I don't know anything about MRI machines, but couldn't they be built with high temperature superconductors and use liquid nitrogen? If anything this feels like a cost issue not a pure technology issue...
> If anything this feels like a cost issue not a pure technology issue...
It IS a technology issue. High-TC superconductors are basically ceramics, meaning that they are brittle. And a good simulation of MRI experience is being inside a trash can that other people hit with baseball bats.
We are only now starting to get high-TC superconductors in the form of tape, but it's not yet ready to replace low-TC superconductors.
BTW, it's also the reason we're hearing about so many new fusion startups trying to utilize it. It _should_ provide an order of magnitude cost decreases compared to liquid-helium. But it's still something that only startups are using.
The largest NMR spectrometer you can buy today uses high-temperature superconductors and classical ones, but it still cools everything down with liquid helium. As far as I understand you can push more current through the high temperature superconductors when you cool them down more.
NMR spectrometers work on essentially the same mechanism as MRIs, just in a very different form factor. It might even work for MRIs without helium because they have a much lower field (~3-6T) compared to the ~28T of the highest field NMR spectrometer.
The high-temperature superconductors are still pretty new for this field, it took a while to figure out manufacturing them on a scale and quality that could be used for these large magnets.
It's good enough for _startups_ working on fusion reactors, they can tolerate a bit of risk. But not for established companies making safety-critical equipment.
And modern MRI machines are not that expensive either, mass production made them surprisingly affordable. A top-of-the-line machine is around $700k, and mid-range devices are $300-$400k (and now I want one in my backyard...).
So the savings on high-TC supeconductors would not be that impressive overall.
I don't know if this is the only reason, but superconuctors have a critical magnetic field that is also related to temperature (higher temp = lower magnetic field). So even if a material is superconducting at liquid nitrogen temperature, that doesn't mean it can produce a strong enough magnetic field for an MRI at that high a temp.
The simpler thing to do seems to regulate helium use in birthday balloons.. not a hard choice between life saving diagnostics and large numerically shaped balloons..
I have 3 foil party balloons still inflated after 2 months and 3 days. I left them by the window as heat from the sun provides kinetic energy to the helium atoms to improve the balloons longevity. These three balloons have provided me with enough joy to keep me inside staring at them all day not outside at risk of injury which ultimately leads to an unnecessary MRI.
My father turned 80 and they kept his mylar balloon around in the living room for at least 18 months. It's one of the few things that survived the cat.
Gas pressure is the atoms/molecules bouncing off something else. If the atoms have more energy, then they impart more energy into whatever they bounce off (inside of the balloon), which essentially means higher pressure i.e. the balloon appears inflated again. Until the sun goes away and the OP's party dies for a time. :)
> "Balloon Grade" Helium represents a slightly impure Helium. While there is no scientific definition of this quality, it is often accepted that the purity of "Balloon Grade" Helium is around 99%
Sounds high, but not pure enough for MRI applications, and it isn't currently economical to reliquefy without shipping it to a processor.
> Manufacturers have stated that this wasted helium is considered a ‘recycled product’ as it would have been lost to the environment had it not been captured and re-purposed. If the balloon market demand declined, manufacturers would have to re-evaluate other markets and consider the possibilities of re-liquefying it. Re-liquefying is currently considered uneconomical from the locations of where the filling application take place.
why don't you fund the life-saving diagnostics enough that they can outbid birthday party planners? i'm not convinced birthday party planners are rich enough anywhere in the world that this is an actual problem
It IS a technology issue. High-TC superconductors are basically ceramics, meaning that they are brittle. And a good simulation of MRI experience is being inside a trash can that other people hit with baseball bats.
We are only now starting to get high-TC superconductors in the form of tape, but it's not yet ready to replace low-TC superconductors.
BTW, it's also the reason we're hearing about so many new fusion startups trying to utilize it. It _should_ provide an order of magnitude cost decreases compared to liquid-helium. But it's still something that only startups are using.