The kill switch is VERY expensive to press, many thousands of dollars, and even when it does an “instant” magnet quench, by the time you hear the screams it’s all over anyway, the metal has landed on the magnet. Quenching the magnet will make it let go, but it won’t unbreak the neck bones.
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.
Not just the helium, there’s a considerable time spent “recharging” the magnet with electricity - many patients will lose access to MRI scan service during the multiple days it is down for recharge.
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.
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.
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.
I’m sure he was barely trained and had specific instructions to “never push that button!” When you whole life in the country is tied to your employment, it’s every moron for themselves.
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.
How was that allowed?
…while the machine was still working? And isn’t that the job of the technician anyway?
Those machines have a kill-switch for a reason.
I call this BS or a very incompetent technician.
Plus a Darwin award for the guy.
the high powered magnet is always on. it’s never safe to put metal near and MRI.
The kill switch is VERY expensive to press, many thousands of dollars, and even when it does an “instant” magnet quench, by the time you hear the screams it’s all over anyway, the metal has landed on the magnet. Quenching the magnet will make it let go, but it won’t unbreak the neck bones.
Couple things:
The magnet is ALWAYS on.
The “kill switch” takes about five minutes to actually deactivate the magnet and it costs about thirty grand in helium every time you push it.
Not to mention it’s not renewable. Once it his the upper atmosphere, you can’t get it back.
Isn’t it an electomagnet?
Oh, right, i forgot human lives have a price in the US.
It’s a super conducting electromagnet, and if you quench it instantly pieces would be flying all over the room
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.
Not just the helium, there’s a considerable time spent “recharging” the magnet with electricity - many patients will lose access to MRI scan service during the multiple days it is down for recharge.
Dont they loose the access to the machine anyway for few day? Im under impression metal slamming to the machine usually breaks it pretty good.
And in fact, doesn’t the US have most of the world’s supply of helium?
Its a superconducting magnet that cannot be instantly shut off. I am sorry that the physics of this makes you so angry.
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?
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.
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.
I’m sure he was barely trained and had specific instructions to “never push that button!” When you whole life in the country is tied to your employment, it’s every moron for themselves.
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.
TIL, thanks