MRI Question

[Joel Goodman]

My doc tells me I need an neck MRI to diagnose some arm pain that may be starting in the neck. On the phone the MRI facility asked me if I had ever been involved with "metal grinding". Of course as a woodworker I've sharpened tools on a wheel, drilled holes in metal etc. I'm hoping to get more answers from the techs tomorrow but has anyone here been through this? Are they concerned about stuff in the eye or ? that might be pulled by the magnet. Any information would be appreciated -- this is all rather alarming!

[Dan Hintz]

Yes, they're concerned about metal, though unless you have any chunks embedded in your skin I wouldn't worry about it. Drilling a few holes or sharpening some tools is not the same as working metal all day long.

The gauss level in an MRI machine is pretty impressive, and it can rip metallic implants right out of your body.

[Jim Koepke]

Likely a routine question.

There is some very strong magnetics going on during an MRI. The hardest part is keeping still while they are making the images.

After about 60 years of age depending on how wreak-less one was during life it becomes difficult each morning to determine if you have more aches or more pains.

Though I have not suffered many broken bones other than a slight skull fracture and a smashed finger I did get in a few bad situations. They didn't mess with me much when I was young, but the seem to come back to remind me in my later years.

Good luck, hope they find something that can be remedied instead of the "well, you will just have to live with it" they found for me.

For me, taking care of how I lay when falling asleep has a lot to do with how I will feel in the morning.

I tried a chiropractor, but that taught me, "the purpose of the spine was to support the chiropractor." (That is supposedly a quote from Daniel David Palmer, the founder of chiropractic medicine.)

jtk

[Joel Goodman]

After about 60 years of age depending on how wreak-less one was during life it becomes difficult each morning to determine if you have more aches or more pains.


jtk

+1 !!!!!!!!!

[Brian Elfert]

I had an MRI about 18 months ago. About 18 months before that I got metal in the eye from grinding that was removed. They wouldn't do the MRI without xraying my eye to be sure the metal was all gone. I guess they didn't want any metal being pulled out of my eye, which is a good thing.

[paul cottingham]

I grind most of my tools, and have had 3 or 4 (probably more) MRI's on my neck and head in the past 3 years. Never had a problem beyond having to get my shunt reset. Oh, and the fact my shoulders are wider than the tube. But that's not germaine.
YMMV of course.

[Ken Fitzgerald]

Dan,

I installed and maintained 0.5 - 3.0 Tesla MRI scanners for 24 years. I have a little experience with them.

MRI scanners won't rip implants out of your body unless it was a large ferrous implant. Let's don't overstate the case and cause people unnecessary fear. You do need to be cautious, however.
The technologist who operate MR scanners actually have a reference book that states which and what type of implants and other surgical hardware can be scanned.

The most common magnetic field strength of MRI scanners is 1.5 Tesla or in another measure 15,000 gauss. Now to give you an idea of how powerful that magnet is, the earth's magnetic field strength is commonly accepted as field strength of 0.67 gauss. A disclaimer, however, physicists routinely argue this value. So the most commonly used magnetic field strength magnet is 25,000 times the earths magnetic field strength. Remember we are talking magnetic field strength...that which causes your compass needle to point to magnetic north. These MRI scanners typically are in special rooms with specially annealed steel in the walls to keep the magnetic field in the room or they are specially constructed magnets with reverse wound coil wires on the outside which keeps the magnetic field in the room.

Some MRIs are considered low field (0.2-0.5 tesla), mid-field (1.0 tesla) and others are high field, 1.5 tesla 3.0 tesla and above.

The reason they ask that question about whether you have ground steel or ferrous metals is potentially the magnet could move the metal in your eye and damage the surface of the eye in the process. Often if there is doubt, they will shoot a head x-ray prior to doing the MRI exam. If they can see the metal, they won't do the MRI. Don't be alarmed!

I have been scanned hundreds of times. There are imaging artifact problems that cannot be realized on test phantoms due to their homogeneity. Thus, to see if a problem has been resolved, a human body needs to be scanned. Often late at night it would be just myself and the radiological technologist there. So the tech scanned me. I had a piece of steel in my arm from an oil field accident. It was there for over 40 years. Only when I knew I was going to have to install and work on a 3.0 Tesla magnet did I have the steel chip removed from my arm. When working inside the bore 1.5 T magnets I could feel the small chip of steel twist and knew it should be removed before working on the 3.0 T magnet. In fact, my employer, a large manufacturer, required us to acknowledge any stainless steel in our bodies. If people had had surgery and had screws, they had to obtain a certificate from their surgeon with the type of screw and the quality of the stainless steel used. If the screw didn't meet certain specification, you weren't allowed to work on high field MRIs.

You will probably be asked if you have any implants like a pacemaker, cochlear implant and other implanted devices.

The reason they ask about pacemakers that the magnetic field is capable of resetting/erasing the cardiac pacemakers memory. I actually witnessed this once.

The reason a cochlear implant(CI) can't be scanned is because of the rare earth magnet that is part of the implant. The antenna of the CI sound processor which looks like a hearing aid has a rare earth magnet on it. The implant under the scalp has a magnet. The two magnets hold the antenna to the scalp. The sound processor takes sound, amplifies and modulates a radio signal which goes down a small cable to the antenna and is transmitted through the scalp to the implant. I can have MRI scans but ONLY if I undergo minor surgery first, the magnet is removed, the scan performed and then the magnet surgically reinstalled on the implant. I have a CI and a recent study says that I could possibly have a scan but I wear a medical alert necklace saying "Cochlear implant....No MRI....No mono-polar cautery"at my surgeons recommendation.

