MRI/Magnet interaction

edited May 2015 in Magnets

Yeah, so I've personally stuck my hand in an MRI without incident; however at the time I only had a V&P in that hand. Of I course I now have muliple M31s, but haven't been in the MIR room with them. I have a friend with an M31 who went into the MRI room today and states that it caused excrutiating pain. The site is also significantly swollen.

I would advise at the very least wrapping the finger or area tightly with a medical tape prior to having an MRI if possible. The bracing should be adequate to prevent any serious tissue damage. If I'm wrong... I'll let you know as soon as I get a chance.



  • Is medical tape standard procedure for this? Like, if you tell the person "I have a magnet in my finger", would they tape, or shield it or do whatever you suggested?

    Is it the kind of thing that would be torn out during a proper MRI, or just hurt really bad after?
  • If you tell the person you have metal in your body youll most likely get a ct instead.
  • edited May 2015

  • I've been shouting from the rooftops about the safety of MRIs based on this picture. How dare you question my fallacious optimism?

  • Am I the only one who wishes they could get an MRI done just to see what it's like with a magnet implant?  Even if it ripped a magnet out, I'd still be happy to have done it.

    Being that glass tags have iron components (not that I recommend it, but a neodymium magnet will stick to an implanted chip, and it did no harm to my xNT when I tried it), I wonder how they would react to an MRI, as well.  I'm imagining the writable portions of their memory could be wiped/scrambled, especially by one of the higher power MRI machines, and I suppose the surrounding tissue could be stressed, though at a lower degree than by a magnet implant that was MRI'ed.

    This has me thinking about the tattoo someone got and posted regarding magnet implants and a warning not to MRI.  I've never had a tattoo, but maybe it wouldn't hurt to get something like that tattooed on.  Something tasteful and informative.  It's been said that one is unlikely to ever be placed in an MRI machine while unconscious, but, well, just in case.  If I get MRI'ed with my implants, I want to be awake for it, damnit :)
  • Why do they ask about metal in your body before surgery? 

  • Because it's never a bad thing to have more information, and when that much is on the line you leave no variable unaccounted for. At least, that would be why I would ask about it.
  • edited September 2015
    There's an entry on the Dangerous Things FAQ about MRIs and NFC/RFID tags (no entry on magnets). It claims that the only effect is blurring on the MRI image.
  • I just finished removing my friends ntag216 before she undergoes MRI (MRT) tomorrow.
    Besides all possible issues to her body, we don't want to have the implant destroyed.
  • For those of you wondering, the reason that surgeons want to know if you have metal in your body is due to the potential for arcing when they use cauterizing equipment. This, as explained to me by my surgeon when I had my GRS performed.
  • I know that i am a bit late on this thread, but is it worth it to get the implantation's removed before an MRI and then get them replaced again? or is it just better to deal with the pain afterward.
  • Just let your medical professional know about your implant. They'll know the correct course of action, whether it be shielding, CT, or removal (although I doubt they'll straight up tell you to cut your finger open).
  • Actually, I know someone who was recently refused an MRI because of finger magnets. Strange.
  • Once removed should I wait to put it back in for a few days or is it a short enough period of time that its OK?
  • I was also recently refused an MRI because of my implants. I asked around a few hospitals and eventually found one who was willing to do it. They told it would wipe and/or disable my RFID implants. I didn't feel the RFIDs during the MRI but the magnet was somewhat unpleasant, I clenched my fist to stop it from moving. 

    The magnet was a bit tender a day or so afterward, but seems to be fine. The RFID/NFC chips were completely fine, they didn't even lose the data I had stored on them, so in this regard the MRI techs were wrong.
    If I were to have another MRI I would use sports tape to tape the magnet and hold it in place.
  • Does an MRI has any effect on the Gauss rating of a magnet? 
  • I am not able to detect any reduction in the strength of my magnet after the MRI (anecdotal). I imagine a field strong enough to degauss a magnet implant would be so strong it would not stay implanted.
  • Ya if you got in a 5-10 tesla MRI it probably would come flying out. worlds largest is 11.something if memory serves. if you were to use that as a lifter magnet you could lift a 60 ton tank off the ground. Your little magnet wouldn't stand a chance. 
  • Forget the magnet. Your poor finger would get devastated by such an encounter, along with anything else that got in the way.
  • Hello, I just wanted to share a personal experience.

