As aging population is rapidly increasing, it is estimated that prevalence of dementia among older adults would be doubled every twenty years and number of patients would increase by one million until 2027.  Dementia would lead to a burden of care on family members, care-givers, and even societies due to social and economic cost. In addition, early diagnosis of the disease is essential to improve quality of life of patients and their family, and to reduce cost of patient care and treatment for disease.

Therefore, early diagnosis of dementia is important step to prevent further worsening of disease and improve quality of life of dementia patients and their family. In this study, we assessed diagnostic accuracy of FDG PET in evaluation of dementia, which known as a tool for detecting reduced glucose metabolism in patient’s brain even before the development of dementia symptoms.