Researchers at Aalto Uni versity in Finland have de veloped the world’s first device designed to map the human brain that combines whole-head magnetoencephalo graphy (MEG) and magnetic resonance imaging (MRI) technology.
Modern MEG systems use arrays comprising hundreds of superconducting quantum interference device channels to measure the magnetic field generated by neuronal activity. While MEG measures the electrical function, the MRI simultaneously visualizes the brain’s structure. By merging these two technologies, the researchers say, the hybrid MEG-MRI instrumentation device will produce unprecedented accuracy in locating brain electrical activity non-invasively.
In addition to studying brain function, MEG can be used to diagnose epilepsy, stroke, and some mental illnesses. In about 20 percent of epilepsy patients, drugs don’t adequately control seizures, so for those patients, surgical removal of brain tissue where the seizures originate is the best option.
Precisely pinpointing that tissue and avoiding nearby tissue needed for motor control, sense perception, language, and memory is essential. While seizures occur sporadically, the electrical activity associated with them occurs continually. By locating the electrical activity that precedes a seizure, the problematic tissue can be isolated for removal.
One major advantage of MEG over traditional electroencephalography (EEG) is that an EEG requires gluing up to 150 electrodes to the patient’s scalp. MEG measures brain currents as precisely as an EEG but without physical contact, allowing technicians to screen large numbers of patients quickly and easily.
When MEG is used separately, image accuracy can be compromised because of the brain’s movement and the image it provides may not be accurate enough for precise brain surgery. Previously, it was not possible to combine high-field MRI and MEG because their magnetic fields interfered with one another. But now, extremely sensitive magnetic field sensors have now been developed. Since no high-field MRI is necessary, there are numerous safety benefits for patients with pacemakers and metal implants, pregnant women, and infants.
To see the device in action, go to: http://www.techbriefs.com/tv/brainactivity