About MRI Metal Detector

Welcome to the MRI Metal Detector blog. This forum is dedicated to the improved protection of patients, staff and millions of dollars of imaging equipment through greater MRI safety, particularly via the use of specially-developed ferromagnetic detection systems.

Please hang-out, read the posts and contact us with anything additional you would like to see!

26 thoughts on “About MRI Metal Detector

  1. Robbyn

    I need help making a safety policy manual. I have a online video and the techs take a post test. I have our site zoned off as the ACR suggests.

    Any assistance would be great,

  2. Tobias Gilk Post author


    The ACR Guidance Document for Safe MR Practices: 2007, was written with the implicit intention that sites that needed safety policy manuals could appropriate some or all of the Document for their own safety policy manual. It may have elements that aren’t relevant to your site, and it may be missing a thing or two that would be appropriate to you, but it’s an excellent place to begin.

    I hope this helps,


  3. Neo

    Our facility is now OVERLY cautious about zone IV to the extent that we SHOULD wand every one going into the magnet room every time. Even when we just walked out and need to walk back in (tech ,nurse,MD etc.). I understand that we techs should be cautious which we have always been. Is this a new policy from our governing bodies (ACR, TJC etc.)? I understand to use the wand at the beginning of the case but this new rule irritates the ones I have wanded a few minutes earlier when they just have to take a close look at their patient or monitor when they have to be wanded again.

  4. Tobias Gilk Post author


    First, I think it’s laudable how seriously your site is taking MRI safety. It sounds as if they’re trying to operate with best practice standards, but that the tools that you’re using to achieve that goal make it particularly labor-intensive. I would suggest perhaps looking at pass-through or pass-by ferromagnetic detectors, so that the person can effectively re-screen (or re-verify the prior screening) themselves. Have you looked at the SAFESCAN pillar products from ETS-Lindgren (http://www.ets-lindgren.com/SafeScan)? Something like those might help you maintain the level of safety while not feeling like ‘busywork’.

    I hope this helps.

  5. Tobias Gilk Post author

    Naji, despite the name of this site, I am no longer an employee of a vendor of ferromagnetic detection systems and I can’t provide you with a quote. I recommend that you contact ETS-Lindgren. They offer the broadest range of ferromagnetic detection products of which I’m aware, and also have global sales / distribution.

    I hope this helps!

  6. Steve Geimer

    Hello Tobias,
    Thank you for providing this blog. I hope you can give some suggestion to my dilemma.
    I am a Disabled Vietnam Era Veteran. In 1996 the back injury sustained while in the service required an operation. Tripler US Army Hospital in Hawaii put screws and cages and rods in my lower back in an opertion that has held over the years. For the last two years I have been having problems related to that area where they operated. The VA farmed me out to the VA Choice Program who finally found a neurologist that accepted patients from VA Choice. That doctor wants to schedule an MRI but wants to make sure the materials in my back are MRI friendly. The VA and Tripler Hospital have not or will not provide information of what sort of materials are in my lower back. Xrays confirm all sorts of items there but not their material. I have been waiting for months. Is there a non evasive process to determine if the materials in my lower back are MRI friendly?
    Thank you.
    Hurting in Hawaii

  7. Tobias Gilk Post author

    Steve, thank you for your inquiry. I wish it was otherwise, but the short answer to your question is ‘no, there is not an FDA-approved non-invasive way to determine if the materials in your back are MRI friendly.’ (At least, not other than what you’ve already tried.)

    You could potentially find a ferromagnetic detector (used for screening patients for worn / carried / shallow ferromagnetic materials) to check yourself, but even then, that may not answer the question. Some alloys are ferromagnetic (in that they’ll alarm a sufficiently sensitive ferromagnetic detector), but exhibit such a small magnetic response that they’re of no meaningful concern from a safety standpoint. You could (potentially) wind up with a positive alarm from a ferromagnetic detector and have one of these minimally-magnetic materials.

    Ultimately, it will come down to a risk : benefit decision among you, your neurologist, and the radiologist supervising the MRI scan. The good news is that even if the materials in your back are ferromagnetic, they are anchored into bone. If you’ve had an X-ray that shows that the implants are still in place, and that the anchors still look secure, implants could exert ‘pull’ on the bones that they’re affixed to, but that doesn’t necessarily equate to injury.

