Interesting, I always thought that the MIR machine was an electromagnet of sorts that could be powered down when not in use. If an electric current doesn't create the field, what does?
@cenzo188 MRI machines use superconducting electromagnets. However turning them off would result in a quench of the magnat. When this happens, a particular spot is subject to rapid heating, which raises the temperature of the surrounding regions, which leads to more heating in a chain reaction and can damage the magnet (YBCO is pretty expensive :P)
i dont know what people are thinking but... gee can you turn a magnet off? cuz i cant. this is a very expensive machine. that would suck to have to ruin the magnet over a chair. thankfully this one was alright.
@CrazyHorsies The power can be turned off but I think it takes quite a while for the machine to power down completely. My guess is it was off but the magnet hadn't fully discharged..If it was at fully strength I'm not sure they could've budged the chair at all Thats why you see him using a block of wood to pry it off
I walked in to the magnet room once and forgot that I had my cell phone in my pocket. Need I sau more? Fortunately there wasn't anyone on the magnet. My cell was dead the very next day. LoL
If you are about to go for an MRI scan DO NOT WATCH THIS STUFF!!!!!
It is less safe not to have it done when you may have a brain Tumor that needs treatment. I am waiting for my results from this unpleasant experience but tell you what I am so glad science gives me the option to try and get some treatment!
Don't bury your head in the sand and don't die of ignorance!!!
ofcourse its horroble u cant switch of such a magnet and such a machine is importend needed in a hospital even the danger of the chair for the ppl then it flys again in machine ... but the got him out without someone gets hurt
its not good to do that with large objects as it could bend properties of the magnet while pulling and distort future images.. but i undertand why some engineers would do this.
that particular one can be turned off and on, but it takes time and money to do that. The way they did it is not the right way to do it, ramping the magnet down and then up again would be the best way.
Because it would cost over $100,000 to quench the magnet and repower it back up not to mention the days of down time where the machine can make $3,000 per hour.
It is expensive because the magnet is a supercooled magnet that is soaking in liquid helium which is very expensive. It works by soaking the magnet in the helium then passing a current through it, then you turn the electirity off and due to the magnet being near absolute 0 the current stays in place, but once it heats up a little bit the helium boils off and the magnet shuts down. It costs 1000s to refill the chamber with helium.
@LukeL007 Actually you cannott repower an MRI after it is quenched. It needs to be replaced and it is dangerous and a ton of helium which is already limited will be wasted. You may be thinking about ramping the machine down.
No, it's an electro magnet - and that is definitly not permanent. But it is quite expensive to remagnetise the electro magnet after it has been demagnetised.
It doesn't work that way, look up supercooled magnets to see why. A MRI is one giant magnet and a couple of smaller magnets. The giant magnet is a supercooled magnet that requires no constant stream of electricity, as long as the temp is near absolute 0 which is expensive to maintain.
@ Envergure.. they could have ramped the magnet down and then ramp it back up, this would only have lost them a small percent of the helium, however i imagine they did that to get the customer back up and running as the tooling needed to take the current out of the magnet safely is very heavy and takes time to get to site. If the magnet heated up and quenched (where the liquid helium turns to gas and leaves the magnet) it could then be re-filled and re-powered but very expensive process.
lol reminds me of when my Mom forgot to take her hair clip out when I had an MRI, she kept feeling this painfull tug on the back of her head and when she realised it was the clip and took it out it went flying into the MRI right near my arm, she grabbed it real quick but still we heard the tech guy say ' I saw that' then laugh lol ahh memories from the MRI
Contrary to what some films that feature MRI scanners seem to portray, they're not electromagnets that can be turned on or off. It's super conducting and essentially permanent. To switch it off you'd need to quench it, which can permanently damage the magnet so isn't advisable. (also see Mednovotob's comments below)
@armondikov its a superconductive magnet, I work for the company, it can be RAMPED DOWN (current taken out of the magnet with a power supply takes about 1 hr) and the magnet would not me a magnet anymore without quenching it and only boiling off about 2-4% ramped up and down (3 hrs total) .. the problem is the customer would have been unable to use the machine until they got the power supply to the site (1 day or overnight) so thats why they probably just went and pulled it out like that.
Plus, these "closed" or so called high field MRI scanners need to be cooled permanently by liquid helium. (Approx -270 C. degrees) The helium is constantly rotating-floating in the gantry. They never turn an MR off, there is a dormant status, but the magnet is always active indeed.
this magnet is not a permanent magnet.. its a superconductive magnet.. quenching it does not permanently damage the magnet, but should only be done when its a safety issue due to the cost of getting the magnet back up and running. Liquid Helium is expensive.
@shinyedgestudios its a superconductive magnet, I work for the company, it can be RAMPED DOWN (current taken out of the magnet with a power supply takes about 1 hr) and the magnet would not me a magnet anymore without quenching it and only boiling off about 2% of the helium that is in it. then it can be ramped up again (one hr) and again lose about 2% .. the problem is the customer would have been unable to use the machine until they got the power supply to the site (1 day or overnight)
@shinyedgestudios It's not a permanent magnet, like the kind that you stick onto your fridge door. It is superconducting (close to a perpetual motion machine for electricity) and it does take a lot to 'turn it off', but it's not permanent.
If it was an ELECTRO-Magnet I did. And I know there are permanent magnets in the thing, however they have juice going to them which increases the field; just like an Electromagnet. If you were to turn off the power, the field strength would be a great deal less. Someone told me they do not shut them down due to the cost of rebooting them. I am not aware of any permanent magnets able to generate such a field without additional power and some coils in them.
The magnets are electromagnets that are super cooled with liquid helium to make the coils super-conductive. This makes it extremely expensive to power down because of the cost of more liquid helium.
