MRI technique detects cognitive decline in healthy individuals

A new study revealed that a new technique of magnetic resonance imaging (MRI) technique can detect signs of cognitive decline in the brain even before symptoms appear, which has the potential to serve as a biomarker in very early diagnosis of preclinical dementia.

The World Health Organization estimated that dementia affects more than 35 million people worldwide, a number expected to more than double by 2030.

Researchers recently studied arterial spin labeling (ASL), a promising MRI technique that doesn't require injection of a contrast agent. ASL measures brain perfusion, or penetration of blood into the tissue.

Study author Sven Haller, M.D., from the University of Geneva in Geneva, Switzerland led an experiment that included 148 healthy elderly participants and 65 people with mild cognitive impairment (MCI). The participants underwent brain MRI and a neuropsychological assessment, a common battery of tests used to determine cognitive ability.

Of the 148 healthy individuals, 75 remained stable, while 73 deteriorated cognitively at 18 months clinical follow-up. Those who deteriorated had shown reduced perfusion at their baseline ASL MRI exams, in an area in the middle of the brain that is associated with the default mode network, the neural network. Declines in this network are seen in MCI patients and are more pronounced in those with Alzheimer's disease.

Healthy individuals who went on to develop cognitive deficits were similar to that of patients with MCI.

The results suggested that individuals with decreased perfusion detected with ASL MRI may temporarily maintain their cognitive status through the mobilization of their cognitive reserve, but will eventually develop subtle cognitive deficits.

It was found that ASL MRI has potential as a standalone test or as an adjunct to PET that subjects patients to radiation and it does not expose the patient to radiation and is easy to perform in routine clinical settings.

The study published online in the journal Radiology.