I don’t get it - the 11T image has vastly more information than 3T image. Are you saying all that extra information is not helpful when trying to detect tiny tumors or clots?
I think they are saying that even with much better MRIs the limiting factor is finding a radiologist to interpret the image, and the costs of treatment.
I’ve never had a problem finding a radiologist in US and my insurance covered something like 80% of my last MRI. I think I paid ~$300 for it. I would gladly pay double that for a more reliable detection.
I can do thin slices on a 3T just fine. They don’t usually help, with the standard 3mm providing plenty enough information. We do the odd scan that is 0.5mm slices.
If I show a lesion that’s <1mm, will anyone do anything about it? Watchful waiting seems likely.
The question is ‘do thinner slices improve diagnostic accuracy?’ I’m sure they do… to a point.
A monster of a machine like this will be research based and being doing dti etc at extreme resolution. Not that helpful clinically, very useful to the researchers.
Getting more people scanned is much more of a problem than getting more scanning on the same cohort.
Not OP, but I am a radiologist, and that 3T image is not representative of a state-of-the-art clinical scanner. The 11.7T does have extremely high spatial resolution but contrast resolution is compromised.
As others have said the clinical utility of >3T is very dubious, and most real world MR advances in the last 5 years have been AI (DL/ML not generative) reconstruction for lower field strengths.
That high a field strength has significant safety concerns, particularly for implants and pacemakers etc.
The safety aspect you point to is just so painful.
I was looking at a 5T scanner from United Imaging (interesting stories there…). Is there a single implant that’s been tested for these novel magnets? Checking out implants is painful enough at 1.5T and 3T.
I have to imagine that ReBCO magnets being made in bulk will substantially change the economics of MRI machines. It's likely that new business models or market segments now become feasible.
I think the magnets are much stronger and cheaper, which will make MRI machines much cheaper, allowing more uses that wouldn't have been economical before.
If they were cheap enough your local urgent care could have you get one every time you twist your ankle or whatever.
In places in the world where those rules don’t apply, access and cost is still problematic.
There is a lack of staff, the hardware is expensive and the bill payers (insurance and national health services) don’t really want everything scanned all the time.
That can't be the reason. Not all states have CON, and they're not pure regulatory capture. From TFA:
"Competition is a good thing except when one of the competitors is free from the onus of being required to service everyone who walks through the door."
"states that have repealed CON laws have had other consequences, including doctors over-prescribing services because they're being forced to maintain a bottom line."
> If they were cheap enough your local urgent care could have you get one every time you twist your ankle or whatever.
More importantly, if MRIs were as cheap as X-Rays are, they could revolutionize early cancer detection, especially when paired with AI. The problem is that even if they are cheap, they are slow. And radiologists aren't scalable.
I find MRI machines absolutely fascinating. If I was mega-wealthy, I would have one at my house to perform independent research with. Even the math involved in the inverse problem of how images are constructed from the raw signals is super interesting.
I agree with you that these should be all over the place; I think they would be a great boon for preventative medicine.
Yeah, but the false positives are a separate issue to solve. That would be like saying the introduction of the car has led to thousands of deaths by automobile — accurate, but not the whole story of why we keep them around.
True, but not serious, positives. Take the following example.
Right now in your brain you have a small cancerous lesion. If you don't know about it, your body will heal it and you'll never know that you had it.
But, if I show you a picture of it, suddenly you're filled with stress chemicals causing your immune system to work poorly. The cancer grows into outwardly detectable illness. You now require treatment for a deadly illness.
Real positives aren't much better! A friend of mine worked with an MRI researcher and therefore had an opportunity to undergo a number of elective MRIs for free. They consistently turned up minor issues (labral tears, bone spurs, etc.), even in body parts that he assumed were perfectly healthy. Bodies are complicated, and we can compensate a surprising amount before things become an problematic. Learning about all of these isn't always helpful, and can actually cause harm (e.g. stress) once made aware.
not at all whatsoever. however if you have gadolinium injected for contrast some people have problems with that. but the magnetic field itself doesn't affect you negatively on its own
We don't have any evidence they are dangerous. There are some phenomenon like magnetophosenes. You could also look up what a magnetar would theoretically do to a body, but nobody is getting close to one of them anytime soon.
Very strong constant magnetic fields don't seem to be dangerous (at least at the kind of levels MRI machines work at, which are within an order of magnitude of the strongest magnets on the planet). A very rapidly changing strong magnetic field can be dangerous, because it induces currents in your body, like in your nerves. There are safety limits (very conservatively set) in MRI machines on how quickly they adjust magnetic fields, as if they were to really go for it there's a risk of heart problems (in the moment, it's not like CT scans where more exposure means more risk later in life).
A magnetic field is not radiation. The changing RF fields used are, but they're not ionizing radiation (the dangerous kind) like that found in CT scans. The radiation used in MRIs should not be able to induce any changes to the molecular structure of your body, but RF burns can still be a risk. (Clothing and even tattoo ink can exacerbate this, fascinating!) The biggest risk seems to be being bonked by loose medical equipment, but I don't think that's what you were asking about.
There is a theory that there could be unexplored effects of RF exposure. For example, we can see that glucose metabolism increases in brain tissue exposed to RF. That could be the end of it, or there could be consequences to that under the right conditions. We don't know yet.
