1. Department of Cardiovascular Medicine and Diagnostic Radiology, Faculty of Life Sciences, Graduate School of Medical Sciences Kumamoto University 1‐1‐1, Honjo, Chuo‐ku Kumamoto 860‐8556 Japan
2. Department of Diagnostic Radiology, Faculty of Life Sciences Kumamoto University Kumamoto Japan
3. Department of Cardiovascular Medicine Shiga University of Medical Science Otsu Japan
4. Department of Bioscience and Genetics National Cerebral and Cardiovascular Center Suita Japan
5. Center for Epidemiologic Research in Asia Shiga University of Medical Science Otsu Japan