Today positron emission tomography (PET) imaging is commonly used to differentiate various forms of dementia. The limitation of PET scans is that it only looks at the surface of the brain, which reduces the accuracy in determining the type of dementia the patient has developed.

Lisa Mosconi, PhD, assistant professor of psychiatry, New York University School of Medicine, felt that the type of dementia could be determined by looking beneath the surface of the brain and directly into the different areas of the brain affected by the various forms of dementia. By using a PET scanner with the radiotracer fluorodeoxyglucose (FDG) researchers were able to correctly classify the type of dementia more than 94% of the time.

Different forms of dementia were examined: Alzheimer’s disease (AD), frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB). Mosconi found that each form of dementia affects the brain in different ways. For example, Alzheimer’s patients have noticeable reduction of activity in the hippocampus; unlike FTD patients who have only a mild reduction in activity in the hippocampus and the DLB patient who has no change in activity in that area of the brain.

Mosconi’s study is also the first to use FDG PET to compare an early stage of dementia known as mild cognitive impairment (MCI) with dementing diseases other than Alzheimer’s disease. This aspect of the study is significant when considering the expected dramatic increase of dementia cases as aging baby-boomers become senior citizens. By the 2050 the number of Alzheimer’s cases is expected to triple.