An MRI is just a great big magnet (generated by a superconductor that is held at low temperatures by liquid helium).
From the safety section of the wiki: "Since MRI does not use any ionizing radiation, its use is generally favored in preference to CT when either modality could yield the same information... MRI uses powerful magnets and can therefore cause magnetic materials to move at great speeds, posing a projectile risk, and may cause [extremely rare, perhaps fatal] accidents."
If you've had a PET scan, then you've been exposed to antimatter (anti-electrons) for Positron Emission Tomography (which ends up as gamma ray radiation).
I was in an MRI recently that gave me crazy muscle spasms in my back synchronized with the MRI pulses. It is apparently semi common to get that type of thing, but it was unnerving to have the machine seemingly take control of my nervous system.
Anyways this was an old machine going into ‘retirement’ next week i was told. I wonder what my response would be to 11T magnet.
I've long thought it's a wonderful coincidence that there's not enough magnetic material in the average human to make MRI dangerous to the point of uselessness. Good to know what to look out for if I ever get a scan.
I wonder what the mechanism that caused that was. Induced current, maybe.
There are safety limits on MRI machines (more related to how quickly the fields change as opposed to their absolute strength) so that they don't stop your heart. I'm not suprised they can have some noticable effect below that.
> Time-varying gradient fields may induce currents in nerves and muscles, causing tingling, tapping, or twitching. Patients must be instructed to alert staff immediately when they experience such sensations.
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[ 2.9 ms ] story [ 112 ms ] threadhttps://www.cea.fr/english/Pages/News/world-premiere-living-...
Or for French speaking people:
https://www.cea.fr/Pages/actualites/sante-sciences-du-vivant...
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I wonder how much the resolution would increase if we went from 11T to say 50T?
Various groups are chipping away at low field magnets with the aim of improving access, and their results are impressive.
Are you a radiologist?
I can do thin slices on a 3T just fine. They don’t usually help, with the standard 3mm providing plenty enough information. We do the odd scan that is 0.5mm slices.
If I show a lesion that’s <1mm, will anyone do anything about it? Watchful waiting seems likely.
The question is ‘do thinner slices improve diagnostic accuracy?’ I’m sure they do… to a point.
A monster of a machine like this will be research based and being doing dti etc at extreme resolution. Not that helpful clinically, very useful to the researchers.
Getting more people scanned is much more of a problem than getting more scanning on the same cohort.
As others have said the clinical utility of >3T is very dubious, and most real world MR advances in the last 5 years have been AI (DL/ML not generative) reconstruction for lower field strengths.
That high a field strength has significant safety concerns, particularly for implants and pacemakers etc.
I was looking at a 5T scanner from United Imaging (interesting stories there…). Is there a single implant that’s been tested for these novel magnets? Checking out implants is painful enough at 1.5T and 3T.
If they were cheap enough your local urgent care could have you get one every time you twist your ankle or whatever.
There is a lack of staff, the hardware is expensive and the bill payers (insurance and national health services) don’t really want everything scanned all the time.
"Competition is a good thing except when one of the competitors is free from the onus of being required to service everyone who walks through the door."
"states that have repealed CON laws have had other consequences, including doctors over-prescribing services because they're being forced to maintain a bottom line."
Also, other countries exist.
More importantly, if MRIs were as cheap as X-Rays are, they could revolutionize early cancer detection, especially when paired with AI. The problem is that even if they are cheap, they are slow. And radiologists aren't scalable.
I agree with you that these should be all over the place; I think they would be a great boon for preventative medicine.
It’s not as good as one would hope. False positive cause misery.
True, but not serious, positives. Take the following example.
Right now in your brain you have a small cancerous lesion. If you don't know about it, your body will heal it and you'll never know that you had it.
But, if I show you a picture of it, suddenly you're filled with stress chemicals causing your immune system to work poorly. The cancer grows into outwardly detectable illness. You now require treatment for a deadly illness.
(I have no idea if magnetic field == radiation, I was just told from my ENT that doing too many CT scans can be risky)
I guess some materials in the body have some response to magnetic fields
https://www.reddit.com/r/AskPhysics/comments/3w03pj/comment/...
https://www.youtube.com/watch?v=E-yHv91Y_oI
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2705217/
https://en.wikipedia.org/wiki/CT_scan
An MRI is just a great big magnet (generated by a superconductor that is held at low temperatures by liquid helium).
From the safety section of the wiki: "Since MRI does not use any ionizing radiation, its use is generally favored in preference to CT when either modality could yield the same information... MRI uses powerful magnets and can therefore cause magnetic materials to move at great speeds, posing a projectile risk, and may cause [extremely rare, perhaps fatal] accidents."
https://en.wikipedia.org/wiki/Magnetic_resonance_imaging
If you've had a PET scan, then you've been exposed to antimatter (anti-electrons) for Positron Emission Tomography (which ends up as gamma ray radiation).
https://en.wikipedia.org/wiki/Positron_emission_tomography
Anyways this was an old machine going into ‘retirement’ next week i was told. I wonder what my response would be to 11T magnet.
I wonder what the mechanism that caused that was. Induced current, maybe.
(peripheral nerve stimulation)
https://www.jospt.org/doi/10.2519/jospt.2011.3906