That's why many professional and accrediting bodies have recommended using the new ferromagnetic (only) detector systems to screen everyone and everything that goes into the MRI room (to keep ferromagnetic materials out). Check out my videos, including one that features Dr. Emanuel Kanal, noted MRI safety guru.
For something like a chair, with a fair amount of ferromagnetic material. Would that cause changes to the magnetic domains on the permanent magnet, resulting in the facility having to "re-tune" the parameters for the machine? Or can the machine compensate when it shims at the start of the scan?
Some people look at the outside of the chair and see plastic and cloth and think that that's what it must be made of. Others know that it has ferromagnetic material inside, but think that they can bring the chair 'just inside' the doorway and everything will be fine.
Neither option is smart. Better to know for sure by using one of those new ferromagnetic detectors to make certain.
Its also possible they thought they'd be "ok" with the chair off to the side, since the magnet is actively shielded. The field strength only starts to ramp up (exponentially? cubically?) near the bore. Either way, someone was careless.
Aint these video guys fools? Anit common sense dictate that the MRI machine must first be turned off (in order to eliminate its strong magnetic field) before the seat can be easily removed? Or was this a deliberate stunt to demonstrate the magnetic field power of the MRI machine?
I have seen an MRI machine in a hospital and I dont think it cost anything turning on or off this machine. It is more or less like turning on/off an X-ray machine. It costs next to nothing. I think this video was a 'public' stunt to whila away stress or to demonstrate the magnetic power of the MRI. Assuming you're correct, then safety precautions (like no loose metalic objects nearby) etc were ignored and cost should be the lesser evil.
It sits idle but when it actually scans the field gets way stronger as others have pointed it it does cost a lot to shut down completely. Once it's running it doesn't cost as much to keep it on as the huge amount of current to get it started.
Most MRIs (certainly the one in this video) are electromagnets. But the electricity bill to run such a magnet would make an already expensive machine much more costly to operate. The fill it with liquid helium which makes the wires used for the electromagnet superconducting. The electricity goes in, and - as long as you keep it at 4 degrees Kelvin - never comes out. That's why you can't just switch it off. You have to boil the helium to get the current to go away fast.
O.K. that is a reasonable explanation. But i also thought there might be an 'emergency turn off' mechanism that might help 'bleeding of' all the current (perhaps to earth) of if this aint possible, then they should simply leave the magnetized seat as it is until the magnetic field reduce enough (via incremental boiling of the helium superconductor) for it to be removed (I think).
There is an emergency button... called a 'quench button' which triggers a heating element inside the liquid helium. MRI's are like Stradivarius instruments. Think of quenching an MRI as cutting all the strings on a million-dollar cello at once with a pair of bolt-cutters. Sure, they're just the strings, but do you really want to risk doing structural damage to the instrument? Also, about waiting, MRI providers count on $1,000 / hr in revenue. Waiting is a very expensive option.
Just so you know, unless your in the Military you need to take a 12 month course for MRI (a stand alone school. You don't need to be RT certified for MRI. MRI pays well, but is a boring job. With a constant pinging it sounds as though you are in a sub all day long. If your considering becoming an MRI tech, ask your local hospital to sit in for a day to get a grasp on what your getting yourself into.
The machine uses helium to cool down the system. I that helium has to be changed if restartet. Something like that, i a m actually not 100% sure. my radiograpy teacher told me.
Wow! if that's the case, then there must be a way of turning off the huge magnetic field of this MRI machine without turning off the machine. This MRI machine resemble the ones I see in some hospitals which are used (i.e. turned on and off) relatively frequently. I do not think $20000 is required for each turn on / off.
Only in emergency situacions. I think you have to take out the helium so the magnetic field will be eliminated immediately. something like that. if u just power it off normally i think it will take alot of time for the field to go away. Try ask at the hospital, i will do the same:)
I think the whole confusion here is what is off. They aren't really ever off they are either idle or in use when in use there is more stuff going on and more power being used but when idle it still keeps gasses pumping and what not.
There are two normal ways of shutting the magnetic field off.
An emergency ramp down or quench and a standard ramp down done by service personnel with a special ramp power supply. The first way is done only when there is a patient at risk, takes a short amount of time (<1 minute) and is costly since most of the liquid helium will be lost. The second method takes an hour or so but only about 3% of the liquid helium volume will be boiled off.
The question is what does 'off' mean? The big magnet (that sucked the chair in this video) is never off. During the exam, there are other parts of the MRI (the parts that make the noise) that depend on the big magnet being on. These other parts (gradient fields and RF transmitters) can be turned off with a switch, so that the machine can't image. That, however, doesn't mean that the magnet is off. That's the confusion.
Ok; in other words, the powerful magnetic field of the MRI machine would have to weaken gradually as the temperature of the superconducting helium coolant is gradually made to increase which might be a long time to occur.
Actually, no. Superconductivity of the coils dies very rapidly as the temperature rises just a few degrees. The (emergency) quench button activates a tiny heater inside the liquid helium vessel, but this small amount of heat is all that's needed to reach the tipping-point at which the helium boils and the coils stop being superconducting (which means electrical resistance, which means heat, which means more resistance and more helium boiling...).
Yes but the progressive electrical resistance build up will lead to progressive current reduction and progressively weaker magnetic field until the latter is weak enough to 'release' the stuck iron seat (though we know this may cause the helium to boil more).
Yeah, why aren't you as smart as "bananabuger"? Just note his high vocabulary, "nucular?" "asplosion?" and "queanch???" wtf?? What a dumbshit, telling you to get a brain when he lacks the ability to spell simple words.
As for the helium lost in a UNquench, its about $875-1250, for 250 liters being dumped out of the system. It would cost 3-4 times that in any other G8 country.
