Combining MEG and MRI maps brain electrical activity with high
15 August 2012
Researchers at Aalto University in Finland have developed the
world’s first device designed for mapping the human brain that
combines whole-head magnetoencephalography (MEG) and magnetic
resonance imaging (MRI) technology.
MEG measures the electrical
function and MRI visualizes the structure of the brain. The merging
of these two technologies will produce unprecedented accuracy in
locating brain electrical activity non-invasively.
The problem with MEG is that when the technique
is used separately, the image accuracy can be compromised because of
the movement of the brain. Also, the image it provides may not be
accurate enough for precise brain surgery. In the past, it was not
possible to combine high-field MRI and MEG because their magnetic
fields interfered with one another.
Extremely sensitive magnetic
field sensors have now been developed, so scientists can now use the
new low-field MRI with a magnetic field strength of only a few
hundred-thousandths of that of the high-field MRI device. Fusing
these two technologies produces localization accuracy that was not
possible with MRI or MEG alone.
Academy Professor Risto Ilmoniemi said, "We expect that the new
technology will improve the accuracy of brain mapping of patients
with epilepsy. It may also improve the diagnosis of cancer patients
because the improved image contrast may facilitate the
characterization of cancer tissue.
"The innovative MEG-MRI device will allow brain imaging for new
patients, such as those with metal implants. Also, the silent and
open device will not scare children or make people feel
claustrophobic. In the future, this development can also reduce
costs as images can be obtained in one session rather than two."
Magnetic Resonance in Medicine: Hybrid ultra-low-field MRI and
magnetoencephalography system based on a commercial whole-head
neuromagnetometer. Article first published online: 17 Jul 2012