According to researchers in California, a brain scan may possibly identify structural and metabolic brain changes that predict dementia or cognitive decline in normal older adults.
Where these anatomical changes are located could also point to the development Alzheimer's disease.
Dr. William Jagust of the University of California, Berkeley and colleagues wanted to find out if brain imaging could identify predictors of dementia in people with normal mental function.
The researchers tracked 60 Latino community-dwelling individuals who were 60 to 100 years old for an average of 4 years.
The subjects underwent examination with two imaging techniques, positron emission tomography or PET imaging and magnetic resonance imaging or MRI.
At the follow-up, six subjects developed cognitive impairment or dementia.
According to Dr. Jagust there was a "high positive correlation" between faster declines in cognitive function on a standard test and lower glucose metabolism in key areas of the brain.
The researchers say the pattern of glucose metabolism, together with the location of brain regions that are predictive of Alzheimer's "suggests that these findings are due to the detection of presymptomatic Alzheimer's disease.
The research is published in the April edition of the Annals of Neurology.