Oh, yeah, the machines leak too, so the room, if the hospital isnt profit bound, will have helium detectors in that room that will go off with a major leak...
I work at a "poor" hospital. All the sad saps in MRI have to determine a Helium leak is to listen for in increase in pitch of thier co-worker's voices! lol j/k
The word quench make no sense absolutely because quench means to rapidly cool. The emergency shut off drains the coolant, thus heating the superconductor and creating resistance which makes it non magnetic. More like unquenching.
Ramping either bleeds coolant slowly to demagnetize the coil or charges the coil while adding coolant in proportion so that resistance nears 0.
Consider that there is no 'heating' or 'cooling', just transfer of heat energy. If you quench a piece of steel from a forge in a bucket of water, you are rapidly transferring the heat from the steel into the water. Steel cools, water heats and boils.
yeah im getting that here by reading the rest of ppl's comments you need to quench it down or something or it might send out an EMP pulse and kill all technology in a large radius
yeah i just got one today and after hearing what its capable of i was a lil scared lol. but yeah when something goes wrong with them things it gets scary lol
There are 3 solutions. 1st is what these guys did (not recommended). There's a quench (mentioned earlier) which 'turns off' the magnet almost instantaneously, but you may critically damage the machine (and it can cost $100,000 to get it running again). There's also a 'ramp down', which often costs $20,000 - $30,000, but requires special equipment and usually needs to be scheduled a few days in advance.
The magnet is on permanently. Even if you switch the electricity off, the magnet will stay on.
Switching the magnet off, or reducing the strength, needs to be done by a service engineer, which can take hours or days to arrange.
It is possible to switch off the magnet in an emergency, but the magnet will lose the cryogenic helium. Restarting it after emergency shutdown can cost $50,000 and mean the scanner is out of commission for 1 week.
What has a metallic chair to search in this f**ing room ? There hasn't to be metallic things in anyway, it can be deadly for Patients. Stupid Guys in this Hospital
MRI Machines can be turned off, BUT YOU CAN'T TURN OFF A MAGNET. The MRI machine has a big ass magnet, they just make the magnetic feild stronger by running electricity through the coils/magnet. But when off, the magnet is not as strong but can hold onto metal objects. You should see an oxygen tank go flying into one of those things....
It's a superconducting magnet, so you can turn it off. It may not be simple to turn off (expensive, large release of energy), but yes, you can "turn off a magnet".
Its a helium cooled superconducting magnet. Turning it off is done by a process known as quenching, it involves the helium being boiled off, and that is something that will cost many thousands of pounds/dollars to put right, and would disable the machine for a few days to weeks.
In an emergency, yes switch the machine off, but in this situation just do what you need to get that chair out, and don't tell the boss!!!
fucking idiot go learn what you're trying to shit on.
you can't just fucking 'turn off' a superconductor.
as long as it is still cold it will hold a charge FOREVER. conservative estimates say a superconductor could hold it's charge until the HEAT DEATH OF THE UNIVERSE.
Forgot to mention that in this video it was a new 1.5 T magnet and the the new magnets have a reverse winding to shorten the reach of the field so many people do not realize how strong it is until its too late. Best thing you can do is stay out of the room unless you have someone trained to accompany you who knows what is okay and what isn't. I have special titanium tools that I use to service these machines. If you have a question, ask me! I'll gladly answer to stop the MRI myths that are here.
So please tell me, what happens if you are a patient, have dental fillings, and are about to be scanned? Would they be pulled out of the teeth? Would the machine break the neck by attrackting the dental fillings? Would the fillings heat up?
At work, I regularly use a soldering machine (works via electromagnetic induction) and just some days ago forgot, to remove my wedding ring. THAT HURT! :)
One of my co-workers has a metal plate in his jaw, he is not allowed to use that thing.
As far as I am aware of the metals that are used in dental filling are not ferrous materials--gold, silver, etc. I have two (small) :) fillings in my teeth and have never had a problem. Every patient is screened for potential items that could be ferrous or affected by the magnetic fields (pacemakers for example).
Quenching is very quick, heat is introduced which initiates the boil off of the helium but this is generally only used if there is human injury because there is major loss of helium. Ramping down is a bit longer, we actually attach a current probe and discharge the magnet and that usually takes 20-30 minutes or so. Helium boil off is minimized and this how some maintenance is performed.
Power on my sites is 3 phase 480 VAC and is stepped down where needed throughout the equipment.
Not often, we will ramp it down for maintenance that needs to be done without the field, most often for the cold head or for direct work on the turret.
I work on this brand of magnet, and actually have worked on the magnet shown in this video. In regard to how it is super cooled we use liquid helium but we do not use liquid nitrogen. Nitrogen was used on older technology.
Also, magnets are always "on". Even when the tech shuts down the machine at night the magnetic field is always present and cannot be removed unless it is quenched (the liquid helium is boiled off) or ramped down (the current is removed from the superconductive wiring.)
would not be clever. The MRI machine needs a lot of time to "reboot" because the magnetic field is hold up by Superconductivity (liquid helium cools down the material).
So a reboot needs a lot of time while not patient can be scanned - and that meens a huge finan
Reminds me of the house scene were a bullet gets ripped out of a guys head and ruins a 3 000 000 dorra machine lol
parth0096 2 months ago
as a patient that has to have mris regularly this is pretty scary..
blackriflex39 3 months ago
@LuisJLopez91 LOL good point.
mzrealm 4 months ago
the only reason I know this can happen is because I watch a tv show house :p
hulkthefuror 7 months ago
someone is highly fired
waitwhatwasthat 8 months ago
Interesting, I always thought that the MIR machine was an electromagnet of sorts that could be powered down when not in use. If an electric current doesn't create the field, what does?
cenzo188 9 months ago
@cenzo188 MRI machines use superconducting electromagnets. However turning them off would result in a quench of the magnat. When this happens, a particular spot is subject to rapid heating, which raises the temperature of the surrounding regions, which leads to more heating in a chain reaction and can damage the magnet (YBCO is pretty expensive :P)
Mandragara 3 months ago
im not even gonnna try to figure out how that chair got there lol
GallopingCloud 1 year ago
MRI fail
Henpups 1 year ago
i dont know what people are thinking but... gee can you turn a magnet off? cuz i cant. this is a very expensive machine. that would suck to have to ruin the magnet over a chair. thankfully this one was alright.
