I've got an MRI scan coming up in the next few weeks for my back. Had one previously about 1.5 years ago. Took about 15mins, felt a bit enclosed but nothing too bad. The machine makes a bit of a knocking / humming noise - but they give you headphones + music so all good.

I too was slightly worried as I don't do well in enclosed spaces - but it was fine.

I had one about 5 years ago, but I think it was actually a CT type scan. I still went over a machine though, and they injected some dye first. Didn't take all that long though...

Yes, had one when my inner meniscus was teared apart in my left knee.

The hollow tube in which you go is narrow. You can listen to music, provided by a headphone not connected by a wire, but a hollow tube/. Ha! This way no metal is near the magnetic fields.

Once laying, a breeze of air will come through it, not sure why. Maybe to give fresh air, blow sweaty air away etc...

You'll feel the energy coming from it. It is tense. You know it is not a litle piece of machinery at work, but a powerful one.

You'll be ok, lay back and relax.. sleep if you want. Think of anything except the thing it may blow up with ur head in it. http://www.discussworldissues.com/fo...ies/laugh1.gif

humming noise = magnetic field.

its aint bad at all mate, from what i remember your head just goes in and there's plenty of room, not confined at all (i hate enclosed spaces). Bit of noise, just relax for a while, close your eyes and its all over, no nastiness.

The humming noise is actually compressor driving the helium; the knocking/buzzing/clanking sound is made by electromagnets cycling on and off during the scanning process.

If anybody, who hasn't had a scan before, wants to know exactly what sounds to expect, then the following website provides a considerable overview:

https://www.ynic.york.ac.uk/information/mri/sounds

How can the headphones even work in the presence of such a powerful magnetic field? http://www.discussworldissues.com/fo...es/unsure1.gif

edit - I have never had one, this is a serious question. :)

That confused me too - but they do. I was sort of expecting the world to collapse in on itself or something, but all good [thumbup]

That is strange!

My dad had one a few years ago and he got to watch TV during it. The TV wasn't in the same room, IIRC, and the image was projected in through the use of mirrors.

Metal isn't affected by magnets much more than a blade of grass.

You're thinking of iron(Fe).

I've got metal staples down the length of my breastbone, and I'm happy to report that my MRI scan did not result in a low-budget remake of Aliens.

What do you think iron is - a plastic? Ferromagnetic materials obviously respond to the presence of the magnetic field far more than other metals do, but they all react - if not through direct motion, then certainly through induced current flows. However, metal objects implanted during surgical procedures are designed to limit the amount of induction heating generated, either via using metals with low levels of conductivity or via the use of composite materials.

Yes, but blades of grass are also affected by magnetic fields.

If the metal doesn't have iron in it, it's not something you need to worry about.

If they're connected via a hollow tube then they're not standard headphones.

Most likely they don't have speakers and the tube just funnels the sound to your ears from an external source.

So you think metals with significant amounts of copper in them are safe (and this is a rhetorical question, of course)? The two mains issues of concern with metal bodies during MRI scans are movement of the object and the heating caused due to electromagnetic induction: all metals produce both side effects but, in the case of the former, it's only ferromagnetic materials one needs to be concerned with (i.e. your point about iron) and in the case of the latter, it's only metals with high electrical conductivity that will produce eddy currents large enough to generate heat that would have a noticeable biological effect.

Blanket statements of "if it's not iron, then you don't need to worry about it" are far too simplistic.

Neeyik, you've turned into a bit of an ass since your admin days....I like it! http://www.discussworldissues.com/fo...s/excited1.gif

And Dave, if you're prone to claustrophobia or panic attacks, I would tell your doctor/physician and they might be able to give you a mild sedative. Some of the older MRI machines can take up to 45 minutes depending on the scan. That would drive me insane.

Thanks for all the kind words guys.[thumbup]

I've got a bunch of Titanium up and down my back, and it's not affected in a dangerous way but I swear I can feel the titanium vibrate(probably for the reason's you cite above) It's pretty freaky feeling. The MRI techs think I'm crazy when i mention it.

That said, they do ask you up and down whether you have any metal in your body (surgical screws, staples, pacemakers, ect..) I've been told any type of modern medical procedures that require screws, ect... they use non-magnetic metals (like Titanium) so as to not interfere w/ MRI procedures. I'm pretty sure though, certain types of metals from older procedures can dislodge and really cause some problems.

I'm honestly not trying to be an ass http://www.discussworldissues.com/fo...ies/blush1.gif, but as some non-ferrous metals do provoke a noticeable reaction inside MRI scanners, I just don't think it's sensible to just say something along the lines of "if it's not iron, you're okay."

I can't claim to be an expert in this medical physics but titanium does generate small eddy currents in the presence of an oscillating magnetic field (that metal is chosen in surgical procedures because it's overall response to such fields is relatively limited, compared to other metals). It's possible that you really are feeling the titanium react to the field, given the metal's location in your body; however, it's also possible that you're your feeling something else and because of what you've been told about MRI scanners, your mind is focusing on the sensations and associating it with the scanner.

I know the tech side of things (i.e. NMR and metallurgy) fairly well but not the medical side of things - where's Gnius when you need him? http://www.discussworldissues.com/fo...ies/smile1.gif

last time I had an MRI both my glass eyes and my false teeth ended up stuck to the upper inside of the machine.

oh yeah and my foreskin piercing got attracted in the same way....... thats the last time I wear open fly boxer shorts to an MRI [no]