Alternative FDG-PET relative standardized uptake value metrics for the assessment of early metabolic biomarkers of Alzheimer's disease

Alzheimer's disease (AD) is a degenerative brain disorder causing dementia. Treatments to slow or reverse AD are unrealized as are the means for early definitive disease diagnosis. The brain relies on glucose metabolism for many functions and, with radioactive glucose injections and appropriate scanning, changes in brain glucose uptake patterns can signal abnormalities in brain cell function associated with AD. However, detecting abnormal glucose uptake patterns at early stages of AD, prior to development of major brain cell loss and cognitive symptoms, has been difficult. In our imaging studies of an AD mouse model we have observed early, abnormal glucose utilization patterns when we compare glucose metabolism between different regions of the same brain. Traditionally, comparisons are made to only one region, called the cerebellum. Using our new method, the patterns of metabolism in an AD mouse model in the early stages of AD development differ from age-matched normal mice in brain regions responsible for memory and behavior. In this study, we will determine whether these same measurements can be applied for the early diagnosis of AD in humans. To test our novel approach, we will use the extensive clinical and neuroimaging database of the Alzheimer's Disease Neuroimaging Initiative (ADNI). It is anticipated that differences in relative glucose metabolism patterns also exists in people with early memory changes that later develop AD. The results may provide an early diagnostic test for AD. Early detection of AD with a brain scan will greatly enhance our ability to diagnose AD at a time when treatments can be most effective.