I had my first MRI today...
 

Sacred feces what's with the noise? Even with ear plugs that was painful. I never realized how much noise came from the magnets. Add to that the cooling fans and that was an unpleasant experience.

Finally, something on PPOT that I know a little bit about ;)

Simplifying things a bit, an MRI system has two magnets.

The big one: which causes the water molecules in your body to resonate. This is called the main magnetic field and is (very) uniform and constant.

And a smaller one which allows some regions to resonate and not others. This is called the gradient magnetic field and is switched on and off rapidly.

If the system only had a main field, all regions of your body would generate data at the same time. For an analogy think about walking into a stadium and asking, "what is your name?" and 80,000 people answered at once.

With the addition of a gradient field, most of your body is detuned and only a small volume is allowed to resonate. To extend the stadium analogy, lets say you asked "section 3, row g, seat 22 - what is your name?" and one person answered.

The noise results from these two fields interacting with each other. Generally speaking, as MRI systems become more sophisticated, they make more noise and at a higher frequency.

As an aside, the signal emitted from your body is tiny, much like one voice in an 80,000 seat stadium

I had one a few weeks ago. Yes loud for sure. Old ones are even louder.

Wait until they're in the tube for a couple hours, get the contrast. Fun ole time

Hmm. They put headphones on me and asked me what kind of music I liked. I could hear the noise, but it sounded distant, like it was coming from another room.

I've had quite a few. The old ones were very small/tight, but it never bothered me.

My last MRI on my shoulder almost sent me into a panic. I’ve had three prior and never any issues. I believe it is the result on trying to be perfectly still and not taking any deep breaths. For me it was a test of self control and calming myself down.

It was an early application of noise cancelling headphones.

Love the technology and what it can do. However I found I have claustrophobia after being in the tube for about 5 minutes. I asked to be removed as I was not in a happy place and needed to get out. Nothing happened. Took some serious and intense internal dialogs to get my mind into a space where I could tolerate the situation. 45-minutes later they pulled me out and asked if I was OK to which I replied "No'. That was met with "Are you claustrophobic?.
"Yes".
"Oh well, we just have to inject the contrast dye and you'll be done in another 20 minutes" and back in I went.

Once we were done I was trashed. It was all I could do to just get home and climb into bed. I'm hoping that I do not have to do it again any time soon.

same here... headphones and music

Gee. I can't wait.

I had one on my knee years ago. It was early in the morning so I promptly fell asleep. All I remember is her rolling me in and then telling me I can wake up, they were done.

I’ve had several on my head, which I understand doesn’t take as much time. You need to keep perfectly still and they don’t want you to fall asleep as you can twitch and then the scan isn’t as good.

Of course as soon as they roll you in, you have an overwhelming need to scratch your nose!

I had a “shock” one time as a pretty nurse rolled me in and as I got rolled out, expecting to see her again, I looked up only to see a large bearded man!

My knee was strapped in place so for that it didn't matter. Your head I can see.

Same. claustrophobia was actually a question on the pre visit questionnaire.. and I said no.. I lasted about 5 minutes before I started to panic and freak out.. The operator basically ignored my request to be removed from the machine, and told me just a few minutes more...which were unbearable...

If I ever have to have another MRI, I'm doing the open standup MRI...

It was odd discovering this fear in this fashion... I climb all over some of the tallest suspension bridges without a thought.. And braking to enter a turn at 160... bring it on..

Enclosed spaces....just no

Stood in a truck for 2 hours rubbing my 3 year old daughter's foot while she held perfectly still for a scan from her tailbone to the top of her head. She fell asleep and received no sedation. For doing so well, we were presented with a nearly $22k bill.

I've had a couple. My last one was one of the "Open" MRI's. They put headphones on me and asked me what music I wanted to listen to. Pretty sweet.

I had one last year & didn't know what to expect. When I got out, I commented it sounded like a bunch of clown in a junk yard (or something to that effect). They said nobody had ever described it like that. "aston@xxxx". That was a great description.

When I go for MRIs , the techs usually have to tell me to stay awake because I always fall asleep when it is a long scan.



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One manufacturer houses their gradient magnet in an active vacuum. It results in a very quiet exam. Highly regarded in VA’s and children’s hospitals.

