The most powerful MRI machine in the world is nearing completion. The new instrument will be able to generate 11.75 Tesla, a field strong enough to lift 60 metric tons. Squeezing out those last few Tesla (the previous record for field strength was around 9.4) requires extraordinary precision in the design and manufacture of the superconductor magnets at its core. As a recent article in IEEE Spectrum reports, fields of this magnitude are stronger than those used in the Large Hadron Collider which famously discovered the Higgs boson. As a research tool, a machine like this would allow the brain to be imaged in unprecedented detail—a voxel size of .1mm as compared to 1 mm previously. But as medical device makers struggle to design implants that won’t move, heat up or otherwise fail in fields of that strength, the opportunity for new discovery in the brain, will by guided also by a few new challenges to be overcome.
MRI machines normally image the relatively strong signals associated with the nuclei of hydrogen. With higher field strengths it is possible to image signals from sodium or potassium, the ions that are also among the most mobile in carrying the charge associated with spikes in neurons. An area of 0.1mm still might have over 1000 neurons so this technology is not going to be imaging neuron activity individually. It may however, provide recent efforts to decode the private imagery associated with our inner thoughts and dreams with much greater accuracy than current methods. While a recent paper in Nature contains an air of optimism regarding the progress of the decoding algorithms used in these kinds of studies, cautionary tales regarding the interpretations of the results still abound. Via World’s most powerful MRI gets set to come online.