Brain imaging by functional MRI 2.0

A feature in Nature describes the growth of functional magnetic resonance imaging (fMRI) for studying the brain, starting with its first report 20 years ago. This non-invasive technique produces images by taking advantage of the magnetic properties of oxygen-rich blood, revealing blood flow to active regions deep within the brain. It is allowing scientists to build up a picture of brain networks.

fMRI instruments with increased resolution have been assembled using stronger magnets, but there is an upper limit to magnetic strength, beyond which the patient suffers dizziness and side effects, and the images begin to display artefacts. To get around this, new ways of increasing the signal are being tried out, like injecting agents into the blood which are easier to detect. But the greatest challenge appears to be moving the technique into general clinical practice.