New ways of using established and emerging imaging technologies in combination could provide a new understanding of how the brain works.
European scientists have successfully combined two different ways of imaging the brain, magnetic resonance imagining (MRI), and an emerging imaging technology called magnetoencephalography (MEG) in one helmet-like device. The MEG records the magnetic fields produced by our brain, providing a real-time insight into our brain as it processes the world around it. The MRI scanning reveals structural images of the brain by looking at blood flow and oxygenation levels.
The lead scientist in the project, Professor Risto Ilmoniemi, explained how this works; “You can look at streams of information as someone is reading or looking at visual images. MRI gives the location, but not the sequence of when things happen. For MEG to pick up the electrical currents, at least a thousand neurons firing is needed. They are sending signals to each other and there are electrical currents involved, produced by neurons, and these currents can be measured.”
Scientists have previously been using MEG, and separately following up using so-called functional MRI (fMRI), which measures brain activity related to a given function by detecting associated changes in blood flow. However, the brain works much more quickly than blood oxygen levels indicate. Combining the two technologies therefore provides real benefit.
"Doing simultaneous recordings is often very valuable scientifically and clinically: measuring different types of signals at different times means you're not sure if they're measures of the same events," says Gregory Miller, Clinical Psychologist at University College California, Los Angeles. "When the machines are separate, the patient or research participant has to be removed from the equipment and the procedure repeated, which means the recordings are done under different circumstances. For example, there can be changes due to practice, boredom, or fatigue.”
Ultimately, these new advances in technology imaging could help doctors understand what is happening in the brains of particular types of patients, such as those with epilepsy. Another potential application would be in helping to guide brain surgeons away from critical areas of a patient's brain. It could help visualising areas of the brain that light up when a patient talks, for example.
The European project has now produced a prototype that combines MEG and MRI. They hope to make improvements and have it suitable for clinical use in four to five years.
