MRI and rings?

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Discussion

skeggysteve

Original Poster:

5,724 posts

216 months

Saturday 22nd September 2012
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Prof Prolapse said:
Pure gold is non-magnetic.

If your wife's ring was 26K you wouldn't have these issues in removing it though.
biggrin - the ring is 22k but I understand what your saying - pure gold is very soft.

Anyway an update so if anyone searches they get a full story.

Wife went for the MRI today - she had to remove her bra due to the metal fastner but when she asked about her ring they said 'of course not'.
She had a set of headphones so the staff could talked to her, she also had a hand held 'get me out of here button'.
Not a nice experience (but in no way painful, just unpleasant) but if it finds the problem then it's worth it.

mrmr96

13,736 posts

203 months

Saturday 22nd September 2012
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Gareth79 said:
The hospital don't care that you say it's non-ferrous, they just know that if you are wrong it could cause damage to their extremely expensive machine biggrin
Fairly sure you could test it using a small pocket magnet to be fair.

Can gold get a current induced in it by a magnetic field? Or does that only work for ferrous metals too?

Halb

53,012 posts

182 months

Sunday 23rd September 2012
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I know the issue has passed. But couldn't she have held her arm above her head for 10 minutes or so and then used grease to remove the ring?

mrmr96

13,736 posts

203 months

Sunday 23rd September 2012
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Prof Prolapse said:
Pure gold is non-magnetic.

If your wife's ring was 26K you wouldn't have these issues in removing it though.
I think you mean 24K.

Flibble

6,470 posts

180 months

Sunday 23rd September 2012
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mrmr96 said:
Can gold get a current induced in it by a magnetic field? Or does that only work for ferrous metals too?
Works for any metal, though there's a greater effect in ferromagnetic metals. I don't know if you'd get enough heating from the induced current for it to be a problem.

Prof Prolapse

16,160 posts

189 months

Monday 24th September 2012
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mrmr96 said:
I think you mean 24K.
I think so too.

skeggysteve

Original Poster:

5,724 posts

216 months

Monday 24th September 2012
quotequote all
Flibble said:
mrmr96 said:
Can gold get a current induced in it by a magnetic field? Or does that only work for ferrous metals too?
Works for any metal, though there's a greater effect in ferromagnetic metals. I don't know if you'd get enough heating from the induced current for it to be a problem.
The senior radiographer that told us that they would never ask for wedding rings to be removed also said that the MRI could heat the ring but the length of time a person would be in the scanner it wouldn't be a problem.

Prof Prolapse

16,160 posts

189 months

Monday 24th September 2012
quotequote all
skeggysteve said:
The senior radiographer that told us that they would never ask for wedding rings to be removed also said that the MRI could heat the ring but the length of time a person would be in the scanner it wouldn't be a problem.
Radiographers told us it just heats stuff and can trash the machine mostly.

Interestingly they were studying the effects on the obese when I stopped working at the research institute, apparently it warms their fat up biggrin.

davhill

5,263 posts

183 months

Sunday 14th October 2012
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I used to take pics near an MRI machine, when I worked as an imaging tech at Manchester Uni Medical School. I took a reading using my exposure meter, and felt the meter being tugged inexorably toward the machine. Result, one perfectly happy Picker International MRI scanner and a totally fked Weston Master V. I used longer lenses after that!

As an aside, I can't have an MRI now, having an implanted spinal cord stimulator. The machine's instructions warn of heating up, shorting out, sparking and even de-implantation - of the £16K implant. I expect that would smart...

Scans, if any, will have to be CT - or good old X-ray.

hidetheelephants

23,753 posts

192 months

Sunday 14th October 2012
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davhill said:
As an aside, I can't have an MRI now, having an implanted spinal cord stimulator. The machine's instructions warn of heating up, shorting out, sparking and even de-implantation - of the £16K implant. I expect that would smart...
That ranks along side 'terminate with extreme prejudice' as a ridiculous bit of newspeak; presumably they think people are less perturbed by 'de-implantation' than 'it rips the implant out of your body'?

davhill

5,263 posts

183 months

Sunday 14th October 2012
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hidetheelephants said:
That ranks along side 'terminate with extreme prejudice' as a ridiculous bit of newspeak; presumably they think people are less perturbed by 'de-implantation' than 'it rips the implant out of your body'?
The device is American-made!

zeduffman

4,054 posts

150 months

Sunday 14th October 2012
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Radiographer here. The problem isn't just whether a metal is magnetic or not. Anything that forms a ring, especially metal, but also parts of the body with a small contact point, will generate heat when placed in an MRI scanner. If you're in a scanner and your calves are touching at a single small point, you can (potentially, on occasion) get skin burns.

Metal can also reduce image quality so it isn't ideal in that respect either.

MRI radiographers have to be pretty strict as there are severe consequences if something goes wrong. e.g. patient has an episode whilst in the scanner and needs oxygen. Nurse runs in behind the radiographer's back with an oxygen cylinder and what happens next? Cylinder fires towards the scanner at 40mph for a 1.5T scanner (80mph for a 3T) and rattles around inside while the patient is lying inside. It's happened with babies before now and it isn't a mistake anyone wants to make. The risk is considered so high that MRI radiographers are supposed to work in pairs at all times.

Forgive them for being a little arsey sometimes, they do it for your own good wink


Edited by zeduffman on Sunday 14th October 17:19

vescaegg

25,489 posts

166 months

Sunday 14th October 2012
quotequote all
zeduffman said:
Radiographer here. The problem isn't just whether a metal is magnetic or not. Anything that forms a ring, especially metal, but also parts of the body with a small contact point, will generate heat when placed in an MRI scanner. If you're in a scanner and your calves are touching at a single small point, you can (potentially, on occasion) get skin burns.

Metal can also reduce image quality so it isn't ideal in that respect either.

MRI radiographers have to be pretty strict as there are severe consequences if something goes wrong. e.g. patient has an episode whilst in the scanner and needs oxygen. Nurse runs in behind the radiographer's back with an oxygen cylinder and what happens next? Cylinder fires towards the scanner at 40mph for a 1.5T scanner (80mph for a 3T) and rattles around inside while the patient is lying inside. It's happened with babies before now and it isn't a mistake anyone wants to make. The risk is considered so high that MRI radiographers are supposed to work in pairs at all times.

Forgive them for being a little arsey sometimes, they do it for your own good wink


Edited by zeduffman on Sunday 14th October 17:19
yikes

I'd get that ring removed OP....