CrazyHorsies 1 year ago
@CrazyHorsies The power can be turned off but I think it takes quite a while for the machine to power down completely. My guess is it was off but the magnet hadn't fully discharged..If it was at fully strength I'm not sure they could've budged the chair at all Thats why you see him using a block of wood to pry it off
arohn2007 1 year ago
@arohn2007 turning the power off on the machine does NOT turn the magnet off. smart one
CrazyHorsies 1 year ago
Americans for ya!
nuttynutbeams 1 year ago
I walked in to the magnet room once and forgot that I had my cell phone in my pocket. Need I sau more? Fortunately there wasn't anyone on the magnet. My cell was dead the very next day. LoL
Takoeye2008 1 year ago
what the fuck are you doing to my MRI machine??? I am coming back you cunts!
protobuddha 1 year ago
What would happen if a an MRI machine was on, and then the power went out ? :O
seansdoesntdoweed 1 year ago
@seansdoesntdoweed It's always connected to a back up power supply. Usually an emergency generator.
Takoeye2008 1 year ago
@Takoeye2008 yeah, i thought those were just for the lights and life support. but i guess MRI's do tooooo...
seansdoesntdoweed 1 year ago
This has been flagged as spam show
@seansdoesntdoweed It's always connected to a back up power supply. Usually an emergency generator.
Takoeye2008 1 year ago
If you are about to go for an MRI scan DO NOT WATCH THIS STUFF!!!!!
It is less safe not to have it done when you may have a brain Tumor that needs treatment. I am waiting for my results from this unpleasant experience but tell you what I am so glad science gives me the option to try and get some treatment!
Don't bury your head in the sand and don't die of ignorance!!!
SojournFive 1 year ago
yeah you need to turn he helium on!
eline239 1 year ago
OMG. i have to get an MRI this week. im HORRIFIED.
moondancing08 1 year ago
@moondancing08 only one thing is certain, you will die.
bustaphatty 1 year ago
In Obamist USA, the chair sits on you!
Junije1 1 year ago
yeah chuck norris can get off a chair from MRI with ;) just 1 hand
Matjes22 1 year ago 2
@Matjes22 Thats horrible
mhilla02 1 year ago
@mhilla02
ofcourse its horroble u cant switch of such a magnet and such a machine is importend needed in a hospital even the danger of the chair for the ppl then it flys again in machine ... but the got him out without someone gets hurt
Matjes22 1 year ago
lol wtf, what hapens if you sitting on it? "wow, why i'm Flying? FLATSCH! :D
RCPhilN 1 year ago
why would these assholes put a fucking chair in a MRI
and say yaaaaaa!!! after taking out?
MrPhilFan 1 year ago
@MrPhilFan I'm guessing someone let the chair get too close by accident and it got caught.
azurelunatic 1 year ago
god was this filmed in south texas? u should of just called chuck norris.
xSlapshot49x 1 year ago
BUT I NEED TO SIT DOWN NOW!
Ironside451 1 year ago
lol why is therea chair
KARLCIESLAK 1 year ago
Im going for an MRI on 28th April and im well scared :((!!!!
Help
XXbabyangleXX 1 year ago
@XXbabyangleXX There's almost zero risks. Apart from anxiety and claustrophobia.
conquerorqueen 1 year ago
sounds like some redneck hicks...
sasoon 1 year ago
It's like the Swan Hatch in LOST.
BundelSkipBedrog 1 year ago
that happened at the hospital i worked at except is was a vacuum(sp?) anywhoo yeah crazzzy....took 12 men to pry the damn thing off....
SarahLovesKyle101 2 years ago
its not good to do that with large objects as it could bend properties of the magnet while pulling and distort future images.. but i undertand why some engineers would do this.
minusp 2 years ago
Whose the idiot that brought in a chair!!!! It does cost thousands to shut down the unit!
chelle4966 2 years ago
They can't turn off the MRI, some of then cant be turned off
lukirossi 2 years ago
@lukirossi
quench the helium, that will do it
XV24 2 years ago
crap, i thought that for 1 time i was right¬¬ XD anyways, i got the info from wikipedia
lukirossi 2 years ago
that particular one can be turned off and on, but it takes time and money to do that. The way they did it is not the right way to do it, ramping the magnet down and then up again would be the best way.
minusp 2 years ago
lol 0:24 the camera has trouble as the magnetic feild changes.
iminyourbasement 2 years ago
i would laugh at wolverine if he ever went in one hahahaha
willdick999999 2 years ago 3
Turn off the MRI first! hahah...
WyldeRadio 2 years ago
cool!!like pulling a floating chair on an open space xD
ragnarokrock 2 years ago
If you think that this sort of thing is a 'once in a lifetime' sort of fluke, google the following phrase
officer mri pulls gun
and see what comes up.
Mednovotob 2 years ago
Why don't turn off the machine?
AarClay 2 years ago
Because it would cost over $100,000 to quench the magnet and repower it back up not to mention the days of down time where the machine can make $3,000 per hour.
