Magnets colour MRI scans

Microscopic magnets injected into the body might one day allow physicians to view magnetic resonance imaging (MRI) scans in colour.

According to researchers at the US National Institute of Standards and Technology (NIST) and National Institutes of Health (NIH), the micromagnets also could act as 'smart tags', to identify particular cells.

Unlike the chemical solutions now used as image-enhancing contrast agents in MRI, the NIST/NIH micromagnets have a precisely tunable feature - their physical shape - which allows them to return specific radiofrequency (RF) signals to the computers used in MRI equipment.The computer would then convert these signals into specific colours.

The magnets could also be coated so that they would attach themselves to different cell types, such as cancerous cells, allowing those cells to be highlighted on a MRI scan.

'Current MRI technology is primarily black and white; this is like a coloured tag for MRI,' said Gary Zabow, who designed and fabricated the microtags at NIST and, together with colleagues at the National Institute of Neurological Disorders and Stroke, part of NIH, tested them on MRI machines.