Novel MRI technique could offer new avenue for Alzheimer’s, stroke risk assessment

A new MRI scanning technique being investigated in Toronto could one day help physicians identify patients on the path to developing Alzheimer’s disease, and do so at a cost far less than molecular imaging of amyloid deposits, according to an in-depth profile of the project published by the Toronto Star.

The technique involves the field of cerebrovascular reactivity (CVR) measurement and the use of an MRI scan to watch the brain’s response to elevated levels of carbon dioxide.

As explained in the Star profile, patients are fitted with an oxygen mask that gradually raises the concentration of CO₂ in the blood to more than 20 percent higher than that produced by normal respiration.

In a healthy brain, blood vessels should widen to increase the flow of oxygen as a response to higher CO₂ levels. The thinking behind the current study is that patients in the early stages of Alzheimer’s or other neurological conditions will have vessels that don’t properly expand.

Mapping these vessels could be the key, as MRI comparisons between groups of patients with mild cognitive impairment and patients will full-blown Alzheimer’s could help spot those at risk from transitioning from the former group to the latter.

Importantly, in this cost-conscious era, the MRI test of CO₂ response would likely cost one-sixth the price of current amyloid imaging techniques.

The researchers—including David Mikulis, MD, and Joe Fisher, MD, of Toronto Western Hospital—note that beyond Alzheimer’s, the technique could have application for a host of other brain disorders. CVR status has already been revealed to be an important indicator of stroke risk, according to the Toronto Star.

Work is in the early stages, but Mikulis and Fisher hope one day the technique earns regulatory approval in Canada and the U.S.

For more on this promising new technique, click here for the full profile of the Toronto Western research.