1. Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
2. Department of Diagnostic Radiology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
3. Institute of Gerontology, The University of Tokyo, Tokyo, Japan
4. Institute for Future Initiatives, The University of Tokyo, Tokyo, Japan
5. Department of Nuclear Medicine, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Kiyose, Japan
6. Center for Dementia, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Kiyose, Japan