MRI and non-ferrous metals

[Derek Smith]

I went for an MRI scan. I removed all metal objects but forgot to remove an 18 carrot ring.

During the scan I could occasionally feel what felt like my ring (no childish jokes) vibrate slightly. It went in phases.

I thought the ring might be adulterated, but I put it on a strong magnet, one from an HDD and there was no response. It would even slide off it easily and at the same rate as silver.

I know an 18c ring is not pure but there's unlikely to be any iron in a ring from a reputable dealer. They'd mix it with too much copper or silver. Even if there was some iron, it would have been attracted to the magnet.

So why did the ring react in the scanner?

[Derek Smith]

Thanks for that guys.

It gave me something to think about in the tube.

As for my hand vibrating, the slide moved back and forth a few times.

Without going into too much detail, it was a prostrate exam and my hands were in that region so I assume the force was strong with my bits, or in that general area.

You find out something new all the time.

(I discovered I suffer from a degree of claustrophobia.)

[Derek Smith]

Mr2Mike said:

Derek Smith said:

(I discovered I suffer from a degree of claustrophobia.)

You have my sympathies. I had an MRI scan for a damaged shoulder last year and not only did I discover claustrophobia, I also can't stand being too hot and MRI scanners are akin to slow cookers. My shoulder was wedged into a plastic fixture to stop it moving and it was painfully uncomfortable after 5 minutes, took a lot of will power to keep from pressing the stop button by the end!

I feel your pain. Literally so.

It was remarkable. I was 64 for my first and I had no idea I'd break out in a sweat and have to close my eyes. 35 minutes for me. The second time I asked for a fan and even then it was an effort. I could not get a thumb between my nose and the top of the machine. Just thinking about it now makes me cringe.

I've been asked a number of times why I was scared when there's no danger. I point out that I have claustrophobia, an irrational fear. They then say, 'Yes, but why have you got it.'

What's so bloody difficult to understand about the word irrational? One should be allowed to kick them.

I have annual checks on a progressive back problem, eventually to be 6 monthly, and then I had high PSA. I've going to have something stuck up my fundament with pins sticking out of it. They say they need another scan to check they are doing it in the right place. I'd be happy for them to stab me all over.

The vibrating ring (that made two) was a welcome distraction.

As you say, it takes a lot of will power not to press the bulb. That I take away from the horrid machine with a degree of satisfaction, if not pride.

[Derek Smith]

julianm said:

Thanks a lot for the explanation I think I get it! I had some background in Chemical analysis with NMR spectroscopy but I am decades out of date.
We would discuss spin spin decoupling & similar - it was interesting being on the fringe of those techniques as a lowly user. As far as I know these days you can just let the machines suck in a sample, have yourself a coffee & read out the results!
When I heard about the first MRI machines I was fascinated.
Where will the next advance leave us I wonder?

Hopefully in a wider space.

This thread's been great. Thanks, guys.