A Weaker Cheaper MRI

The IEEE Spectrum reports on the development of an MRI machine that operates at a meagre 46 microTeslas (almost the same strength as the earth’s magnetic field , and a hundred thousandth of the field strength of conventional MRI machines, which typically operate at ~1.5Teslas). The stated advantages of these machines are:

Because it needs fewer costly magnets, a weak­magnetic-field MRI machine might cost as little as US $100 000, compared with $1 million or more for a standard MRI system ... But perhaps the most exciting thing about low-field imagers is that they can also perform another imaging technique, magneto­encephalography (MEG), .... MEG measures the magnetic fields produced by brain activity and is used to study seizures. Putting the two imaging modes together could mean matching images of brain activity from MEG with images of brain structure from MRI, and it might make for more precise brain surgery.

Low-field MRI has other advantages, says John Clarke, a physicist at the University of California, Berkeley.... “I’m personally quite excited about the idea of imaging tumors” with low-field MRI, he says. The difference between cancerous and noncancerous tissue is subtle, particularly in breast and prostate tumors, and the high-field strengths used in conventional MRI can drown out the signal. But low-field MRI will be able to detect the differences, Clarke predicts. A low-field MRI might also allow for scans during surgical procedures such as biopsies, because the weaker magnetic field would not heat up or pull at the metal biopsy needle

Now this seems a really exciting development in MRI technology – that would MRIs a practical medical device, rather than the hi-tech hi-cost curiosities they are now. And more than just the points mentioned in this article, the reason I found this technology so alluring is the potential of developing low cost, easily portable and deployable machines that can be used in the small clinics that dot the world, rather than today’s power hungry behemoths that cost a fortune to build and operate and that are available to less than 10% of the world’s population.