LukeL007 2 years ago 3
So basically it is expensive because of potential loss from waiting to energise ?
zekonja24 2 years ago
It is expensive because the magnet is a supercooled magnet that is soaking in liquid helium which is very expensive. It works by soaking the magnet in the helium then passing a current through it, then you turn the electirity off and due to the magnet being near absolute 0 the current stays in place, but once it heats up a little bit the helium boils off and the magnet shuts down. It costs 1000s to refill the chamber with helium.
LukeL007 2 years ago
@LukeL007 Actually you cannott repower an MRI after it is quenched. It needs to be replaced and it is dangerous and a ton of helium which is already limited will be wasted. You may be thinking about ramping the machine down.
BUtiful5edu 1 month ago
you can turn it also off but there it is also the same...cause it has an permanent magnet on it
XOROHN 2 years ago
No, it's an electro magnet - and that is definitly not permanent. But it is quite expensive to remagnetise the electro magnet after it has been demagnetised.
jonasalexanderlarsen 2 years ago
Wouldn't they just have to turn the power back on to remagnetize it?
Envergure 2 years ago 2
It doesn't work that way, look up supercooled magnets to see why. A MRI is one giant magnet and a couple of smaller magnets. The giant magnet is a supercooled magnet that requires no constant stream of electricity, as long as the temp is near absolute 0 which is expensive to maintain.
LukeL007 2 years ago
Thnx for explanation :)
zekonja24 2 years ago
@ Envergure.. they could have ramped the magnet down and then ramp it back up, this would only have lost them a small percent of the helium, however i imagine they did that to get the customer back up and running as the tooling needed to take the current out of the magnet safely is very heavy and takes time to get to site. If the magnet heated up and quenched (where the liquid helium turns to gas and leaves the magnet) it could then be re-filled and re-powered but very expensive process.
minusp 2 years ago
because it costs thousands of dollars
kutnerkal 2 years ago
Idiotas.
fromanny 2 years ago
IRONY STRIKES
TheCelticNinja 2 years ago
wow, do you speak spanish?
somacoyote 2 years ago
I'm a polyglot :D
fromanny 2 years ago
lol reminds me of when my Mom forgot to take her hair clip out when I had an MRI, she kept feeling this painfull tug on the back of her head and when she realised it was the clip and took it out it went flying into the MRI right near my arm, she grabbed it real quick but still we heard the tech guy say ' I saw that' then laugh lol ahh memories from the MRI
sionsidhe9 2 years ago 3
Ok, now I see that there are a lot of Dr Houses here :))
Go easy on the explanations dudes and ladies, not every body are scholars like yourselves.
No disrespect.
edBOYedBOY 2 years ago
lololl dr houses
lild3siiladii3 2 years ago
LOL so stupid. Um lets just uh turn it off ok. Oh i didn't think of that.
aserath01 2 years ago
No, the only stupid thing is you suggesting they turn off a permanent magnet... Can't do that.
scythelord 2 years ago
the only way to "stop" the magnet is to quench it and it cost 60 000$ to replace the gaz inside
lunaticcalm29 2 years ago
I have to wonder why, WHY no one thought of turning off the power switch?
jupy921 2 years ago
Contrary to what some films that feature MRI scanners seem to portray, they're not electromagnets that can be turned on or off. It's super conducting and essentially permanent. To switch it off you'd need to quench it, which can permanently damage the magnet so isn't advisable. (also see Mednovotob's comments below)
armondikov 2 years ago 27
Probably because that's how people assume the MRI starts a scan and then finishes a scan...
KooKas2oo8 1 year ago
@armondikov its a superconductive magnet, I work for the company, it can be RAMPED DOWN (current taken out of the magnet with a power supply takes about 1 hr) and the magnet would not me a magnet anymore without quenching it and only boiling off about 2-4% ramped up and down (3 hrs total) .. the problem is the customer would have been unable to use the machine until they got the power supply to the site (1 day or overnight) so thats why they probably just went and pulled it out like that.
minusp 1 year ago
@armondikov they meant turn the chair off, not the MRI
roofy2k 1 year ago
@armondikov
Plus, these "closed" or so called high field MRI scanners need to be cooled permanently by liquid helium. (Approx -270 C. degrees) The helium is constantly rotating-floating in the gantry. They never turn an MR off, there is a dormant status, but the magnet is always active indeed.
VoltanIgor 1 year ago
It's a permanent magnet >_> Why doesn't anyone research anything before posting comments?
shinyedgestudios 2 years ago 15
lol...im saying
chachatww 2 years ago
this magnet is not a permanent magnet.. its a superconductive magnet.. quenching it does not permanently damage the magnet, but should only be done when its a safety issue due to the cost of getting the magnet back up and running. Liquid Helium is expensive.
minusp 2 years ago
@minusp
Awesome, like in particle accellerators? which came first?
greengrendel 1 year ago
@shinyedgestudios Because most of them are children.
globe255 1 year ago
This has been flagged as spam show
"Why doesn't anyone research anything before posting comments???"
It's the internet; 92.7% of everything that's posted on it is complete horseshit.
maigheo76 1 year ago
@shinyedgestudios
No
Its a indefinant magnet
Its prinicple relys on superconductivity of the magnet device
Driv3th3hiv3 1 year ago
@shinyedgestudios its a superconductive magnet, I work for the company, it can be RAMPED DOWN (current taken out of the magnet with a power supply takes about 1 hr) and the magnet would not me a magnet anymore without quenching it and only boiling off about 2% of the helium that is in it. then it can be ramped up again (one hr) and again lose about 2% .. the problem is the customer would have been unable to use the machine until they got the power supply to the site (1 day or overnight)
minusp 1 year ago
@shinyedgestudios It's not a permanent magnet, like the kind that you stick onto your fridge door. It is superconducting (close to a perpetual motion machine for electricity) and it does take a lot to 'turn it off', but it's not permanent.
