PET/SPECT for dementia—early diagnosis of Alzheimer's disease

Patients with mild cognitive impairment (MCI) convert to Alzheimer's disease (AD) at approximately 12% per year (Petersen et al.). The prediction of conversion from MCI to AD by early markers of AD is taken into consideration. PET/SPECT is expected as a most promising marker. Therefore the presentation of scientific evidence based on a high-level clinical trial is pressing need. In Japan, Japan Cooperative SPECT Study on Assessment of Mild Impairment of Cognitive Function (J-COSMIC) was started as an assignment study of the Japan Foundation for Aging and Health in 2003. This research is aimed at clarifying the role of brain perfusion SPECT in early diagnosis of AD in the MCI stage. Currently 41 institutions participate in this study, and more than 300 MCI cases have been registered. In order to confirm the conversion from MCI to AD, the follow-up survey for 3 years after the first time evaluation will be performed, and then the diagnostic ability of the SPECT will be calculated. Furthermore a multicenter study on early diagnosis of AD with FDG-PET in Japan (SEAD-Japan) is also due to be started from this year to establish the scientific evidence of early diagnosis of AD with FDG-PET.