Palm-Size Superconducting Magnet Could Help Shrink MRI Machines

Magnetic resonance imaging (MRI) is crucial for performing a range of medical diagnostic applications, but the size and cost of the superconducting magnets and cooling systems used in MRI equipment make the machines stationary and expensive. Now, researchers at Japan's Railway Technical Research Institute (RTRI; Tokyo) have developed a superconducting magnet system that can fit in the palm of a hand. The compact magnet, in turn, could lead to the development of mobile imaging applications.

Inside a stainless-steel vessel measuring 32 cm high x 12 cm in diameter, the researchers achieved a magnetic force of 2.59 T, explains Masaru Tomita, RTRI's senior researcher, laboratory head, and project leader. "We managed to produce a strong magnetic field [within a device] the size of a water bottle." That is about twice the force generated by conventional high-precision MRI machines.

In addition to being small, the resin-impregnated magnet does not need expensive liquid helium, which is commonly used as a coolant in MRI systems. Instead, a drop of much more affordable liquid nitrogen does the trick. The device can also retain its magnetic power for several days. "Our magnet is both eco- and cost-friendly," Tomita says.

The original mandate of RTRI's applied superconductivity laboratory was to create technologies with automotive and train applications. However, the team branched off, entering the field of mobile medical imaging.

The research was published in an article titled "Development of a Compact, Lightweight, Mobile Permanent Magnet System Based on High Tc Gd-123 Superconductors," published in the Journal of Applied Physics.