I won't bore you with details about what a 1.5 T magnet is capable of but....I saw a patient bed stuck to magnet.....I saw a large metal rolling tool cart being used as a anesthesia crash cart stuck to a magnet. Keep in mind, both of these items have a LOT of steel and were very close to the magnet before they were attracted and attached to it. In either case, they shouldn't have been positioned that close to the magnet but the people who were moving them, neither of which were MRI trained radiologic technologists, were either unaware or inattentive to the rules when working around such devices.

Don't be worried....answer the questions. If in doubt, the MRI technologist won't scan you.

Don Orr, a fellow Creeker, IIRC operates MRI scanners and would be more knowledgeable.

[David C. Roseman]

Dan,

I installed and maintained 0.5 - 3.0 Tesla MRI scanners for 24 years. I have a little experience with them.

MRI scanners won't rip implants out of your body unless it was a large ferrous implant. Let's don't overstate the case and cause people unnecessary fear. You do need to be cautious, however.
The technologist who operate MR scanners actually have a reference book that states which and what type of implants can be scanned.

The most common magnetic field strength of MRI scanners is 1.5 Tesla or in another measure 15,000 gauss. Now to give you an idea of how powerful that magnet is, the earth's magnetic field strength is commonly accepted as field strength of 0.67 gauss. A disclaimer, however, physicists routinely argue this value. So the most commonly used magnetic field strength magnet is 25,000 times the earths magnetic field strength. Remember we are talking magnetic field strength...that which causes your compass needle to point to magnetic north. These MRI scanners typically are in special rooms with specially annealed steel in the walls to keep the magnetic field in the room or they are specially constructed magnets with reverse wound coil wires on the outside which keeps the magnetic field in the room.

Some MRIs are considered low field (0.2-0.5 tesla), mid-field (1.0 tesla) and others are high field, 1.5 tesla 3.0 tesla and above.

The reason they ask that question about whether you have ground steel or ferrous metals is potentially the magnet could move the metal in your eye and damage the surface of the eye in the process. Often if there is doubt, they will shoot a head x-ray prior to doing the MRI exam. If they can see the metal, they won't do the MRI. Don't be alarmed!

I have been scanned hundreds of times. There are imaging artifact problems that cannot be realized on test phantoms due to their homogeneity. Thus, to see if a problem has been resolved, a human body needs to be scanned. Often late at night it would be just myself and the radiological technologist there. So the tech scanned me. I had a piece of steel in my arm from an oil field accident. It was there for over 40 years. Only when I knew I was going to have to install and work on a 3.0 Tesla magnet did I have the steel chip removed from my arm. When working inside the bore 1.5 T magnets I could feel the small chip of steel twist and knew it should be removed before working on the 3.0 T magnet. In fact, my employer, a large manufacturer, required us to acknowledge any stainless steel in our bodies. If people had had surgery and had screws, they had to obtain a certificate from their surgeon with the type of screw and the quality of the stainless steel used. If the screw didn't meet certain specification, you weren't allowed to work on high field MRIs.

You will probably be asked if you have any implants like a pacemaker, cochlear implant and other implanted devices.

The reason they ask about pacemakers that the magnetic field is capable of resetting/erasing the cardiac pacemakers memory. I actually witnessed this once.

The reason a cochlear implant(CI) can't be scanned is because of the rare earth magnet that is part of the implant. The antenna of the CI sound processor which looks like a hearing aid has a rare earth magnet on it. The implant under the scalp has a magnet. The two magnets hold the antenna to the scalp. The sound processor takes sound, amplifies and modulates a radio signal which is goes down a small cable to the antenna and transmitted through the scalp to the implant. I can have MRI scans but ONLY if I undergo minor surgery first, the magnet is removed, the scan performed and then the magnet surgically reinstalled on the implant. I have a CI and a recent study says that I could possibly have a scan but I wear a medical alert necklace saying "Cochlear implant....No MRI....No mono-polar cautery"at my surgeons recommendation.

I won't bore you with details about what a 1.5 T magnet is capable of but....I saw a patient bed stuck to magnet.....I saw a large metal rolling tool cart being used as a anesthesia crash cart stuck to a magnet. Keep in mind, both of these items have a LOT of steel and were very close to the magnet before they attached to it. In either case, they shouldn't have been positioned that close to the magnet but the people who were moving them, neither of which were MRI trained radiologic technologists, were either unaware or inattentive to the rules when working around such devices.

Don't be worried....answer the questions. If in doubt, the MRI technologist won't scan you.

Don Orr, a fellow Creeker, IIRC operates MRI scanners and would be more knowledgeable.

Holy smokes! The things I learn from the off-topic forum never cease to amaze me. Thank you, Ken!

David

[Matt Meiser]

I've done a number of projects in metal machining facilities and have had a couple MRIs. They just did an Xray each time.

[Joel Goodman]

I've done a number of projects in metal machining facilities and have had a couple MRIs. They just did an Xray each time.

