# Brain age (MRI-based)

MRI-based brain age estimates how old your brain looks biologically, from brain-imaging features. Those features include cortical thickness, white-matter integrity, gray-matter volume, and functional connectivity. A machine-learning model, trained on large brain-scan datasets, turns them into an age. The key number is the gap between your predicted brain age and your real age, called the brain-age gap (or BrainAGE, introduced by Franke et al., 2010). A positive gap (brain looks older) goes with cognitive decline, neurodegeneration, stroke, and higher death risk. A negative gap (brain looks younger) goes with better cognitive reserve. But accuracy and interpretation vary with the imaging protocol, the processing pipeline, and who was in the training data.

## Sources

- Franke K, Ziegler G, Klöppel S, Gaser C. (2010). Estimating the age of healthy subjects from T1-weighted MRI scans using kernel methods: exploring the influence of various parameters. NeuroImage. https://doi.org/10.1016/j.neuroimage.2010.01.005

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_Canonical: https://longevity-switzerland.com/en/glossary/brain-age-mri · Part of Longevity Cities · Updated 2026-06-22_