Imaging provides unique, direct information about the structural aging of the brain, which cannot be obtained from blood tests or other molecular biomarkers. For example, key indicators of aging include the thickness of the cerebral cortex, which controls speech and thinking, and the volume of gray matter. By assessing these and other characteristics, scientists decided to create a tool for detecting the rate of brain aging using MRI. The results were published in Nature.
To train the algorithm, scientists used data from more than a thousand New Zealanders born between 1972 and 1973. The AI looked for correlations between brain scan results and important health indicators, including cardiovascular, metabolic, and immune function, among others.
The result was a new "aging clock," which proved informative when validated across a sample of nearly 45,000 scans. For example, accelerated brain aging at age 72 was associated with the highest risk of developing dementia over the next 16 years.
While the authors are still refining the algorithm, they see great potential for this new AI for clinical use. In the future, a simple brain MRI could become an important screening tool for the elderly and those at high risk for dementia.
Previously, other scientists successfully used MRI to assess the risk of developing heart failure. For example, a change in one indicator increased the risk of the disease fivefold.