That was to check for possible stuff in your eyes -- right?

[Harvey M. Taylor]

David beat me to it. Thank you for the explanation,Ken.Max

[Ty Williams]

Ken's answer is basically all you need to know, but I figure most people who are worried about medical things often like to hear multiple voices saying the same thing. My wife is a physicist that works in medical imaging research and she studied imaging modalities, including MR, at the graduate level. I'm a mechanic, which is one of the "red flag" jobs for clinical MR. So, add those two together, and I've got more experience than most with the issue you're facing. Ken's right, there's very little real risk to you at all. However, they will bend over backwards to check and double check that everything is going to be ok if they have any reason to be concerned at all. However, the bigger "risk" is that you'll start to feel something that'll freak you out, not that you'll be in danger. Metal in your body can increase in temperature or move/buzz slightly when in an MR machine. Someone who's strapped down inside a noisy machine, in an environment that's not that comfortable and is slightly unfamiliar can easily be spooked by either of these things happening long before anything dangerous goes on. With my job, their primary concern is rust and metal filings. Basically, they're worried that I could have had rust fall into my eyes or my ears or that I could have inhaled iron filings and have them lodged in my sinuses. So, every time I go to have a scan, I first get a trip to the x-ray machine. They shoot my head from multiple different angles to make sure that they can't see anything at all. If they have even the slightest doubt, they'll shoot me again. If I'm having a series of MR scans over several days, they won't let me back into the MR without first x-raying me again if I've so much as walked into the shop since the last time they x-rayed me. So far, everything has been completely uneventful for me.


Now that pales in comparison to how careful they are with people around the 11T research scanner!

[Dan Hintz]

One thing I have not been able to find... are today's X-rays sensitive enough (i.e., high definition) to recognize metal dust particles? See a small chunk of metal is a no-brainer, and I can imagine a high concentration of metal dust in one area as being visible like a clouding of the image (similar to a tumor). But a few specs of metal dust picked up while working? I didn't think the definition was nearly high enough for that...

[Matt Meiser]

That was to check for possible stuff in your eyes -- right?

Yes, that''s correct.

[Ken Fitzgerald]

Joel,

Yes, a head x-ray is what they would shoot to see if you have metal in you eyes.

[Joel Goodman]

Thanks for all the responses. At least I understand the issues now. I am going to talk to the MRI tech -- better safe than sorry!

[Ken Fitzgerald]

Joel,

There really is no reason to be concerned.

The most common problem you see is people being claustrophobic. A small number of people don't realize they are claustrophobic until they go into the bore of the magnet.

It really is not a big deal.

Just answer the questions.

[Ken Fitzgerald]

Dan,

I suspect ferrous dust particles don't have the mass or the shape to be of concern. I suspect it would be "chips" of ferrous metal that would be of more concern.

I specialized in MR and CT scanners. My coworker locally specialized in X-ray and Ct scanners. Living in a remote area, we did this so that we each gained enough experience to be proficient in our specialized areas. That being said, I can you tell that digital x-ray detectors, certainly those used on CT scanners can image a spatial resolution in the fractions of a millimeter.

[Dave Anderson NH]

About 7 years ago I had a need for an MRI of a deteriorating (arthritic) ankle. My doctor sent me for an MRI at a stand alone MRI clinic. After about 20 minutes of filling out medical history forms in great detail I finally was interviewed by a clinician. After viewing my questionaire she asked about the notation on "multiple schrapnel wounds X2". I answered and she told me that they would not and could not do the MRI. She further questioned me about whether my doctor knew about the old wounds. When I told her yes she got really huffy and all but called my doctor an idiot. The overall impression was that I was wasting their time and was somehow at fault. To say the least, it did not leave a positive impreesion with me.

[Dave Sheldrake]

The overall impression was that I was wasting their time and was somehow at fault

Ironically enough the "Freedom" she enjoys that allow her to have a huff were provided by those willing to endure schrapnel wounds or worse. I have zero patience for those that don't show Veterans the respect they have rightfully earned and deserve!

<fuming>

cheers

Dave

[Joel Goodman]

The overall impression was that I was wasting their time and was somehow at fault. To say the least, it did not leave a positive impreesion with me.

I also feel a bit like I'm a pain in the XXX for the MRI center as I'm not answering the questions in a way that speeds the process along. I have had cataract surgery so I emailed the doc who thought an Xray of the eyes was not a bad idea. I think being a hobbyist woodworker the chances of having anything serious in my eyes is minimal -- I'll see what my regular doc thinks as my health insurance requires him to request the xray. In the old days the docs would talk to each other but there is no insurance billing code for that. Thank's everyone for all the information. It's very helpful to understand the issues and other folks experiences.

[Ken Fitzgerald]

About 7 years ago I had a need for an MRI of a deteriorating (arthritic) ankle. My doctor sent me for an MRI at a stand alone MRI clinic. After about 20 minutes of filling out medical history forms in great detail I finally was interviewed by a clinician. After viewing my questionaire she asked about the notation on "multiple schrapnel wounds X2". I answered and she told me that they would not and could not do the MRI. She further questioned me about whether my doctor knew about the old wounds. When I told her yes she got really huffy and all but called my doctor an idiot. The overall impression was that I was wasting their time and was somehow at fault. To say the least, it did not leave a positive impreesion with me.