    I've had an M31 implanted since last April, and I just got an MRI earlier today.  Following Cassox's suggestion in the first post, I wrapped my finger tightly in medical tape before the scan.  Tight enough that I couldn't feel the magnet vibrate at all while trying the stronger EM fields I have handy, and that part of my finger turned white (I definitely wouldn't recommend leaving it wrapped that way for long periods of time, I only had it wrapped for 30 minutes)

    The MRI machine used was a Closed-Bore at 1.5T, and I'm pretty sure the discomfort I felt in my finger was only because of how tightly I had it wrapped over that amount of time.  I didn't really feel any movement from the magnet at all during the scan.  I don't have anything to objectively measure the Gauss rating of the magnet now, but I can still use it to pick up all the metal objects I have around that it could before the MRI and it seems to feel just as sensitive now as it did yesterday.
  • Is there a list somewhere of people with magnets and their experiences with MRIs? My partner needs to get an MRI and is very nervous. What's the max Tesla rating for an MRI that's safe, etc?
  • @cassox has stuck his hand in an mri to show the safety. I believe he said he felt discomfort. Best bet is just to mention it to the person.
  • @AlexSmith do you know the gauss rating of the MRI machine they used for you?

    @cassox was the MRI on when you stuck your hand in it? What was the gauss rating?

    Sorry to bug all of you, he's just really paranoid so I'd like to get as much info as possible.
  • @cathasach depending on how many implants he has, he should be fine if wraps the area tightly tape. 

    be sure to tell the MRI tech, even thought the mag will be wrapped with tape, it may affect the image (called a starburst). also, the MRI tech can shield his hand to protect it. 

    worse case scenario is that they tell him no, he can't get an MRI and they do a CT scan instead. hell probably have some contrast fluid injected into him, it'll make him sick to his stomach for a few mins at most but then he'll be fine. CT uses radiation instead of magnetics to view the body so there's no to any of his implants if you choose that route. you may have to contact whoever your primary care provider is or whoever ordered the MRI and let them know that he has implants and would rather have CT. 

    i think he'll be fineif he wraps it in tape and has the tech shield it. 

    if he gets CT i KNOW he'll be fine. if he has a firefly, he may run into an issue with actually being able to view the image, but I'm not sure too sure, thats something for @alexsmith to answer or @cassox
  • He did have the machine on. It would have been pretty pointless to do with it off. Like jordygordy said wrap it up and tell the doc first.

    I told my doc everything about me including my implant on our first meeting.
  • if your big issue is with telling the tech about the magnet then don't worry, they will probably judge you, they are mere humans after all, however by law, no healthcare professional is allowed to share any information about your case or any identifying features about you. the most that they could say is " i had 35 year old male patient with a magnet put in his right finger" age and sex and thats it. 

    at one of the hospitals i interned at we could get into serious trouble for looking a chart of someone who wasn't under our own direct care. in california, its a felony for any person to look and disclose any personal medical information unless it becomes medically necessary. it's next to impossible for someone to share any medical information about you with out it getting into serious trouble (I.E. losing their license to practice and basically ending their career on the spot) 
  • I know this is an old post, but extra info never hurt anyone.

    I just had an MRI of my head and shoulder. The machine was a 1.5 tesla and lasted about one and a half hours. As per other information in this post i wrapped my finger tightly before going in. This did little to nothing. Although my finger was wrapped tight i should have probably made it tighter, but worried about the length of the procedure been an issue.

    There was enough pain to make me consider removing the magnet, if i need more MRIs. gripping it tightly with my other hand, did help reduce the pain. it's comparable to sticking your finger to a large neodymium magnet then pulling it off. At points the pain would decrease to the point i could nod off in the machine, or increase to the point of regretting the decision to get in at all.

    All in all it was unpleasant but bearable. The tech was more interested than anything else, to the point of reading about it while i was in the machine.

    I am not sure what the options for shielding are but i will absolutely be asking about it next time.

  • oh, additionally. No major issues after. it was tender and red for a couple of hours. no noticeable issues 24 hours later.

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