MRIs and Sir Peter Mansfield
Do you know Peter Mansfield? Don’t feel bad if you say no, because I didn’t either until a friend notified me of his recent passing. It turns out he is a Nobel Laureate, having won the prize for medicine or physiology in 2003, for his work on understanding and developing the physics behind magnetic resonance imaging (MRI). Most everyone with multiple sclerosis is personally familiar with the MRI because it is used for diagnosis of the disease and for tracking the progression.
Sir Peter was British, hence the title, and he worked at the University of Nottingham for his entire academic career as a researcher and professor of physics. Just a few decades ago, the MRI machine had not been invented until Sir Peter and his team worked out the physics, understanding how very strong magnets can be used to make images of our body.
Physics and MRIs?
What does physics have to do with MRIs? Everything!! The images that we see from our tests don’t come from snapshots but rather the interpretation of the data returned from rearranging of the protons in our body as we undergo the MRI. Protons are in the water in our body. The complexities of how an MRI works are well beyond my limited space here to explain and my own mental abilities to comprehend. I would suggest you read Magnetic resonance imaging or What is an MRI? to better understand the details. But in short, when the big magnet of the MRI is turned on, all of the protons in the area being studied line up in the same direction, thanks to the magnetic pull. When the magnet is turned off, the direction of the protons return to their previous positions in alignment with the natural magnetic field of the earth, and somewhere in that process there are signals captured by the machine and sophisticated software that help to form a ‘picture.’
Sir Peter worked through the proton alignment computations and was the first person to volunteer to be in the MRI machine for testing in 1977. Until the first test was done, it wasn’t known how the body would be affected or even if the protons (contained in all the water in our body) would return back to their normal position. Even recently when I was volunteering in research in a super strong magnetic field, 7T MRI*, there were people who warned me about the dangers of a force that strong. Except for people who are claustrophobic, we don’t think much of the MRI test because it is known to be safe and has no lasting side effects like an x-ray might have.
MRIs and Diagnosing MS
Today, the MRI is the most relied on diagnostic tool for MS after the clinical exam, and its use changed the course of multiple sclerosis treatment forever. Sir Peter shared the Nobel prize for medicine or physiology in 2003 with an American chemist, Paul Lauterbur, who was also working on the same approach to use physics to create images of the body.
An obituary in the New York Times offers more of his story and why we are all indebted to Sir Peter for his work. I’m glad my friend told me about his passing and I had this nudge to learn more about the man and his contributions to my MS care.
Wishing you well,
*The T in the strength of MRIs denotes their Tesla strength. It is named after Nikola Tesla, from Hungry, who discover the magnetic fiend of the earth and is considered the founder of modern physics. Magnet strength is also measured in a unit called gauss. 1 Tesla= 10,000 gauss. The magnetic pull of Earth is about 0.5 gauss, and all of the MRI magnets are much more powerful than the earth’s gravitational pull.