Dave,

I suspect you saw a technologist and frankly it would very unprofessional of her to talk like that about colleague or a doctor. Even if you saw a doctor, it would be very unprofessional of her to comment in that manner about a colleague.

Yet, anybody can have a bad day and all professions have a few abrasive personalities functioning there.

[Ken Fitzgerald]

Joel,

One of the forms you sign when you go for an exam or treatment is HIPPA form. HIPPA is the patient information privacy act. This is one of the reasons that doctors don't talk as much.

My sister is a nurse-practitioner who runs a clinic in eastern Kentucky. We were discussing how HIPPA affects our professions one day. She told me this. She said "Imagine I have a patient who I determine has a heart problem and I refer that patient to a cardiologist." She said she then is forced to have the patient return to the clinic and sign a HIPPA statement allowing her to call that cardiologist about his case so she can be sure that the medications she is prescribing won't affect or be affected by prescriptions the cardiologist might prescribe for that same patient.

Let's talk about how HIPPA affected my profession. Think of a single MRI image that might have an "artifact" in it. An image artifact is an anomaly that isn't a result of the patients anatomy. In other words, it's something that is out of the ordinary. It could be caused by the patient moving, moving due to the patient breathing, it could be caused by the a problem with the MRI machine, it be an incredibly large number of things causing the problem. There are incredibly detailed troubleshooting programs, and diagnostic procedures that can involve literally days of troubleshooting an image artifact. So let's say that I find the artifact on only 1 image of several hundred images in a patient series of an entire exam. Often I can upload that image to corporate headquarters. There support engineers and design engineers can view the image to provide opinions of possible causes and resolutions. Because of HIPPA, we had to create special software that would take an image, strip it of any patient information and assign it a unique ID number before I could transmit it to corporate headquarters for analysis. Every year I had to take a refresher course in how to handle patient images to meet HIPPA regulations.

Beyond that GPs, FPs, and FNPs see more patients today in a given work day than they have done in the past. There is a huge shortage of Family Practitioners or General Practitioners and thus Family Nurse Practitioners are becoming more prevalent.

[Dave Anderson NH]

Actually, I think the woman was irritated for a couple of reasons. First, I was the first appointment of the morning. Second, this was a "for profit" stand alone MRI center not affiliated with any hospital and they didn't get any billing out of me or my insurance. The woman was not an MD, but probably a technician/ admin type. Given the price of MRIs, this had the potential of making or breaking the day's profitability and I'm sure given her overall attitude set her off on the wrong foot (as it were). Some people just don't belong in public contact jobs.

[Ken Fitzgerald]

You are absolutely correct Dave! .....some people shouldn't be interfacing with the public or don't realize how their temperament can affect the public view of their employer.

[Art Mann]

I know this is way off topic but I find it very interesting that Ken used to install MRI machines. This is just one of dozens of examples of people about whom I have read on these forums that have had or do have interesting jobs other than woodworking. What a diverse and interesting community!

[Joel Goodman]

Joel,

There is a huge shortage of Family Practitioners or General Practitioners and thus Family Nurse Practitioners are becoming more prevalent.

One of the best "docs" I've dealt with is a Nurse Practitioner near our vacation house. We could use a few more like him!

[Ken Fitzgerald]

Art we are a diverse group......from all walks of life........from a machinist who worked on rockets until he retired.....engineers.....lawyers.....doctors..... ...skilled laborers.....incredibly talent craftsman like Richard Wolfe, true artists..... and others too numerous to mention and my apologies I don't mean to slight anybody, any occupation, any profession...

We come together to civilly share information though we are all woodworkers at all different levels.

[Ken Fitzgerald]

One of the best "docs" I've dealt with is a Nurse Practitioner near our vacation house. We could use a few more like him!

Joel,

I worked with radiologists and surgeons for 34 years.

When I have a serious illness, my sister, a nurse-practitioner, is one of the first people with whom I want to talk.

[Dave Sheldrake]

I also feel a bit like I'm a pain in the XXX for the MRI center as I'm not answering the questions in a way that speeds the process along.

Look at it another way Joel, would it be right for me to get knarly with a customer of mine because they don't quite understand third point advanced nuclear physics when I ask them about the job they are wanting?

Good manners never cost anybody a penny, to me if a customer of mine is uncomfortable in any way, I have failed, if one of my staff made them uncomfortable, I have failed by not giving that staff member enough training or guidance.

If giving the customer advice or discussing their requirements takes too long to be profitable...I have failed as my figures were wrong to start with.

Customers in any job are not always right, sometimes a little bit of assistance or guidance goes a long way never forgetting please and thank you never cost anybody a dime.