Mednovotob 1 year ago
Comment removed
edBOYedBOY 2 years ago
If it was an ELECTRO-Magnet I did. And I know there are permanent magnets in the thing, however they have juice going to them which increases the field; just like an Electromagnet. If you were to turn off the power, the field strength would be a great deal less. Someone told me they do not shut them down due to the cost of rebooting them. I am not aware of any permanent magnets able to generate such a field without additional power and some coils in them.
jupy921 2 years ago 2
The magnets are electromagnets that are super cooled with liquid helium to make the coils super-conductive. This makes it extremely expensive to power down because of the cost of more liquid helium.
NukeMoose420 2 years ago
Imagine if you were a patient getting an MRI and there was a scalpel in the room. ._.
musubi69 2 years ago
That's why many professional and accrediting bodies have recommended using the new ferromagnetic (only) detector systems to screen everyone and everything that goes into the MRI room (to keep ferromagnetic materials out). Check out my videos, including one that features Dr. Emanuel Kanal, noted MRI safety guru.
Mednovotob 2 years ago
Omg :|
you don't to study radiography to know
you dont put metal near giant magnets
:|
stareleades 2 years ago
Gang of idiots.
Gradius0 2 years ago 2
For something like a chair, with a fair amount of ferromagnetic material. Would that cause changes to the magnetic domains on the permanent magnet, resulting in the facility having to "re-tune" the parameters for the machine? Or can the machine compensate when it shims at the start of the scan?
vix86 2 years ago
why that heck was there a metal chair in there???
aberproductions 2 years ago
make sure you dont get a MRI there ,your life is in your own hands for sure,butch of retards.
inagod 2 years ago
haha!!
aberproductions 2 years ago
Someone throw a bunch of knives into one of these.
raunchbear 2 years ago
who was stupid enough to put a metal chair in there,
inagod 3 years ago 7
That's exactly what I thought..
jeffcoat1959 2 years ago 2
Some people look at the outside of the chair and see plastic and cloth and think that that's what it must be made of. Others know that it has ferromagnetic material inside, but think that they can bring the chair 'just inside' the doorway and everything will be fine.
Neither option is smart. Better to know for sure by using one of those new ferromagnetic detectors to make certain.
Mednovotob 2 years ago 2
Its also possible they thought they'd be "ok" with the chair off to the side, since the magnet is actively shielded. The field strength only starts to ramp up (exponentially? cubically?) near the bore. Either way, someone was careless.
vix86 2 years ago
HA !!! what a magnetic field !!!
mekarer 3 years ago
Aint these video guys fools? Anit common sense dictate that the MRI machine must first be turned off (in order to eliminate its strong magnetic field) before the seat can be easily removed? Or was this a deliberate stunt to demonstrate the magnetic field power of the MRI machine?
7olusegun 3 years ago
It's not easy to turn the machine off safetly, i think it costs a lot of money to turn it on again
irenia 3 years ago
I have seen an MRI machine in a hospital and I dont think it cost anything turning on or off this machine. It is more or less like turning on/off an X-ray machine. It costs next to nothing. I think this video was a 'public' stunt to whila away stress or to demonstrate the magnetic power of the MRI. Assuming you're correct, then safety precautions (like no loose metalic objects nearby) etc were ignored and cost should be the lesser evil.
7olusegun 3 years ago
Even with it off there is still a strong field if it was on they wouldn't of been able to remove it at all.
necromx 3 years ago
I thought the powerful magnetic field of the MRI machine is electromagnetic (which disappears when it is turned off).
7olusegun 3 years ago
It sits idle but when it actually scans the field gets way stronger as others have pointed it it does cost a lot to shut down completely. Once it's running it doesn't cost as much to keep it on as the huge amount of current to get it started.
necromx 3 years ago 2
Most MRIs (certainly the one in this video) are electromagnets. But the electricity bill to run such a magnet would make an already expensive machine much more costly to operate. The fill it with liquid helium which makes the wires used for the electromagnet superconducting. The electricity goes in, and - as long as you keep it at 4 degrees Kelvin - never comes out. That's why you can't just switch it off. You have to boil the helium to get the current to go away fast.
Mednovotob 2 years ago 2
O.K. that is a reasonable explanation. But i also thought there might be an 'emergency turn off' mechanism that might help 'bleeding of' all the current (perhaps to earth) of if this aint possible, then they should simply leave the magnetized seat as it is until the magnetic field reduce enough (via incremental boiling of the helium superconductor) for it to be removed (I think).
7olusegun 2 years ago
There is an emergency button... called a 'quench button' which triggers a heating element inside the liquid helium. MRI's are like Stradivarius instruments. Think of quenching an MRI as cutting all the strings on a million-dollar cello at once with a pair of bolt-cutters. Sure, they're just the strings, but do you really want to risk doing structural damage to the instrument? Also, about waiting, MRI providers count on $1,000 / hr in revenue. Waiting is a very expensive option.
Mednovotob 2 years ago 4
I hope to god I know as much about Radiography as you
I'm applying for it this year :)
I really want to specialise in Mri already :)
stareleades 2 years ago
Just so you know, unless your in the Military you need to take a 12 month course for MRI (a stand alone school. You don't need to be RT certified for MRI. MRI pays well, but is a boring job. With a constant pinging it sounds as though you are in a sub all day long. If your considering becoming an MRI tech, ask your local hospital to sit in for a day to get a grasp on what your getting yourself into.
KBFF 2 years ago
yes it costs alot of money, more then 20000$
kjarlsn 3 years ago
You mean it cost $20000 to turn off an MRI machine?
7olusegun 3 years ago
yes, sorry
kjarlsn 3 years ago
How?
