Novel imaging method measures iron minerals in the living brain

A novel imaging technology—magnetoencephalography (MEG)—allows scientists to measure levels of iron-based minerals in the brain, which may provide insight into neurodegenerative disorders such as Alzheimer’s disease, reported researchers from Massachusetts General Hospital (MGH) in Boston.

MEG measures activity in the brain by detecting weak magnetic fields produced by normal brain electrical currents and ultimately quantifies magnetite in the human brain. Prior to MEG, these minerals could only be detected in postmortem brains, according to a release from MGH.

"The ability to measure and localize magnetite in the living brain will allow new studies of its role in both the normal brain and in neurodegenerative disease," said corresponding author, David Cohen, PhD, of MGH’s Martinos Center, in a prepared statement.

The study included 11 male patients who had undergone a baseline direct current MEG (dcMEG) scan prior to being placed into a powerful MRI scanner. The scan was used to produce an MR image and magnetize the magnetite particles in the brain. Several minutes later, a second dcMEG scan showed changes in the magnetic field that reflected to the size and shape the particles.

Results showed greater accumulations of magnetite in the oldest volunteers, most notably in and around the hippocampus—similar to results from postmortem studies.

Cohen and colleagues believe their tool will be helpful in identifying the effectiveness of magnetite in diagnosing, and even treating Alzheimer’s disease. However, they noted more testing is still needed.

"Studies could investigate whether the amount of magnetite in the hippocampal region could predict the development of Alzheimer's disease and whether treatments that influence magnetite could alter disease progression," the authors concluded. "While this new tool is now ready to be applied in studies of patients with neurodegenerative diseases, several improvements -- such as a new magnet, specifically built for this purpose—will be required to produce the precise measurements required for accurate diagnosis."

Results of the study were published in the journal Human Brain Mapping.