Ken,
Thanks for the info, I love hearing about things I have no experience of, it genuinely does brighten the day.

cheers

Dave

[Don Orr]

As Ken said I am a registered MRI technologist with 20 years experience. His explanation is excellent and very accurate. He knows WAY more about these machines than I ever will. The questions you were asked are indeed standard safety questions we ask every patient before we scan them. A simple Xray can help determine if there is a piece of metal in your eye but it cannot tell what kind of metal. There is a documented case from the early days of MRI where someone had a piece of ferromagnetic metal in his eye, was put in the scanner and lost vision in that eye. We as techs would NEVER want that to happen. We take safety very seriously. I have people give me a hard time about it all the time. A little education goes a long way to help alleviate their concerns-usually.It has come to the point where our facility requires everyone to remove any and all body piercing no matter what they are made of. We also make everyone change their clothes into someting we are absolutley certain has no metal of any kind. These days surgical implants are tested and evaluated for MRI compatibility and most come with a wallet card you can carry that will tell the tech whether it is safe or not. Most surgical implant ARE SAFE-but not all. Mostly they just cause an artifact on the image-sort of a distortion. One of the real problems is that ANY metal can be a hazard whether it is magnetic or not. All metals are conductors of electricity and heat. All metals can have an electric current induced in them when exposed to a time-varying magnetic field and can heat up significanlty. Even tattos can be and are a real problem. Actually the induced current (Faraday's Law) is precisely how MRI works. You will be placed on what is called a coil, which is really an elaborate radio antenna which picks up the signal that is induced in your body. It's a lot more complicated than that but in a nutshell while you are in the scanner you become temporarily magnetized and you become a radio receiver and a radio transmitter.

Essentially MRI is very safe and an extremely powerful diagnostic tool. There is no high energy, ionizing radiation. It is used on tiny little babies to elderly adults an even occaisionally on pregnant women . It is one of the easiest, safest, most detailed non-invasive imaging modalities currently in use. It is, however, very noisy (hearing protection is provided), extremely boring and kind of enclosed if that bothers you. There are very good open MRI's now for the claustrophobic and larger patients.

I also grind my turning tools frequently (not frequently enough but that's another whole discussion) as well as other tools, my lawnmower blades and anything else I feel like, and am in and out of the magnetic field all day every day and have never had a problem. Safety at home is a good start for safety in an MRI. I have also been scanned MANY times as I seem to be the only willing test subject whenever we are learning a new procedure or doing some testing. Easy-peasy, for me anyway. The hardest part for many people is holding still which is critical for getting clear, sharp images.

So definitely talk to the technologist who will be doing your exam and make sure thay have answered your questions thoroughly. It's our job to make sure you are safe and comfortable during your procedure. Some people even fall asleep during their scans. To me that says they are comfortable, relaxed, and safe.

I can't claim to be perfect in my interactions with patients unfortunately. I am a lot better than I used to be. Took some effort and help to get better at it.

As to the shrapnel situation-it could go either way. If it is old and has been there a long time, it is most likey so scarred in place as to not be a problem. Remember-VA hospitals have MRI's too. Recent shrapnel or an unusual location might fly a red flag where we might want to investigate further-maybe with an Xray. Not all doctors are familiar with the limitations and realities of MRI. I could tell you stories.

Bottom line is that MRI's are safe and powerful diagnostic tools-within limits. Any questions, feel free to ask. I am also registered and licensed in Xray and CAT Scan. I hope you find this helpful.

[Dave Anderson NH]

It's old stuff Don.

Dose # August 25, 1968
Dose#2 May 25, 1969

I personally don't think there is any of it left since the deep stuff was debrided and most of the shallow stuff was gravel and worked its way to the surface and I yanked it out 20-30 years ago.

[Joel Goodman]

Don,

Thanks for all the info. I checked with the eye surgeon who did my cataracts and the thought was better safe than not -- go ahead and get the Xray of the eyes -- so they docs are (I hope) getting the approval. I also have an implant tooth with I believe a titanium post or screw holding it to the bone as well as a stainless wire holding the front five teeth together (behind the teeth) as one was getting loose. Any issues with the post or wire?

[Ken Fitzgerald]

It's old stuff Don.

Dose # August 25, 1968
Dose#2 May 25, 1969

I personally don't think there is any of it left since the deep stuff was debrided and most of the shallow stuff was gravel and worked its way to the surface and I yanked it out 20-30 years ago.

Dave,

A simple x-ray would probably show if the shrapnel still exists or not.



Don,

Thanks for all the info. I checked with the eye surgeon who did my cataracts and the thought was better safe than not -- go ahead and get the Xray of the eyes -- so they docs are (I hope) getting the approval. I also have an implant tooth with I believe a titanium post or screw holding it to the bone as well as a stainless wire holding the front five teeth together (behind the teeth) as one was getting loose. Any issues with the post or wire?

Joel,

I would ask the MRI technologists at the center. They should know.

To my knowledge, titanium isn't magnetic and the small amount of stainless wire I would not expect to be a problem.

Again....ask the techs at the MRI site. They can address those questions.

[Bill Howatt]

Tomorrow was about 11 years ago - old thread.

[Rich Engelhardt]

Yeah - 11 year old thread.
My experience with MRIs is - it's really, really, really difficult to stay awake while it's going on.
Make sure you don't have any liquids for a few hours prior to having one done.
It's impossibly hard to not move when you're doing the "pee-pee dance".

[Bill Howatt]

Sorry it was my first interaction on forum. Next time ill be careful.

No harm done. You aren't the first person to do this.
I wish they would make the threads read-only after some period of time after the last post but that approach doesn't make everybody happy either.

[Stan Calow]

Likely a routine question.

After about 60 years of age depending on how wreak-less one was during life it becomes difficult each morning to determine if you have more aches or more pains.
jtk

I often wake up wondering how it was possible to hurt myself while sleeping.

