welding and MRI

[Soundguy]

Got a question. Any of you guys that have had an MRI.. I'm sure they asked you about welding right.. then if you said yes.. they did what?

A friend told me they did an 'xray' of his eyes to check for metal particles.

I figure they had to do something.. but what about the rest of your body... as much grinding and welding and messin with old tractors as many of us do.. I'm probably carrying around quite a bit of sub-dermal iron...

I know for a fact that bit of metal come to the surface on my left palm where i put a sheet metal screw thru it last year while screwing some metal tubing together...

comments?

soundguy

 

[wedge40]

I'm no doctor, and I don't even play one on TV, but my guess is they aren't as worried about small metal particles in the surface of the skin and they are in and around the eye. There may be some discomfort as the metal is pulled to the surface of the skin, but moving metal in the eye could cause blindness. Again just theory. Next time you see your doctor ask him.

Wedge
PS and then let us all know what he said.

 

[Rara Avis]

One thing, however, hasn't changed: safety. The MRI scan itself may be harmless and painless, but there are other dangers to consider. The scanner's huge magnetic pull makes even the smallest ferromagnetic object a potentially lethal high-speed projectile - as a result the MR area is carefully maintained. Patients undergo an intense screening process to ensure their well-being. Piercings must be removed before a scan, and MR staff inquires about the presence of pacemakers, cerebral aneurysm clips and any type of implants before performing a scan. They also ask patients whether they've ever worked with metal; it may seem like a tangent, but miniscule metal shards, which may go undetected for decades in someone's eye, can have disastrous effects under an MRI's magnetic pull. Even certain tattoo dyes (specifically, red dyes containing high amounts of iron) can become uncomfortably warm during an MRI.

July 2004

 

[Rara Avis]

Influence of static field on implanted metal devices or metal debris
Torsion
Ferromagnetic devices and debris will attempt to align parallel with the static magnetic field. This effect is dominant when the static field is spatially invariant. Thus, ferromagnetic vascular clamps such as those used to clamp an aneurysm might rotate slightly in the field and cause bleeding. The following example reported to the FDA illustrates the serious consequences.

MDR-349790: A patient with an implanted intracranial aneurysm clip died as a result of an attempt to scan her. The clip reportedly shifted when exposed to the magnetic field. The staff apparently had obtained information indicating that the material in this clip could be scanned safely. (11/11/92)
Torsion effects have also been used to explain the swelling and/or irritation that has been reported for subjects with tattoos and certain makeup - particularly mascara and eyeliner. The pigments in tattoos and makeup may contain iron oxides in irregular shapes that attempt to align with the magnet field and produce local tissue irritation(2000)

Translation
Ferromagnetic devices and debris within a subject�s body will be attracted to the magnet, just as would unsecured objects in the room. Thus, translation effects are similar to projectile effects described above. The following examples reported to the FDA illustrate problems associated with metal shards in the patient�s eye moving in the magnetic field and causing serious injury.

MDR-100222: Dislodgement of an iron filing in a patient's eye during MR imaging resulted in vision loss in that eye. (1/8/85)
MDR-454660: A patient complained of double vision after an MR exam. The MR exam as well as an x-ray revealed the presence of metal near the patient's eye. The patient was sedated at the time of the exam and was not able to inform anyone of this condition. (12/15/93)


Duke-UNC Brain Imaging and Analysis Center - Research

 

[Rara Avis]

Not an MRI issue...but definitely a MEDICAL ISSUE...

Mayo Clinic Case Series Illuminates Connection Between Welding, Brain Damage
Wednesday, June 08, 2005

ROCHESTER, Minn. A Mayo Clinic case series analysis has pinpointed for the first time syndromes associated with toxic damage to the brain and nervous system from manganese fumes generated during welding. The analysis also revealed that all affected patients shared a risk factor: welding with inadequate ventilation. The findings will be published online and will appear in the June 28 print issue of Neurology


Mayo Clinic - Mayo Clinic Case Series Illuminates Connection Between Welding, Brain Damage
Welding and brain damage link, Mayo Clinic

 

[Rara Avis]

A subtle demonstration of the strength of an MRI on metal in a tennis ball...

YouTube - How strong is an MRI magnet?

 

[radman1]

Got a question. Any of you guys that have had an MRI.. I'm sure they asked you about welding right.. then if you said yes.. they did what?

A friend told me they did an 'xray' of his eyes to check for metal particles.

I figure they had to do something.. but what about the rest of your body... as much grinding and welding and messin with old tractors as many of us do.. I'm probably carrying around quite a bit of sub-dermal iron...

I know for a fact that bit of metal come to the surface on my left palm where i put a sheet metal screw thru it last year while screwing some metal tubing together...

comments?
soundguy

If you tell them that you work with metal and there is a possibility of metal around the eyes, they will perform a x-ray first. This will tell them of any metal fragments. Metal fragments in other parts of the body are generally not a concern. Metal particles near the eye are a no go, although the incidence of causing a problem is quite remote. If you do have a metal fragment, say in your hand, it is possible that it could become hot or uncomfortable during the study. Won't know until you get in the scanner. If it does, the exam can be stopped but this is rare to happen. This is not a reason to not get in the scanner. Tattoos can get hot, but again rare and not a reason to not get in the scanner.

Anuerysm clips in the past 10-12 years are nearly completely safe, but few odd clips remain. MRI won't be done unless the specific clip is known. Cochlear implants or ear implants, pacemakers or infusion pumps are no go items. Any implanted wires or catheters with wires are a no go. Heart valves ok. Any hardware in bones, spine etc is ok. Penile implant - maybe ok but need to know type. Many other exceptions. You will have a nice long sheet to fill out.

 

[Skyco]

Yup- had an MRI a few years back for a neck problem. Told them I'd had a small metal fragment in one eye 30+ years ago so got the xray to confirm nothing was still there. Interestingly they weren't the least bit concerned about the two metal wire loops in my jaw bone from a broken jaw. I wondered if i'd feel anything from them but didn't.

 

[Rara Avis]

Yup- had an MRI a few years back for a neck problem. Told them I'd had a small metal fragment in one eye 30+ years ago so got the xray to confirm nothing was still there. Interestingly they weren't the least bit concerned about the two metal wire loops in my jaw bone from a broken jaw. I wondered if i'd feel anything from them but didn't.

That's because those metal loops were stainless...

 

[Danno1]

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300 series SS is not magnetic but 400 series is (to ordinary magnets). The ones used in an MRI are so strong that even the small amounts of iron in non-mag SS is enough to be attracted.

We've had those magnets at work as we make components for MRI machines. When the magnets are running they will rip a SS non-magnetic set of calipers or micometers right out of your hand and up into the bore where they will then float until the magnet is quenched. You can not pull them out, the mag field is too strong. Quenching these magnets takes awhile as does starting them back up so it was only done every few weeks. There would usually be half a toolbox up there by the time it would be quenched!

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