A technique for magnetic resonance imaging (MRI) could provide fast brain scans at a fraction of the cost of conventional machines.

Most MRI scanners require large magnets to generate a strong enough magnetic field to penetrate soft tissue. A team led by Matthew Rosen at Harvard Medical School in Boston, Massachusetts, has demonstrated a way to capture an image using magnetic fields that are 450 times weaker than those used by current machines, and at one-twentieth of the cost.

The team engineered a radio-frequency coil that could pick up the faint radio signals generated as a result of the weak magnet and used data-collection techniques that speed up image reconstructions.

Although the resulting images have a lower resolution than do those from large MRI scanners, they can still reveal major abnormalities such as signs of traumatic brain injury or stroke, Rosen says.

Sci. Rep. 5, 15177 (2015)