[George Yetka]

I often wake up wondering how it was possible to hurt myself while sleeping.

My wife is a violent sleeper so I have caught quite a few elbows there. Ive had my 2 year old at the time daughter shove her finger so hard up my nose it bled for an hour. Ive been poked in the eye. I once had an 5 lb crystal bowl dropped on my face that split my face open pretty good. Its safer to sleep alone.

[Thomas L Carpenter]

I also didn't notice tomorrow was eleven years ago and I've been on SMC for a long time. Seems like I would notice dates but I was too busy wondering about my gold tooth and why the mercury in my amalgams didn't cause a problem for the two MRIs I've had. Claustrophobia was a far bigger concern for me at the time but drugs take care of that nicely.

[Michael Weber]

Sorry it was my first interaction on forum. Next time ill be careful.
Well, I just read the entire thread and really enjoyed it. It’s an interesting subject so kudo’s to you. I always found the noises made by the MRI machine while having one to be very entertaining.

[George Yetka]

Well, I just read the entire thread and really enjoyed it. It’s an interesting subject so kudo’s to you. I always found the noises made by the MRI machine while having one to be very entertaining.

The helium pump or the operation?

[Ken Fitzgerald]

I often wake up wondering how it was possible to hurt myself while sleeping.

A fellow Creeker, Tyler J. Howell's mother lived to be age 92 IIRC. He said her favorite saying was "Getting old ain't for sissies!"

I am finding her opinion appears to be correct. :eek:

[Jim Koepke]

A fellow Creeker, Tyler J. Howell's mother lived to be age 92 IIRC. He said her favorite saying was "Getting old ain't for sissies!"

I am finding her opinion appears to be correct. :eek:

Getting old is a b--ch! But it sure beats the alternatives.

It seems waking up in the morning some parts of me have gotten very comfortable the way they are and will put up a fight to the end if they are requested to move.

jtk

[Warren Lake]

George sounds like their is a poltergeist in your room or your family might be trying to kill you and collect the insurance.

[Ken Fitzgerald]

Getting old is a b--ch! But it sure beats the alternatives.

It seems waking up in the morning some parts of me have gotten very comfortable the way they are and will put up a fight to the end if they are requested to move.

jtk

My father died of a heart attack on the floor of an oil rig in 1972 6 weeks before his 48th birthday. I am the oldest of 6 and still had 3 siblings in HS at the time. Now in my mid-70s, I am grateful that when I wake up with arthritic pain, I am still alive.

[Mel Fulks]

I had an MRI just ,maybe two weeks ago. They were looking for bad stuff ! Why can’t people be more upbeat ? I’m old and
getting some kind of vertigo. But I would rather crawl than use a walker ! But a big go-cart would be OK.

[Bill George]

My dad died at age 63 from a stroke, his dad passed at 48 from a brain tumor I will be 81 this July… thank you Lord!
Yes I have had many MRIs.

[Ken Fitzgerald]

Well, I just read the entire thread and really enjoyed it. It’s an interesting subject so kudo’s to you. I always found the noises made by the MRI machine while having one to be very entertaining.

Michael, the sounds you hear are normally caused by the gradient coils changing the main magnetic field in a precise way.

Have you ever seen a child build something with a set of blocks? Imagine your body built out of a child's blocks. Now we'll call those individual blocks voxels. An MRI image is made by the machine causing each voxel to produce its own distinct, individual RF signal. The machine knows in 3-D from where a given RF signal with a specific frequency was produced. The human body is made up primarily water, H2O. The MRI image is made by studying the hydrogen molecules in the body.

Different pulse sequences will produce dramatically different gradient pulses/fields and thus dramatically different sounds.

[Mike Henderson]

My father died of a heart attack on the floor of an oil rig in 1972 6 weeks before his 48th birthday. I am the oldest of 6 and still had 3 siblings in HS at the time. Now in my mid-70s, I am grateful that when I wake up with arthritic pain, I am still alive.

My father also died too soon, but he smoked and didn't really take care of his health. I've survived long past his death age.

Mike

[Incidently, very good thread. I've learned a lot about an MRI.]

[Curt Harms]

My father also died too soon, but he smoked and didn't really take care of his health. I've survived long past his death age.

Mike

My mother had 4 older brothers. They all died fairly young - unfiltered Camels all day long. She lived to be 92.

[Michael Weber]

Michael, the sounds you hear are normally caused by the gradient coils changing the main magnetic field in a precise way.

Have you ever seen a child build something with a set of blocks? Imagine your body built out of a child's blocks. Now we'll call those individual blocks voxels. An MRI image is made by the machine causing each voxel to produce its own distinct, individual RF signal. The machine knows in 3-D from where a given RF signal with a specific frequency was produced. The human body is made up primarily water, H2O. The MRI image is made by studying the hydrogen molecules in the body.

Different pulse sequences will produce dramatically different gradient pulses/fields and thus dramatically different sounds.
Fascinating Ken, I had no idea and curiosity made me ask AI. This was the reply and reads like science fiction, at least to me. There are some real smart folks in this world.

“MRI, or Magnetic Resonance Imaging, utilizes powerful magnets and radio waves to generate detailed images of the body's internal structures. Here's how it works:


Alignment of Hydrogen Atoms: The patient lies within a strong magnetic field, which aligns the hydrogen atoms in their body along the magnetic field lines.