    Additionally, part of the ‘benefit’ calculation will be whether or not the radiologist believes that the MRI will be able to get useful images. The presence of metal creates artifacts that can distort, or even ‘erase’ parts of an MRI image right around the metal. How bad these artifacts are depends on many things, including the type of metal (which brings us full-circle).

    I hope that this has helped, at least a little bit, and I wish you success in getting the care that you need.

  8. billy

    Hi I was recently in a MRI with supposely metal in my eye…maybe not magnetic but I was told there was 3 fragments of metal,possibly lead. Hospital knew about incident I had before the test so they took a Xray and seen nothing. Which then I had a eye appt hours after when the Dr found the “metal”. Is it possible? should I of got hurt and will there be long term damage?

  9. Tobias Gilk Post author


    If you had an eye exam shortly after the MRI exam, and the ophthalmologist did not observe any damage, then I – personally – would take that as a conclusive indication that there was no injury.

    It’s not unusual that tiny metal fragments might be missed on a pain X-ray. Some providers are using CT scans, which can be significantly more sensitive for just this reason.

    Metal fragments in the eye are generally too small to heat up to significant levels with the RF used in MRI imaging. It is a potential that ferromagnetic metals could move under the magnetic influence of the MRI scanner, and cause damage, but there is only one documented case of which I’m aware in which this has happened. In fact, a friend of mine who is an ophthalmic surgeon actually tried to force a small ferromagnetic sliver embedded in a phantom (designed to simulate a human eye) to move from an externally applied magnetic field, and he was unable to do it. To me this suggests that either the ferromagnetic object needs to be larger than that which my friend was using, or the applied magnetic field needs to be stronger than that which my friend was using.

    In my opinion, if you had an eye doctor give you a clean bill of health from that exam, you should have nothing to worry about from the MRI. I would, however, be cautious about getting another MRI while you still have those fragments in, because successful completion of one MRI does not necessarily ‘prove’ that a subsequent MRI will be safe.

    I hope this helps.

  10. terry leach

    Very interesting comments. I have a different injury that i received in the Vietnam War . I received head injuries along multiple fragments wounds all on the backside of my body. The fragments entered the skull. I also received two gunshots at the same time. One to my spine and one in my skull lower right side. This happened in 1968 (July) Though a Cad Scan they determined and can see where a bullet had entered. In 1996 I started having headache’s, just short of migraine’s . The Vet. Administration said there in nothing that they can do? Is there a means to detect what causing this? Could some the fragments shifted?

  11. Tobias Gilk Post author


    The questions you’re asking are medical ones, and not really technical. I think you’re best bet is to seek the advice of your physician. I’m sorry I can’t help you further with this. I hope your headaches can be resolved. My best to you.


  12. Marilou Festejo

    My spouse is scheduled to have an MRI of the brain & neck in 8 hours from now. Our concern is his permanentlly attached upper front dentures which his dentist say contains cobalt & chromium. I have read in this article that cobalt is tagged as a ferromagnetic metal. Should my spouse still proceed with his MRI?

  13. Tobias Gilk Post author


    I understand your concern, but in all likelihood, the presence of the metal attachment for the dental appliance is of negligible safety concern. Absolutely, make sure that he fully discloses the dentures, as well as anything else that is in or on his body that he wasn’t born with to the MRI provider, but it’s highly unlikely that they’ll have any significant safety concerns with dentures. Patients with orthodontics and dentures get MRI scans every day, and unless your husband’s work is particularly unusual or exotic, they can likely accommodate it.

    My best wishes to your husband.

  14. Patricia

    will an MRI be safe for me, as the doctor had to place staples in my right upper lobe. This was around 1985.

  15. Tobias Gilk Post author


    The best way to make this determination is to get as much information as you can get about the staples, and share this with a radiologist who can help you identify the safety / risk associated with different MRI exams.

    I hope this helps.


  16. Elizabeth

    My husband had a stapes prostheses put in somewhere between 1987 and 1990, he can’t remember when exactly, and he has no medical records from that time. There were a few stapes made during that time period that were manufactured with the incorrect metals and are contraindicated for an MRI. He needs to have an MRI, is it possible that the Ferrous detectors that are outside the Scan rooms would detect the small amount of ferrous materials before he entered the magnet room?

