[chris (OP)]

I had an MRI scan yesterday (hopefully for nothing serious), but while I was laying in the tube for half an hour, listening to the banging and knocking noises going on around me, I became aware that my gold wedding ring was "buzzing"; it was a strange sensation as though it were vibrating extremely rapidly.

Could the radio frequencies being used to knock my hydrogen atoms of kilter also have been picked up by the ring and induced some sort of magnetic eddies that were interacting with the magnet to produce the movement I could feel? Or was this all my imagination?

[Probably one for @alancalverd this!]

[chiralSPO]

Well, at the risk that someone more knowledgeable might contradict me...

I believe it is entirely possible that a conductor (like a gold ring) inside an MRI cavity would interact with the changing magnetic field (Lenz's law). I suppose this could feel like "buzzing" if the frequency and amplitude were just right. I'm surprised you were allowed to keep the ring on. When I had an MRI they were very insistent that I remove anything remotely metallic, including my ring. Supposedly some tattoos contain dyes that interact with the magnetic field of an MRI, causing local heating and significant discomfort.

[chris (OP)]

Supposedly some tattoos contain dyes that interact with the magnetic field of an MRI, causing local heating and significant discomfort.

Yes, they asked me about tattoos - of which I have none! - but were not unhappy about my ring.

I think the magnetic field inside the scanner is static and the body slice activation is achieved by radio frequency pulse. This is why I'm speculating that the ring was acting as an antenna and, when the RF was being applied, conveyed a chaning current that produced its own changing magnetic field which, in turn, interacted with the field and made the ring feel like it was dancing on my finger. But I'm not sufficiently up on MRI technology to know if I am talking rubbish or not!

[RD]

Gold jewelry isn't 100% Au : it's an alloy. Some gold alloys include ferromagnetic metals such as iron & nickel.

"One of the things that makes the MRI produce images is that the machine also manipulates the magnetic field, rapidly pulsing it in different directions (this is also the process that makes them quite loud). This means that any ferromagnetic object is likely to vibrate during the magnetic pulses. Different people describe this sensation differently. To some, they perceive it as vibration. Others sense it as a mild electric ‘buzz’."

https://mrimetaldetector.com/blog/2009/03/mri-and-metal/comment-page-1/#comment-92841

https://www.linkedin.com/in/TobiasGilk

[chiralSPO]

I think the magnetic field inside the scanner is static and the body slice activation is achieved by radio frequency pulse.

The RF pulse is the changing magnetic field I was referring to.

[chris (OP)]

I think the magnetic field inside the scanner is static and the body slice activation is achieved by radio frequency pulse.

The RF pulse is the changing magnetic field I was referring to.

Okay, thanks.