Radiofrequency Pulse: A radiofrequency pulse is then applied, causing the aligned hydrogen atoms to absorb energy and temporarily deviate from their aligned positions.

Relaxation: When the radiofrequency pulse is turned off, the hydrogen atoms gradually return to their aligned positions, releasing energy in the form of radio waves.

Signal Detection: Specialized coils detect these emitted radio waves.

Image Reconstruction: A computer processes the signals to construct detailed images of the internal structures based on the behavior of the hydrogen atoms in different tissues. “

[Ken Fitzgerald]

Michael, AI gave you the truth!

The body tissues are made up with a large amount of water (H2O). All atoms have electrons spinning around the nucleus and thus their own resultant electromagnetic field which has north and south poles. In normal living conditions those magnetic fields are unaligned and point in different directions. The main magnetic field in an MR magnet has a north and south pole. When a body is placed into it the fields of the hydrogen atoms electromagnetic field align with the main magnets field. Now imagine the electromagnetic field of each atom as a folded umbrella with a painted spot on the edge in one place, spinning on its pointed top. When the RF pulses and gradient magnetic pulses are applied to it, each umbrella (hydrogen atom) gains energy, unfolds, and those spots become synchronized. When the RF pulse is removed, the umbrella begins to fold, and spots try to become once again unsynchronized. Thus, the hydrogen atoms give off very small RF signals. The rate of the folding of the umbrella (atoms electromagnetic fields realigning with the main MRI magnets field) and the return to the spots becoming unsynchronized is dependent on the amount of hydrogen and the purity of neighboring elements around those atoms. Thus, each atom gives off 2 distinct signals which have their own time relationship with respect to the RF pulse being removed.

Remember I mentioned volume units or voxels (the kids building blocks)? Each voxel will have its own specific individual frequency bandwidth. When the MR RF receiver gets the signal given off by the atoms, the computer by analyzing the frequency of the received signal, knows where to place that signal within the scanned body.

This results in what is called T1 and T2 RF signals. These different times result in different series of scans each of which have their own particular use as they try to image a particular disease or physical abnormality.

In some ways it's really complex and in other ways it's pretty basic. Basically the MR image is made from performing an analysis of the amount of hydrogen atoms within areas of the body. It has its uses and other modalities like CT, x-ray, ultrasound and nuclear medicine have their uses.

[Patty Hann]

I also didn't notice tomorrow was eleven years ago and I've been on SMC for a long time. Seems like I would notice dates but I was too busy wondering about my gold tooth and why the mercury in my amalgams didn't cause a problem for the two MRIs I've had. Claustrophobia was a far bigger concern for me at the time but drugs take care of that nicely.
I believe the concern is with ferrous metals/alloys. Mercury is not a ferrous metal.
Interesting history of tooth fillings.... https://www.elmsleighhouse.co.uk/blog/history-of-dental-fillings

[Lee DeRaud]

My father also died too soon, but he smoked and didn't really take care of his health. I've survived long past his death age.

No one on either side of my family has ever made it to 80. I'm currently the oldest, and the number of candles required on the cake each year is making it really hard to stay optimistic.

Chronic TMB is a pretty relentless disease. :)

[George Yetka]

George sounds like their is a poltergeist in your room or your family might be trying to kill you and collect the insurance.

I dont think they want me dead just to suffer.

[Allan Dozier]

Very informative Ken. Unfortunately when I had an MRI a couple years ago when I was going through prostate cancer I didn't get asked anything about metal working. No problems so I guess I didn't have any fragments. My question is if titanium implants cause any problems? Nowadays most orthopedic hardware I'm familiar with is titanium rather than stainless steel.

[Patty Hann]

Very informative Ken. Unfortunately when I had an MRI a couple years ago when I was going through prostate cancer I didn't get asked anything about metal working. No problems so I guess I didn't have any fragments. My question is if titanium implants cause any problems? Nowadays most orthopedic hardware I'm familiar with is titanium rather than stainless steel.

If Titanium were a problem I'd have been plastered to the Simon Med 3T magnet a long time ago.
I have Titanium in my back and neck.
Titanium is a non-ferrous metal.... a magnetic field will have no effect on it.

[Warren Lake]

think its called an Orbit what they do for your eyes. have been in the tube a few times

[Ken Fitzgerald]

Very informative Ken. Unfortunately when I had an MRI a couple years ago when I was going through prostate cancer I didn't get asked anything about metal working. No problems so I guess I didn't have any fragments. My question is if titanium implants cause any problems? Nowadays most orthopedic hardware I'm familiar with is titanium rather than stainless steel.


If Titanium were a problem I'd have been plastered to the Simon Med 3T magnet a long time ago.
I have Titanium in my back and neck.
Titanium is a non-ferrous metal.... a magnetic field will have no effect on it.

Titanium is a non-ferrous metal so the magnet's magnetic field itself won't have any affect on it. The MRI RF pulses used to give energy to the hydrogen atoms could potentially warm the titanium a very little bit but I doubt it would be noticeable but could potentially affect the image quality due the RF absorption in that given area. Don Orr would be more informed about that aspect of it.

