashi Japan
3. Department of Cardiovascular Medicine Hokkaido University Graduate School of Medicine Sapporo Japan
4. Department of Radiology Kanazawa University Graduate School of Medical Sciences Kanazawa Japan
5. Japanese Red Cross Maebashi Hospital Maebashi Japan