The stronger an MRI machine's magnetic field is, the better image resolution and refresh rates it is able to achieve. While most medical-grade MRIs today top out between 1.5 and 3 Tesla, the unit measure of magnetic field strength, GE has recently constructed a unit with the whopping power of 7 Tesla. But that's nothing compared to the power of the INUMAC.
Don't get me wrong, GE's 7T MRI is a medical marvel. It produces a magnetic field some 140,000 times more powerful than the one surrounding the Earth, and roughly five times the field strength of any other commercially available MRI and just slightly less powerful than the 8T magnets utilised by the LHC. Granted, there are some specialised MRIs that clock in at 9.4T, such as the Agilent system at the University of Illinois at Chicago, but those are designed for imaging rodents and small tissue samples, not the human body. And, as you can see in the comparison photo below, the difference in resolution and image clarity is quite obvious between 7T and 3T-calibre machines.
Picture: GE Reports
These GE machines are currently employed by IMAGO7 Research Foundation in Pisa, Italy where they are shedding new light on previously unstudied brain diseases such as Parkinson's. Using the 7T, a research team there was successfully able to image the brain's substantia nigra, which the medical community suspects is a key player in the development of the disease, to a much higher degree than ever before. This could lead to earlier detection and treatment options.
What's more, it's not like patients will have to fly all the way to Pisa to access this technology. "The 7T gives us the ability to distinguish brain tissues at a significantly higher level of differentiation," Baldev Ahluwalia, magnetic resonance manager at GE Healthcare, said in a press statement. "Since the 7T machines and standard clinical scanners share many of the same of components and electronics, we could then leverage the experiences and learnings from the high-performance 7T machines and optimise the 1.5T and 3T systems to look for the same tissue and disease differences - this could be a very powerful tool."
That's not all! The GE 7T could soon be eclipsed by an even more powerful MRI, which sports a massive, 11.75 Tesla magnetic field. Dubbed the INUMAC (Imaging of Neuro disease Using high-field MR And Contrastophores), this $US270 million machine has been in development since 2006 but is expected to finally reach market this September. While standard 1.5T and 3T medical imagers have a spacial resolution of around a square millimetre and refresh once per second -- enough to image about 10,000 neurons -- the INUMAC will provide a far more precise view. It will image an area of just 0.1 square millimetres at a rate of 10 images per second -- that's only enough to see about 1000 neurons at a time but should provide researchers with an unprecedented close-up view of the brain's inner workings. And in fields like Alzheimer's and Parkinson's research, this new level of magnification could unlock valuable new insights into the diseases.
The eight year-plus development time was necessary due to the incredible amount of engineering work that goes into building bleeding-edge technologies like this. For example, the wire used to create the INUMAC's magnet is a 170km niobium-titanium superconducting alloy tightly wound with micrometer precision. This wire will carry a 1500 amp charge when generating its strongest field and will have to be cooled to a temperature of just 1.8 Kelvin (-271C) in a bath of superfluid liquid helium. Another pair of 58km long coils are also being created to generate an opposing magnetic field and shield the rest of the hospital from the massive magnetic charge. And when operating at full strength, the INUMAC will generate a magnetic field sufficiently powerful to, should the situation arise, but used to suspend a 54-tonne tank. [GE Reports - IEEE - INUMAC]