Long Island man wearing 9kg-metal necklace dies after being sucked into MRI machine
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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.
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Surely dialed down in between scans?
No. They are usually superconducting magnets in persistent mode:
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take hours to start or stop
You mean they're in constant operation the whole shift?
Surely dialed way down in between scans?The dectector and the variable field (that induces the localized measurable changes) stop between scans, but the static magnetic field is kept up.
As long as you keep up the superconductitvity there is basically no electrical loss in the coils. Dialing the magnetic field down would require pulling out the energy, and reinjecting new energy to get the field back up. That's the slow part, because injecting current quickly would heat the coil above superconductivity, leading to a quench.
I'm not sure how energy is withdrawn in the ordinary shutdown procedure, but I expect it is exchanged into heat and vented to the outside air in some way, rather than reinjected into the grid in a usable form. (The latter would require an inverter to turn the DC back into AC synchronized to the grid, probably would increase complexity by too much). So I suspect it would be wasteful too.
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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.
I'm just going through the comments spreading MRI information (source: work with MRI scanners). There is no radiation danger from MRI.
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take hours to start or stop
You mean they're in constant operation the whole shift?
Surely dialed way down in between scans?No, the magnets are just as dangerous when scans aren't happening. They are always on.
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RIP Mr T.
That's some Final Destination shit right there.
One and only one headstone that includes a mention of a big ass magnet as the cause of death in rap format.
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So, if the MRI spins at 12 RPM, does the dude also spin at 12 RPM?
Asking for a friend.
Just going through comments spreading MRI information (source: I work with MRI scanners). Nothing is spinning inside the MRI machine. CT scanners have an internal spinning component, but MRIs do not.
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Surely 9kg necklace isn't something you can just sneak around with, how was he allowed to get close enough to an MRI machine in the first place wearing it?
I would need an entourage of physiotherapists if I had the bling to roll with a 9kg necklace.
Imagine how dope my rhymes would be though. A man can dream....
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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.
