Alternatives require the use of radioactive chemicals and a PET (positron emission tomography) scanner, which is expensive.

The blood flow measures can be correlated with other tasks (such as eye movements) that arise from the study.

So far, researchers have found some areas of the brain, such as the parietal lobe, have reduced blood flow because of Alzheimer's, a finding that corresponds with some of the well-known effects of the disease.

'This new approach to safely measure brain blood flow through MRI may enable physicians and scientists to distinguish between different kinds of dementia,' said Michael MacAskill, chief scientist at the Van der Veer Institute.