Would you believe that some tattoos due to the metals in the inks can affect image quality on an MRI image?

Some of the most difficult image quality problems to troubleshoot, have been caused by some of the strangest things. For example, I was sent to work on a mobile MRI that was having intermittent image quality problems. The cause? Turned out in the scan room, there were several burned out incandescent light bulbs that were burned out. Removing the burned out bulbs from the scan room fixed the problem. It would appear that the broken filaments in the bulb were being flexed and touching during a scan very intermittently and the resulting arc/spark caused a very small RF signal to be generated, producing an "artifact" in the images. In fact, that is how I found the cause. During a scan I happened to notice a very momentary flash of light from what was a burned out bulb. I removed the bulbs, probems resolved.

[Patty Hann]

Titanium is a non-ferrous metal so the magnet's magnetic field itself won't have any affect on it. The MRI RF pulses used to give energy to the hydrogen atoms could potentially warm the titanium a very little bit but I doubt it would be noticeable but could potentially affect the image quality due the RF absorption in that given area. Don Orr would be more informed about that aspect of it.

Would you believe that some tattoos due to the metals in the inks can affect image quality on an MRI image?

Some of the most difficult image quality problems to troubleshoot, have been caused by some of the strangest things. For example, I was sent to work on a mobile MRI that was having intermittent image quality problems. The cause? Turned out in the scan room, there were several burned out incandescent light bulbs that were burned out. Removing the burned out bulbs from the scan room fixed the problem. It would appear that the broken filaments in the bulb were being flexed and touching during a scan very intermittently and the resulting arc/spark caused a very small RF signal to be generated, producing an "artifact" in the images. In fact, that is how I found the cause. During a scan I happened to notice a very momentary flash of light from what was a burned out bulb. I removed the bulbs, probems resolved.

Tattoos include "permanent eye liner". I don't think they will do an MRI on a person's head if he/she has permanent eye liner.

[Mike Henderson]

Tattoos include "permanent eye liner". I don't think they will do an MRI on a person's head if he/she has permanent eye liner.

Here's some information about that - https://pubmed.ncbi.nlm.nih.gov/11836774/

Mike

[Patty Hann]

Here's some information about that - https://pubmed.ncbi.nlm.nih.gov/11836774/

Mike

Good info to have (not that I have any tattoos).
A few years ago I asked the tech what would happen if I had permanent eyeliner and needed an MRI on my brain.
He said they wouldn't normally do it unless I signed off pages of liability related paperwork

[Don Orr]

Wow, this an old thread that popped up again. I've been retired for over 5 years now but the basic technology hasn't changed much. I was an MRI Technologist for 25 years for a local Medical Center. Both Ken and AI are correct. Ken is an actual expert in how the machines work and has provided some fantastic real-life information. Where I worked we were not very concerned about tattoos unless they were very colorful and fairly fresh, even eyeliner. Some of the inks used for tattoos can contain metallic pigments and that is the issue. Glitter in makeup is more of a real issue and we would have them wash it off. As you know not many metals are magnetic. If they are they can be "deflected" out of their resting position and could cause a problem. Think of a steel fragment in your eye being torn out by a very powerful magnet. It actually happened in the early days of MRI and is documented in the safety literature. It's why we had to take X-rays of peoples heads if they checked "yes" to metal of any kind in their eyes on the safety questionnaire. As tattoos age the pigments break down and are removed from the body naturally. That's why colorful tattoos don't stay colorful. The biggest safety issue with metal in MRI is heating. Very few surgical implants are magnetic these days. They even have MRI safe Pacemakers now. Implanted metals absorb the RF energy and is deposited as heat, even to the extent of causing burns. The other issue is image quality. Any metal will cause severe distortion of the acquired images. It's called a "magnetic susceptibility artifact" and is harmless to the patient-except for limiting the diagnostic capabilities of the image. You should see what dental braces do to a brain/face image !

Overall MRI is an incredible diagnostic tool that uses no ionizing(harmful) radiation to produce amazing images. Some of the newer techniques are also incredibly fast. Yes, it's noisy and boring but the results can save lives, or at least tell how bad your knee really is. Nothing to be afraid of as long as you are properly screened by staff. If you suffer from claustrophobia the newer Open MRI's are much better than back in the early days.

Hope this helps.

[Ken Fitzgerald]

The helium pump or the operation?

George, I'd forgotten about the coldhead noise a patient hears. The MRI magnet is a supercooled (LHe = liquid helium), superconductive, electromagnet. Once it's ramped up to field strength, there is no power supply connected to it to keep the electromagnetic field going. LHe is very expensive and in short supply. The MRI magnets coils are inside a cryostat (vacuum bottle if you will). That cryostat is inside a 2nd cryostat. The inner cryostat contains LHe which cools the magnet's coils. The outer cryostat is cooled to slowdown the boiloff of the LHe within the inner cryostat. Think of it as a donut inside a donut. The outer cryostat is cooled by chilled compressed helium gas. The coldhead (compressor) for the gas is attached to the magnet and runs 24x7 to cool the magnet and maintain its magnetic field. When a patient is in the bore of the magnet, they can hear the pumping sound of the compressor as it cools the outer cryostat.

[Ken Fitzgerald]

Ken is an actual expert in how the machines work and has provided some fantastic real-life information.

Thank you but hardly!