Long Island man wearing 9kg-metal necklace dies after being sucked into MRI machine
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the magnet is always on,
I keep seeing that in the comments but isn't it actually an electromagnet?
Don't those need electricity to operate?I get it takes time to wind it up, been inside a few myself, but surely there's a kill switch?
Its an electromagnet that they have cooled down to 4 Kelvin with liquid helium. They take time to 'wind up' aka 'ramping up to the desired/max field strength capable of the magnet'. They do this slowly because the magnet itself can crack if done too quickly, and many components are still affected by the strong magnetic field due to Lorentz forces. Also many components may be classified as 'non-magnetic' but still have some small amount of magnetism and can move when subjected to the extremely high magnetic fields. So, if the magnet is 'quenched' (all the helium shot out through a tube in the roof) then that process occurs in reverse, VERY quickly, potentially destroying many things. So its not like 'cutting the power' because the power is stored around the magnet itself by supercooled components creating a superconducting situation. Nonetheless, in case of harm coming to a person, techs should absolutely hit the quench switch. Not sure what happened to allow this guy in that room though
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Reading more about the story I wonder how much of it is true
You can't just "walk into an MRI room", for one
When the MRI is working you definitely can't just walk in. Nobody is in there because of the radiation, so i doubt they just have an open door policy
Then, when there is an emergency like, you know, someone being strangled with a 9kg necklace on his neck by the machine's magnetism, you can press the kill switch that will quench the magnet by venting out all cooling liquid. This will damage the machine and is also a very expensive little joke, but it would save the life of that guy. Why didn't they do that?
It's a similar story to the guy that went into an MRI with a gun, causing it to fire and kill the guy.
Nobody is in there because of the radiation
What are you saying, there is no radiation in an MRI Scanner. It works with Magnets instead of X-Rays.
Nobody is in there because usually there is only one operator and this guy sits in the next room at his metal computer, which can't be in the MRI room, looking at the scan results. The doors are closed because MRIs are loud as hell.
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It's not an electromagnet, it's a superconducting magnet. And turning it immediately off makes it melt.
It's both! MRI magnets are electromagnets that are cooled down to 4 Kelvin using liquid helium. Once they reach those low temperatures, they become superconducting. This way, the magnet isn't gobbling up tons of electricity to stay at the desired field strength. Instead, the liquid helium needs to be replenished occasionally to keep it at superconducting temperature. Source: I work with MRI scanners.
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Isn't it an electomagnet?
it costs about thirty grand in helium every time you push it.
Oh, right, i forgot human lives have a price in the US.
Depends on the machine type. Closed bore machines (the vast majority) use supercunducting electromagnets that are surrounded by liquid helium that creates a very strong magnetic field. To demagnetize them requires dumping the helium.
Some open bore machines use electromagnets, but they're much less common and not as powerful.
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9 kilograms Necklace?! What kind of necklace is that?
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put one on the MRI. how many of them actually score a fatality?
Kind of like Tilikum, responsible for 3 of 4 known human deaths by an orca.
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Isn't it an electomagnet?
it costs about thirty grand in helium every time you push it.
Oh, right, i forgot human lives have a price in the US.
Its a superconducting magnet that cannot be instantly shut off. I am sorry that the physics of this makes you so angry.
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Yah the guy was 61 so it’s unlikely that Darwin would figure into the consequences.
People misuse the term "Darwin Award" a lot. It doesn't just mean someone died in a dumb way, it means they died in a dumb way before passing on their genes.
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Depends on the machine type. Closed bore machines (the vast majority) use supercunducting electromagnets that are surrounded by liquid helium that creates a very strong magnetic field. To demagnetize them requires dumping the helium.
Some open bore machines use electromagnets, but they're much less common and not as powerful.
So the helium itself becomes magnetized, is that it?
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It's both! MRI magnets are electromagnets that are cooled down to 4 Kelvin using liquid helium. Once they reach those low temperatures, they become superconducting. This way, the magnet isn't gobbling up tons of electricity to stay at the desired field strength. Instead, the liquid helium needs to be replenished occasionally to keep it at superconducting temperature. Source: I work with MRI scanners.
TIL, thanks
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Its an electromagnet that they have cooled down to 4 Kelvin with liquid helium. They take time to 'wind up' aka 'ramping up to the desired/max field strength capable of the magnet'. They do this slowly because the magnet itself can crack if done too quickly, and many components are still affected by the strong magnetic field due to Lorentz forces. Also many components may be classified as 'non-magnetic' but still have some small amount of magnetism and can move when subjected to the extremely high magnetic fields. So, if the magnet is 'quenched' (all the helium shot out through a tube in the roof) then that process occurs in reverse, VERY quickly, potentially destroying many things. So its not like 'cutting the power' because the power is stored around the magnet itself by supercooled components creating a superconducting situation. Nonetheless, in case of harm coming to a person, techs should absolutely hit the quench switch. Not sure what happened to allow this guy in that room though
So not just an electromagnet. Thanks, TIL.
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It would probably be quicker for you to look it up yourself because the answer is complicated to explain. But it's an electromagnet made from superconducting materials, and that is why it seems to violate your common sense.
Others explained it fairily ELI5 in this thread, thanks.
It's not just an electromagnet is the TL;DR. -
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A 6 pound necklace…
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So the helium itself becomes magnetized, is that it?
No, the liquid helium cools the magnets to the point where they become superconductive. As to how that works exactly, I do not know. I don't think I have the math for it.
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A 6 pound necklace…
1kg =2.2 pounds. more like a 20 pound necklace.
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I'm just going through the comments spreading MRI information (source: work with MRI scanners). There is no radiation danger from MRI.
Just a very strong magnetic field that makes having ferrous objects on your person a hazardous thing to do.
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So the helium itself becomes magnetized, is that it?
the helium is liquid, which it only is when it is very very cold.
The superconductor will keep it's magnetic field forever, as long as it's superconducting, and it will stay superconducting while it is very very cold.There is physically no way (as in, it is simply impossible, due to how our world works, not money, not people, not technology) to instantly "switch off" the magnet.
it needs to go above a certain temperature, to lose it's superconducting nature, and it needs to do it at a pace that doesn't dump a GINORMOUS amount of energy in this magnetic field instantly, because that would be even worse.
the fault here is in allowing anyone with any magnetic metal anywhere near an MRI. And whoever let that happen is going to have a very bad week.
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This was not Mr. T.
This was Mr. D Capitated.
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Isn't it an electomagnet?
it costs about thirty grand in helium every time you push it.
Oh, right, i forgot human lives have a price in the US.
The US is an outlier in how it charges prices for healthcare services.
But every country in the world has prices charged for cold liquid helium. It's very expensive to gather, process, store, and ship, regardless of what kind of health care economics apply in your country.
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Just a very strong magnetic field that makes having ferrous objects on your person a hazardous thing to do.
I recently tried spreading the word to other MRI folks about the dangers of 'magnetic eyelashes', which i learned was a thing from my fiance. Kind of suprised we havent seen any incidents with those, thankfully.
