• 0x0@lemmy.zip
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    1 day ago

    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.

    • MangoCats@feddit.it
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      20 hours ago

      It’s a super conducting electromagnet, and if you quench it instantly pieces would be flying all over the room

    • exasperation@lemmy.dbzer0.com
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      1 day ago

      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.

      • MangoCats@feddit.it
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        20 hours ago

        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.

        • MrFinnbean@lemmy.world
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          16 hours ago

          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.

          • MangoCats@feddit.it
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            8 hours ago

            Well, the thing is, to kill the magnetic field within a few seconds would break the machine, so they don’t do that because it would up the cost of a shutdown from tens of thousands of dollars to several hundreds of thousands of dollars, and the downtime would go from several days to potentially several months.

            As it is they “quench” the superconducting electromagnet, which then requires a large amount of LH2 and electricity to get going again. I have heard numbers like $30,000 to get the magnet running again, not counting lost revenue during the many days it takes to get going.

            • MrFinnbean@lemmy.world
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              2 hours ago

              Well the thing is still that the weighted necklace pulled by 1.5 to 3 tesla towards the machine will also put it the machine out if comission from several days to several months.

              Also the down time of the machine depend from so many things like availbility of components, logistics and the actual damage happened, that even the most pragmatic operator could never calculate the price of the repair versus the value of the possibility of saving human life.

              FFS the saved 30k only buys pretty decent slightly used car. Its sick to even start to weight that kind of money to human life.

    • chiliedogg@lemmy.world
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      1 day ago

      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.

        • mavu@discuss.tchncs.de
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          1 day ago

          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.

        • chiliedogg@lemmy.world
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          1 day ago

          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.

    • AlexLost@lemmy.world
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      1 day ago

      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.

      • brendansimms@lemmy.world
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        1 day ago

        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.