Perils of jewelry?

[pmv]

News, but not politics.

Never been clear if this sort of thing goes in P&N or OT. Maybe this one is more 'health and fitness'?

Makes me wonder if it's coincidental that one of my dental crowns came off shortly after having an MRI.

Man killed after accidentally being pulled into MRI machine

The man had walked into the room where the machine was in use

uk.news.yahoo.com

 

[[DHT]Osiris]

How hard would it be to engage a maglock on the door if the machine is in use?

 

[pmv]

How hard would it be to engage a maglock on the door if the machine is in use?

Or just a metal detector?

I really did wonder about my mouthful of fillings and crowns when I had mine done. One of them came off either in the machine or immediately afterwards and I had to get a new one done.

In fact I've seen reports that say the newer more powerful MRI machines measurably increase the release of mercury from your fillings.

The article doesn't say what exactly happened to this guy - strangled by his gold chain?

 

[Red Squirrel]

They usually have tons of warning signs about magnetism but guess it doesn't always resonate with people until they get too close.

 

[[DHT]Osiris]

Or just a metal detector?

I really did wonder about my mouthful of fillings and crowns when I had mine done. One of them came off either in the machine or immediately afterwards and I had to get a new one done.

In fact I've seen reports that say the newer more powerful MRI machines measurably increase the release of mercury from your fillings.

The article doesn't say what exactly happened to this guy - strangled by his gold chain?

Well, the metal detector would get ripped out of the floor when the MRI came on unless it was mounted specially. The article made it sound like someone meandered into the room while it was running.

Given that it said he suffered a 'medical event' and was unable to be saved despite being injured in a hospital my money's on him being pez dispenser'd by the damn thing.

 

[lxskllr]

Quick and dirty would be a double door entrance. Go through one door into the metal detector alcove, and the second door only unlocks if there's no metal.

 

[KLin]

The real life pinchers of peril.

 

[BudAshes]

20lbs chain? Wtf

 

[Brainonska511]

Well, the metal detector would get ripped out of the floor when the MRI came on unless it was mounted specially. The article made it sound like someone meandered into the room while it was running.

Given that it said he suffered a 'medical event' and was unable to be saved despite being injured in a hospital my money's on him being pez dispenser'd by the damn thing.

MRIs don't turn on and off. They are always on.

Now, some imaging places do employ metal detectors, but they may not be at the direct entrance to the magnet room - I've seen them just used to sweep patients as a check. The technicians are smart enough to not bring metal things near the magnet. Also, the field is strongest usually in the z axis of the magnet (ie, in line with the bore) and there is some shielding in the x/y dimension. As long as the detector was outside the 5 gauss line, it would be okay.

Not sure why there wasn't better access control, but there are also plenty of warnings. Hard to stop and idiot from doing idiot things.

Having worked previously with NMR spectrometers, I and everyone we worked with knew that you don't bring metal things (or credit cards) inside the 5 gauss line, unless you wanted to risk it flying out of your hand/pocket and at the magnet.

 

[[DHT]Osiris]

MRIs don't turn on and off. They are always on.

Now, some imaging places do employ metal detectors, but they may not be at the direct entrance to the magnet room - I've seen them just used to sweep patients as a check. The technicians are smart enough to not bring metal things near the magnet. Also, the field is strongest usually in the z axis of the magnet (ie, in line with the bore) and there is some shielding in the x/y dimension. As long as the detector was outside the 5 gauss line, it would be okay.

Not sure why there wasn't better access control, but there are also plenty of warnings. Hard to stop and idiot from doing idiot things.

Having worked previously with NMR spectrometers, I and everyone we worked with knew that you don't bring metal things (or credit cards) inside the 5 gauss line, unless you wanted to risk it flying out of your hand/pocket and at the magnet.

No shit, really? I always assumed they were electromagnets specifically so they would be safe outside of use. Learned something new today!

 

[Brainonska511]

No shit, really? I always assumed they were electromagnets specifically so they would be safe outside of use. Learned something new today!

They are electromagnets. They are supercooled in liquid helium to make the coil superconducting, then charged up to field with an external power supply. After they reach their rated field and are stable, the power supply is disconnected.

On a related note, it takes a lot of helium to charge a magnet, because you're first cooling it from room temp to 2-4K, then it heats up as power is added.

