Portable MRI for diagnosing stroke

The Jane and Aatos Erkko Foundation awarded nearly a million euros to research headed by mathematics professor Samuli Siltanen.

Stroke is a serious national health problem. It causes 9% of deaths in Finland, and it leaves every fourth survivor with brain damage.

- If the right treatment can be started quickly, preferrably in the ambulance, it is possible to make a complete recovery, says Samuli Siltanen, professor of industrial mathematics at the University of Helsinki.

Strokes are caused by lack of oxygen due to a blood clot, or a bleed in the brain. The external symptoms of these two alternatives are the same, but they require completely opposite treatments;  a bleeding patient must not be treated with a blood-thinner, for example, like a blood clot would.

Thus, it is vital to be able to see immediately after the symptoms appear, which alternative it is.

Affordable equipment in each ambulance

The choice of correct treatment is difficult, and it currently requires the kind of large magnetic or tomographic imaging device found in hospitals.

The goal of Samuli Siltanen’s research project is to develop a new, affordable and mobile imaging device. The imaging will be based on feeding harmless electric currents into the brain via electrodes that are attached to the patient’s head.

- The lack of blood in certain areas of the brain leads to low conductivity, while bleeding causes high conductivity. This is why electric imaging is a promising approach to this problem, says Siltanen.

- Interpreting the measurements is, however, a very challenging mathematical task, he says.

The other members of Professor Samuli Siltanen’s research consortium are Professor Jari Hyttinen, expert in bioimpedance and phsyiological modelling from Tampere University of Technology, and Professor Ville Kolehmainen, expert in medical imaging from the University of Eastern Finland.

It is a three-year project, and the Jane and Aatos Erkko Foundation is backing the research into electrical imaging of strokes with 950,000 euros.

Picture: Computer simulation of the planned imaging method. Left: simulated head with brain. The red area is a roughly modelled brain bleed. Centre and right: reconstructions of electric imaging with the new method, so this is not a photo of a patient. Photo:  Samuli Siltanen, University of Helsinki