7olusegun 3 years ago
The machine uses helium to cool down the system. I that helium has to be changed if restartet. Something like that, i a m actually not 100% sure. my radiograpy teacher told me.
kjarlsn 3 years ago
Wow! if that's the case, then there must be a way of turning off the huge magnetic field of this MRI machine without turning off the machine. This MRI machine resemble the ones I see in some hospitals which are used (i.e. turned on and off) relatively frequently. I do not think $20000 is required for each turn on / off.
7olusegun 3 years ago
Only in emergency situacions. I think you have to take out the helium so the magnetic field will be eliminated immediately. something like that. if u just power it off normally i think it will take alot of time for the field to go away. Try ask at the hospital, i will do the same:)
kjarlsn 3 years ago
I think the whole confusion here is what is off. They aren't really ever off they are either idle or in use when in use there is more stuff going on and more power being used but when idle it still keeps gasses pumping and what not.
necromx 3 years ago
There are two normal ways of shutting the magnetic field off.
An emergency ramp down or quench and a standard ramp down done by service personnel with a special ramp power supply. The first way is done only when there is a patient at risk, takes a short amount of time (<1 minute) and is costly since most of the liquid helium will be lost. The second method takes an hour or so but only about 3% of the liquid helium volume will be boiled off.
dertwood1 3 years ago
The question is what does 'off' mean? The big magnet (that sucked the chair in this video) is never off. During the exam, there are other parts of the MRI (the parts that make the noise) that depend on the big magnet being on. These other parts (gradient fields and RF transmitters) can be turned off with a switch, so that the machine can't image. That, however, doesn't mean that the magnet is off. That's the confusion.
Mednovotob 2 years ago 2
Ok; in other words, the powerful magnetic field of the MRI machine would have to weaken gradually as the temperature of the superconducting helium coolant is gradually made to increase which might be a long time to occur.
7olusegun 2 years ago
Actually, no. Superconductivity of the coils dies very rapidly as the temperature rises just a few degrees. The (emergency) quench button activates a tiny heater inside the liquid helium vessel, but this small amount of heat is all that's needed to reach the tipping-point at which the helium boils and the coils stop being superconducting (which means electrical resistance, which means heat, which means more resistance and more helium boiling...).
Mednovotob 2 years ago 4
Yes but the progressive electrical resistance build up will lead to progressive current reduction and progressively weaker magnetic field until the latter is weak enough to 'release' the stuck iron seat (though we know this may cause the helium to boil more).
7olusegun 2 years ago
Insane magnetic feild
GmodMaster14 3 years ago 2
how the hell do you get a chair stuck in an MRI machine????!!!
hutchensriley 3 years ago
This comment has received too many negative votes show
its easier when u turn the MRI off first..
dumbestnameever 3 years ago
dude get a brain. yOu cant turn it off without causing a nucular asplosion unless you queanch the hydrogen
bananabuger 3 years ago 3
Yeah, why aren't you as smart as "bananabuger"? Just note his high vocabulary, "nucular?" "asplosion?" and "queanch???" wtf?? What a dumbshit, telling you to get a brain when he lacks the ability to spell simple words.
eigerbrad 3 years ago
yeah
do they even turn off mris though?
i think it takes foever to start up
because you got to pump liquid nitro into everything
bestSVMS 3 years ago
They are sort of always on but the magnetic field is stronger when its in use than sitting idle.
necromx 3 years ago
As for the cost..
The entire scanner...ready to go costs 20-50k.
As for the helium lost in a UNquench, its about $875-1250, for 250 liters being dumped out of the system. It would cost 3-4 times that in any other G8 country.
Oh, yeah, the machines leak too, so the room, if the hospital isnt profit bound, will have helium detectors in that room that will go off with a major leak...
shdwsclan2 3 years ago 2
I work at a "poor" hospital. All the sad saps in MRI have to determine a Helium leak is to listen for in increase in pitch of thier co-worker's voices! lol j/k
PapaDocN3D 3 years ago 3
good one xD
but these guys... oh my.. theyre called basics for a reason
Bloodsaberxy 2 years ago
The word quench make no sense absolutely because quench means to rapidly cool. The emergency shut off drains the coolant, thus heating the superconductor and creating resistance which makes it non magnetic. More like unquenching.
Ramping either bleeds coolant slowly to demagnetize the coil or charges the coil while adding coolant in proportion so that resistance nears 0.
shdwsclan2 3 years ago
Consider that there is no 'heating' or 'cooling', just transfer of heat energy. If you quench a piece of steel from a forge in a bucket of water, you are rapidly transferring the heat from the steel into the water. Steel cools, water heats and boils.
Mednovotob 2 years ago
couldnt they have just turned off the power to the machine or is that bad for it or something
coondogtheman1234 3 years ago
I've heard that it takes a few hours to turn the magnet's power down safely. Then again, I could be full of shit, just what I heard.
ECWNET 3 years ago
yeah im getting that here by reading the rest of ppl's comments you need to quench it down or something or it might send out an EMP pulse and kill all technology in a large radius
coondogtheman1234 3 years ago
yeah i just got one today and after hearing what its capable of i was a lil scared lol. but yeah when something goes wrong with them things it gets scary lol
gocolts1490 3 years ago
There are 3 solutions. 1st is what these guys did (not recommended). There's a quench (mentioned earlier) which 'turns off' the magnet almost instantaneously, but you may critically damage the machine (and it can cost $100,000 to get it running again). There's also a 'ramp down', which often costs $20,000 - $30,000, but requires special equipment and usually needs to be scheduled a few days in advance.
Mednovotob 3 years ago
lmao
tycoonmusicluver 3 years ago
This is what happens when you let rednecks operate the MRI machine.
