[18F]Fluorodeoxyglucose Positron Emission Tomography in Alzheimer Disease and Related Disorders

The numbers of cases of Alzheimer disease (AD) and related disorders have been increasing with higher life expectancy worldwide. In particular, the incidence has sharply increased in people aged 70 to 80 years, with consequent significant burdens on health care systems and economies. In the 1990s, more than 4% of individuals aged over 65 years were affected by AD (Folstein et al., 1991), and 7–10% of this age group in Japan have been estimated to have AD (Meguro et al., 2002). Worldwide, the estimated number of individuals with AD of 24.3 million in 2001 is expected to increase to 42.3 million by 2020, and to 81.1 million by 2040 (Ferri et al., 2005).