Alzheimer's disease, one kind of dementia, is a complex progressive neurodegenerative disorder characterized by extracellular amyloid β and intraneuronal tau protein aggregations of the brain and is usually detected using diffusion tensor imaging (DTI) MRI, which is a sensitive measure of white matter damage that may predict future dementia risk in cerebral small vessel disease and in mild cognitive impairment. This evidence concerns the gene MAPT and dementia.