 

[Fenixgoon]

They usually have tons of warning signs about magnetism but guess it doesn't always resonate with people until they get too close.

I see what you did there...

 

[Greenman]

News, but not politics.

Never been clear if this sort of thing goes in P&N or OT. Maybe this one is more 'health and fitness'?

Makes me wonder if it's coincidental that one of my dental crowns came off shortly after having an MRI.

Man killed after accidentally being pulled into MRI machine

The man had walked into the room where the machine was in use

uk.news.yahoo.com

I would think the story about the fellow who didn't know his butt plug had metal in it would have been a good warning. Does anyone not know that story?

 

[lxskllr]

I guess my new plate/screws in my finger means I can't get an MRI. Otherwise, It would be interesting to see what got pulled out of my body. I'm pretty sure I'm carrying a fair amount of tiny metal fragments from mishaps over the years.

 

[Brainonska511]

I guess my new plate/screws in my finger means I can't get an MRI. Otherwise, It would be interesting to see what got pulled out of my body. I'm pretty sure I'm carrying a fair amount of tiny metal fragments from mishaps over the years.

It depends on what the plate/screws are made from. Many implants will use titanium because it isn't magnetic; however, it is good to assume that they are magnetic, just in case - just notify MRI people if you ever need one and let them adjudicate.

 

[lxskllr]

It depends on what the plate/screws are made from. Many implants will use titanium because it isn't magnetic; however, it is good to assume that they are magnetic, just in case - just notify MRI people if you ever need one and let them adjudicate.

I specifically asked about the plate, and the doctor said steel. Dunno about the pins/screws, but steel would be my guess.

 

[Fenixgoon]

I specifically asked about the plate, and the doctor said steel. Dunno about the pins/screws, but steel would be my guess.

it will be some variety of austenitic stainless steel - typically 316LVM - or otherwise something highly stable and resistant/immune to transformation during work hardening. 1000% worth checking with the MRI people though to find out if your devices will have a response (they shouldn't). there's also a book published by a guy that reviews devices for MRI heating and movement. that's like his whole business. great way for device manufacturers (i used to work for one) to ensure that their implants will not have an MRI interaction and be MRI safe

 

[BoomerD]

This thread should be about the perils of stupidity, not the perils of jewelry.

 

[Indus]

Used the MRI with family members 5 times in 5 years.

Everytime they ask about metal objects before you enter the room.

Once my mom had forgotten her hair had pins, but then I remembered and they let me go in and take them off her hair but she wasn't lying down yet, she was still in the wheelchair about 10 feet away from the MRI machine.

So yes they always tell you, there's a big sign but people just forget!

 

[Red Squirrel]

I see what you did there...

Was wondering if someone would catch that one haha.

 

[pmv]

What happens to the iron in your blood, out of interest?

 

[Brainonska511]

What happens to the iron in your blood, out of interest?

Nothing. The iron in your blood is single molecules bound to hemoglobin and won't exhibit the magnetic properties of bulk iron.

 

[pmv]

Nothing. The iron in your blood is single molecules bound to hemoglobin and won't exhibit the magnetic properties of bulk iron.

I find that reassuring to hear. Had about three head MRIs in the space of a couple of years. Still wonder about the effect on dental fillings - coincided with a lot of dental problems - one dislodged crown and fresh decay under some existing fillings.

 

[[DHT]Osiris]

I find that reassuring to hear. Had about three head MRIs in the space of a couple of years. Still wonder if about the effect on dental fillings - coincided with a lot of dental problems - one dislodged crown and fresh decay under some existing fillings.

I feel like you're underestimating the strength of MRI magnets. If those were remotely ferrous the machine would just snatch the filling and/or tooth out of your skull.

 

[pmv]

I feel like you're underestimating the strength of MRI magnets. If those were remotely ferrous the machine would just snatch the filling and/or tooth out of your skull.
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Well, there were many reports like this (albeit this apparently relates to a new generation of more powerful MRI machines)

Metal fillings 'leak mercury after scan'

A powerful type of MRI scan releases the toxin from silver-coloured amalgam fillings, a study finds.

www.bbc.co.uk

...and as I understand it, it's the mercury that gives the fillings their integrity/stability - once it all leaks out the filling tends to disintegrate.