  17. Tobias Gilk Post author


    To the best of my knowledge, there are no ferromagnetic detectors (FMD) that have been approved for the use of finding / differentiating metals within the body. That said, if your husband was tested with one and it did alarm, I would take that alarm as a VERY strong indication that there was ferromagnetic material present. The opposite, however, I wouldn’t have equal confidence in. If tested with a FMD and there was no alarm, that wouldn’t be definitive in my mind. Stapes are very small, with a tiny mass of metal, and would be difficult to detect under the best conditions.

    In summary, if you can screen it with a FMD (I would recommend a hand-held as being more effective for this particular situation), I would take any positive alarm at face value, but would still have a healthy amount of concern for the potential that the Stapes would be ferromagnetic even if screened with no alarm.

    I hope this helps.

  18. Charles Houck

    I have 2 plates w screws in my eye socketsand there is no way to determine what the metal is made of they were put in in 1996 my dr doesnt keep records that long someone needs to make a machine to identify metal in body i i hav vertigo and they are afraid to do MRI

  19. Tobias Gilk Post author

    Dear Charles,

    If the plates are sufficiently superficial (within a cm or so of your skin) it may be possible to identify whether they are ferromagnetic through the use of a strong magnet or, even better, a hand-held ferromagnetic detector.

    Generally speaking, orthopedic repair hardware in the US is not significantly ferromagnetic, and often does not present significant risks / contraindications to many MRI exams. But this is just a generalization, and what you care about is your specific situation. For that I would advise you to speak directly with the MRI provider to get their direction on how your implant might affect their risk assessment and decision to scan.

    I hope this helps.

  20. Tabitha R Givens

    I have steel Harrington rods. They were put in in 1994. I am scheduled for an MRI of the head and neck this Thursday. Is it safe for me to have an MRI ?

  21. Tobias Gilk Post author


    Most spinal fixation devices (e.g. Harrington rods) have some MRI safety information, but may not have information for the MRI scanner type that would be used at the hospital or imaging center that you see. It would be important for you to discuss this with the supervising radiologist. Depending on the particulars of your situation, it may be entirely possible to get an MRI exam safely.

    I hope this helps.

  22. Tobias Gilk Post author


    There aren’t materials that are ‘black listed’ or prevented from being incorporated in an MR Conditional product. In its finished state, an MR Conditional device needs to demonstrate safety in three categories… Static Magnetic Field, Time-Varying Gradient Magnetic Field, and Radio Frequency Magnetic Field.

    For the static magnetic field category, an MR Conditional device needs to demonstrate that under the conditions it is designed to be used in it will not represent a risk to the patient. It would be possible to have a device made out magnets (a very significant potential projectile risk) with conditions that it needs to be kept 20-feet away from the MRI scanner. Generally speaking, however, products and devices that are made to be near the MRI, or in or on patients who are receiving MRI scans, will be made from titanium, nitinol, 316L stainless steel, polymer- or silicone-based materials, and sometimes ceramics.

    For both the time-varying gradients and RF magnetic fields, the principal concerns are related to electrical conductivity. Like with static magnetic fields, the device manufacturer can define the conditions of use, which for gradients and RF may include specific limitations on what part of the body might be scanned, or how much gradient or RF power might be used in a scan.

    I hope this helps.

  23. Monica

    I need an MRI for breast cancer. I have a stapes in my right ear, which was placed in 2001. I don’t have the model or make and the ear doctor no longer has the records. With it being such a small mass, should I be concerned? Also, is there a facility near me in southeastern Michigan where I could get it tested to see if an MRI is ok? I really appreciate this site and your information. I really need the MRI so I’m trying to figure out the best options. Thanks!

  24. Tobias Gilk Post author


    Stapes implants have different arrangements / configurations, and the positioning of the Stapes elements may need to be very precise. As a result, a small movement may make the implant ineffective, resulting in hearing loss. For this reason it is important to try and identify the ferromagnetic properties of a Stapes.

    I would suggest working with an MRI provider, ideally one that has a certified MR Safety Officer or MR Medical Director on staff, to help identify the risks and benefits of proceeding with an MRI exam.

    I hope this helps.

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