Can one of you techs explain how you can have headphones (small vibrating magnets) in an MRI? Are they actually audio tubes leading to a remote speaker or something?

I've had 10. You get used to it.

Was supposed to have my 5th spinal surgery today, but it got cancelled at the last minute die to the Covid insanity.

Think string and soup cup

ge?

Here's one we installed a few years ago. Tight fit.

http://forums.pelicanparts.com/uploa...1610591682.JPG

Claustrophobic also. They put me in the infernal machine and I started to lose it. They let me out and rescheduled for the following week with heavy sedation. I made it through, but the sedation wasn't enough. Next time they either put me out or use an open MRI.

Thanks :)

I worked in the design and manufacture of MRI systems from 1982 for 20 years.

I had a bad infection in my ankle a couple months ago. They had my ankle in an MRI for at least an hour, doing all kinds of whatever scanning it does. It wasnt loud at all.

The only other time was two years ago to check for kidney stones. That wasnt fun.

you can feel the slices on your body.
very slight tingly sensation

similar to those electrical muscle stimulators at the lowest setting. very weird.. but not uncomfortable.

My main concern with MRI was the laying still.. If i'm laying that still, in an uncomfortable position, it constantly feels like I am moving.. like slight vertigo. And i try to make sure i don't move.. but it just feels weird.

afterwards they told me they could barely even see me breathe I was so still

I had one on my head not too long ago.
They didn't find anything.

Aston,

Have you heard of the gamma knife procedures? I imagine that tech is somewhat similar to MRI stuff?

My hospital room was across the hall from the gamma knife department. I rolled my wheelchair over there to ask what it was. Amazing stuff. It blows my mind that we can do things like that now.

My wish is for an imaging colonoscopy. I'll still deal with the prep in exchange for not getting poked with that camera!

Yet most extraterrestrial abductions supposedly involve an anal probe! ;)

I have had a CT scan and a MRI. They got me all strapped in and said relax and don't move around. I fell asleep waiting for them to get going, and then the table moved and woke me up. Hey, they said to relax and I did.

When I got the CT scan of my sinus area just before smart phones were released, I remember taking a seat in the patient waiting area and looking for a magazine to read. I picked up a National Geographic and it had this fantastic story of the upcoming manned missions to the moon!

I asked the nurse about the old Nat Geo and she said a family came in with their mom's collection of Nat Geo that she refused to get rid of. The nurse said the magazines go home with patients, and they did more out of the pile in the back.

With my crunched up spine and neck and now hearing loss in my right ear I have had 15 MRIs since the early 90s when they came out. With / without contrast you name it. The current generation of machines are a piece of cake. The first MRI was like slipping into a piece of 8" pipe, very very constricted. My nose was touching the ceiling and very loud. Over the years I have become claustrophobic, so I medicate with 2mg of Clonazepam, works wonders. Just had a MRI of the brain a few weeks ago. They gave me earphones and a blindfold. The blindfold really works.

I think we installed the 4th MRI in the US, decades ago. It had a bore so small it looked like it was only suited to imaging anorexic dachsunds. Lots of people simple wouldn't fit. No way I'd go anywhere near it. I pulled it out in the early 90's and sold it. Can't remember if it went for scrap or if it got sold into veterinary service.

I'd encourage anybody to check out whatever machine they may have to face, before they book the appointment. Lots of imaging centers out there, lots of choices in machines. Some are a LOT better than others.

The equipment looks somewhat similar: large box with a cylindrical bore and a patient table lined up.

But the actual process is very different.

Gamma knife "cuts" tissue using ionizing radiation, MRI images tissue using magnetic and RF fields.

Within the safety limits MRI does no detectable damage.

Funnily enough, 20 years ago I came across a virtual colonoscopy using CT data.

I thought, great they will have that perfected by the time I need it. But that hasn't happened apparently :rolleyes::confused:

4th in the US - cool! Can you remember more about it?

The small bore was required to get the magnetic and RF coils as close to the signal source as possible. Even then, it barely worked!

Subsequent development increased the dia and reduced the length.

Can't remember who made it, offhand. Cryogenic magnet, .5 tesla, I think. Field strength may have been a little less, hard to remember now.

ROLFMAO! Thanks for that.