MVD - how can some Drs see "pressure" on the nerve while others cant?

Hello - I am totally confused by this, we all get the same tests/scans - Cat Scans, MRI without Contrast, MRI with Contrast --> how is it that MVD specialists/nuerosurgeons can see "pressure" on the nerve while the rest of the Neurosurgeons cannot?

One thing I do know, well from here anyway. (here being Brisbane Australia)

when I was first diagnosed the MRI machine was an 1.5 tesla machine and it had very poor resolution

my doctor could not see anything and my Nurologist could barly see a thing. But my Nurosurgeon could make out a blood vessle that was an issue. Plus the MRI Doctor IE the Tech that does the scan writes a report and this has info IE they see a blood vessles etc.

Now just before I went in for surgury they installed an 3 tesla machine. Much louder and more clarity

In Australia there was a scandle about a goverment incentive re MRI machichines and clinchs back dateing install dates etc.

So an 3 tesla machine has more clarity

Note the more tesla the higher the magantisim the LOUDER it is.

My last two visits have been in 3.5 tesla units .

I can make out a bloody blood vessle on a TN nerve with a 3.5 tesla machine.

Note there is a plan for a 5 and and higher tesla machine soon. Edit there is a 9.4 tesla machine that is used for medical science

The above measurements are the raw power of the units befor the Focus IE how it is applied. They dont just slam all that power into you body. but it is the field strenth of the magnet.

The strength of the signal that they beam into you for a particular test is a question for a speacalist

this is just my understanding of the raw power of the units for asking lots and lots of questions of lots and lots of people. You google and not much come up suprisingly.????

(I am a tech and we have lots of problems with radios around the MRI area in every hospital)

Not all MRI machines are created equal, as evidenced by Simon's posting. The "gold standard" for MRI investigations in TN is a FIESTA MRI with special magnet weightings to provide 0.66 mm resolution in the area of the brain stem. the procedure is performed both with and without contrast agent, and processed post-procedure for 3-D reconstruction of the image. Some MRI centers aren't equipped to perform the procedure and not all insurance companies are willing to pay for it. In both cases, they may not TELL you that they aren't fully equipped, because you would go somewhere else and take your money with you.

Regards, Red

ok thank you both, if I had to guess John Hopkins prob has decent equip, think it may be time to bite the bullet and face my fears to make this call. Not sure why I am so afraid of a potential MVD

I am planning to ask the neuro about the same thing when I see him on Thursday, I was so bleary eyed by the time I talked to him last time, I didnt hear a word he said. I will message you when I get an answer,


Well after this discussion yesterday I went and asked a few (OK a lot) of questions of some people who have some knowledge of the units in Brisbane

The unit i last went to sleep in, this time it was for my back suprisingly enough was 5 tesla. (Brand New)

The are continualy upgrading the units around here.

The useless $^%$#@@ lost about 5 years of scans about a year ago so I never let them (My Scans) out of my sight now.

But they do give the scans on DVD so I often put the scans on my computer. This is mainly so that I have copies.

But also when my Doctor friends come around they can have a look if they want.

Note I have never seen 3 - d reconstruction or FIESTA MRI used in Brisbane Australia.

I wonder if that causes issues??

Lastly The Higher the Tesla The louder the unit. I never fail to fall asleep though

Albee - I am having the MVD at Hopkins on July 31st... I am scared to death but I can only hope they find something to fix, as Dr. Lim said they don't always see everything on the MRI (although I had mine done at the Mayo in FL and apparently there IS something there). This much pain has GOT to be from SOMETHING! All the best.

hi all, thanks for the great information. i am getting ready to have an MRI exam. after reading the posts, i would like to find out how good the machine is before i spend a lot of money. my question is how to find out. Do i call the radiology department and ask a technologist? who gives out this information? my neurologist office set me up for this appointment, but it is just in the hospital where he works. I live in st. louis, missouri and there are loads of imaging facilities and hospitals here, so i have other options. if anyone has some suggestions how to find out i would appreciate it, thanks, lisa

You are not alone Albee, my Dr. did not see anything either, but I cannot deal with the medications and my husband cannot deal with me and the pain, he wants me to do the MVD, but I am afraid, although a coworker of mine had the MVD done even when the Dr. did not see it, and he looked and looked until he found "stupid-vein", not an artery, stuck to the nerve and was able to sever the vain and now she is pain free. Mind you, that was her other side, which she had done eight months after doing the right side where they did find an artery touching the nerve and separated it with the teflon pad. The more pain I get, the more I think about letting them open me up ASAP!!

Albee said:

ok thank you both, if I had to guess John Hopkins prob has decent equip, think it may be time to bite the bullet and face my fears to make this call. Not sure why I am so afraid of a potential MVD

Lbudd -- you should be able to learn what model and resolution of MRI machine is being used at the hospital center by calling the office of the Chief of Radiology and asking. As I noted earlier, the standard of care for TN examinations is o.66 mm resolution in what is called a "FIESTA" procedure, with primary focus in the brain stem region. The procedure should be done both with and without contrast agent -- and the doctor's referral should explicitly require both.

Regards and best,


Yeah definitely call to find out :) From reading this post and others, I found out about the Tesla 3 and FIESTA. It would be a shame to get a lower quality MRI that didn't give enough information :(

I'm seeing a physician's assistant at an ENT place. I just called and asked if they knew where my MRI would be and what type it was.

They were friendly and gave me the name and number of the MRI place so I called and the front desk didn't know the technical details so she put me on with a technician. The tech said they have a Tesla 3 with FIESTA capability and she said they are familiar with testing for trigeminal neuralgia :) She said the look at the brain internal auditory canal (IAC) with and without contrast.

I've never had an MRI. I'm a big technology geek, so I'm pretty excited about seeing pictures of my brain!

Johns Hopkins does the Fiesta MRI, it took about an hour, and I got to listen to my iphone tunes the whole time, they also put this helmet type thing on my head so it had mirrors on it and I could see the technicians, I am claustrophobic and had no issues being in the machine, it is closed. They only do the Fiesta on certain days, it took 3 weeks to get in for mine, so I would call soon and get consult first. All told, it was only about an hour and a half, they had to redo a few of my films because I moved thanks to my hyperactive nature!!


Albee said:

ok thank you both, if I had to guess John Hopkins prob has decent equip, think it may be time to bite the bullet and face my fears to make this call. Not sure why I am so afraid of a potential MVD