1. PET-CT Dementia Research Center; Juntendo Tokyo Koto Geriatric Medical Center; Juntendo University School of Medicine; Tokyo Japan
2. Department of Psychiatry; Yokohama City University School of Medicine; Yokohama Japan
3. Department of Psychiatry; Yokohama Hoyu Hospital; Yokohama Japan
4. Department of Psychiatry; Juntendo University School of Medicine; Tokyo Japan
5. Graduate School of Comprehensive Human Sciences; University of Tsukuba; Ibaraki Japan