OmedDC 3 years ago 4
@AK107
the magnetic field can not simply turn off ... there is still some time actively ;)
cplasa 3 years ago
lol a 1 million dollar machine !
lokilulu 3 years ago
Hospital bloopers! Yeah!
Of course, it's all fun and games until somebody flat-lines...
MastaRikta 3 years ago 2
you can't switch off an mri easily, its called quench.
bigwilli2084 3 years ago
Yes and it costs about thirty grand so this option is slightly cheaper
samosashot 3 years ago
ehm whats about switching off ????
AK107 3 years ago
WOW its like 2 strong men who holds the chair lol.
JakesterCorp 3 years ago
I handle a GE 1.5 tesla machine and to tell you the truth the magnet is REALLY strong.
chuchupogi 3 years ago 2
Hey, why not shut off the MRI first?
Bugstomper2 3 years ago
The magnet is on permanently. Even if you switch the electricity off, the magnet will stay on.
Switching the magnet off, or reducing the strength, needs to be done by a service engineer, which can take hours or days to arrange.
It is possible to switch off the magnet in an emergency, but the magnet will lose the cryogenic helium. Restarting it after emergency shutdown can cost $50,000 and mean the scanner is out of commission for 1 week.
ChumpusRex 3 years ago 8
you have to be really stupid to bring a standard chair into the magnet room... their unprofessionalism astounds me....
joeisthesecondcoming 3 years ago 4
What has a metallic chair to search in this f**ing room ? There hasn't to be metallic things in anyway, it can be deadly for Patients. Stupid Guys in this Hospital
holyvirgin88 3 years ago 3
MRI Machines can be turned off, BUT YOU CAN'T TURN OFF A MAGNET. The MRI machine has a big ass magnet, they just make the magnetic feild stronger by running electricity through the coils/magnet. But when off, the magnet is not as strong but can hold onto metal objects. You should see an oxygen tank go flying into one of those things....
WhispersOnLy 3 years ago
It's a superconducting magnet, so you can turn it off. It may not be simple to turn off (expensive, large release of energy), but yes, you can "turn off a magnet".
jigglesnap 3 years ago
MRIs are made so the magnetic field can be turned off
TheThnickaMan 3 years ago
Its a helium cooled superconducting magnet. Turning it off is done by a process known as quenching, it involves the helium being boiled off, and that is something that will cost many thousands of pounds/dollars to put right, and would disable the machine for a few days to weeks.
In an emergency, yes switch the machine off, but in this situation just do what you need to get that chair out, and don't tell the boss!!!
redmilkcrate 3 years ago 3
lol i guess
TheThnickaMan 3 years ago
Oh wow ROFL
xxOmgxItsxKaylaxx 3 years ago
Called an off switch
leetshoot 3 years ago
fucking idiot go learn what you're trying to shit on.
you can't just fucking 'turn off' a superconductor.
as long as it is still cold it will hold a charge FOREVER. conservative estimates say a superconductor could hold it's charge until the HEAT DEATH OF THE UNIVERSE.
Constantine331 3 years ago
BURGIO
boxer301977 3 years ago
Forgot to mention that in this video it was a new 1.5 T magnet and the the new magnets have a reverse winding to shorten the reach of the field so many people do not realize how strong it is until its too late. Best thing you can do is stay out of the room unless you have someone trained to accompany you who knows what is okay and what isn't. I have special titanium tools that I use to service these machines. If you have a question, ask me! I'll gladly answer to stop the MRI myths that are here.
mccusaf 3 years ago 2
So please tell me, what happens if you are a patient, have dental fillings, and are about to be scanned? Would they be pulled out of the teeth? Would the machine break the neck by attrackting the dental fillings? Would the fillings heat up?
At work, I regularly use a soldering machine (works via electromagnetic induction) and just some days ago forgot, to remove my wedding ring. THAT HURT! :)
One of my co-workers has a metal plate in his jaw, he is not allowed to use that thing.
79Yamato 3 years ago
As far as I am aware of the metals that are used in dental filling are not ferrous materials--gold, silver, etc. I have two (small) :) fillings in my teeth and have never had a problem. Every patient is screened for potential items that could be ferrous or affected by the magnetic fields (pacemakers for example).
mccusaf 3 years ago
Can you "off" the magnetic field of an MRI? How long is the procedure? Is it routine maintenance to switch off the MRI for a break?
How much power does it consume?
luvmsiahatethegov 3 years ago
Quenching is very quick, heat is introduced which initiates the boil off of the helium but this is generally only used if there is human injury because there is major loss of helium. Ramping down is a bit longer, we actually attach a current probe and discharge the magnet and that usually takes 20-30 minutes or so. Helium boil off is minimized and this how some maintenance is performed.
Power on my sites is 3 phase 480 VAC and is stepped down where needed throughout the equipment.
mccusaf 3 years ago
How often is an MRI discharged and why should it be discharged besides for mishaps and emergencies?
luvmsiahatethegov 3 years ago
Not often, we will ramp it down for maintenance that needs to be done without the field, most often for the cold head or for direct work on the turret.
mccusaf 3 years ago
Burgio
boxer301977 2 years ago
I work on this brand of magnet, and actually have worked on the magnet shown in this video. In regard to how it is super cooled we use liquid helium but we do not use liquid nitrogen. Nitrogen was used on older technology.
Also, magnets are always "on". Even when the tech shuts down the machine at night the magnetic field is always present and cannot be removed unless it is quenched (the liquid helium is boiled off) or ramped down (the current is removed from the superconductive wiring.)
mccusaf 3 years ago
they could have just turned it off!?
chrispalmer109 3 years ago
would not be clever. The MRI machine needs a lot of time to "reboot" because the magnetic field is hold up by Superconductivity (liquid helium cools down the material).
So a reboot needs a lot of time while not patient can be scanned - and that meens a huge finan