What if there was a Better Way to see Lesions Earlier?

[COBOB]

I buried this comment in another thread, and figured I should start a thread on it.  It seems some of us have information that our doctors may not.  It is geek stuff about MRI, but I tried to explain it in a way that didn't require a course in Tensor Calculus.

There has been a bunch of discussion about 1.5T vs. 3T MRIs here.  What if there was a way to improve the ability of 1.5T machines to image the brain and spine?  What if there was a way to see lesions developing up to TWO Years before they were visible on a T2 sequence?  Did you know that there are ways for a 1.5T MRI to see grey matter disease?  I was in Connecticut recently and was talking to some of the engineers at the Yale Magnetic Resonance Research Facility and they reminded me of some stuff I filed way years ago.

There are special imaging techniques that can show some lesions that conventional MR does not show.  The one I was most familiar with is called MT-MRI (Magnetization Transfer MR Imaging). In the MS MRI criteria, this is an option when imaging the Spinal Cord since it provides better resolution of lesions.  Rather than looking for differing proton density related to the differing amounts of water in tissue, this MT-MRI looks for the magnetic interaction between water protons and big protein molecules (like myelin) that have been activated by a radio frequency pulse.   MT MRI was an accidental discovery on a miss tuned MRI.

In terms of MS, rather than looking for more water in the myelin covering as evidence of a lesion, MT spins up the myelin, and watches where the myelin spins up the water.  It is considered one of the best techniques for finding lesions on the spinal cord because it provides better contrast between the cord and the lesion.

[Multiple Sclerosis: Magnetization Transfer MR Imaging of White Matter before Lesion Appearance on T2-weighted Images]
"The MT ratio reveals progressive focal abnormalities in MS that antedate (predate) by up to 2 years the appearance of lesions on T2-weighted MR images."
http://radiology.rsna.org/content/215/3/824.short

There is another technique called Diffusion Tensor (DF) MRI that looks for water, but using a similar science used in Doppler ultrasound, not only measure the amount of water (magnitude,) it measure the direction the water is moving.
Something with a starting point, a magnitude and a direction in 2D is a vector.  In 3D space, it would be a tensor.  
DF MRI,  can be used to map nerve fibers bundles and can be used to visualizes the damage caused by infarcts, MS, Alzheimer Disease, epilepsy, etc.  

Both of the above techniques also have been used to demonstrate that MS is also a Grey Matter disease.  The improved contrast of these techniques allows MRI to visualize Grey Matter changes lost using conventional MRI techniques  It is through techniques like this that many neurologists will tell their MS patients that: "We can't see the lesion on MRI, but your symptoms tell us there is something there."  Well, they may actually be able to see the pre-lesion.

These techniques are available on many 1.5T and most modern 3T machines through the machines software.  They are rarely used outside of research and neuroimaging centers.  They do require some special training to perform and read the studies. They also require more time, but there have been a few studies that have shown them to be less expensive in terms of health care costs by improving the diagnostic accuracy rather than many repeated MRI studies and delays in diagnosis.  

I'm guessing doctors, patients, Governments and insurance companies have not complained loud enough or made a good enough cost case to make this part of the "standard of care."  I'm not sure I can blame the doctors too much.  I have no idea if this is really taught in Med School or Residency programs.  Even in this forum, we concentrate on T1, T2, PD, and FLAIR MRI techniques.  I have mentioned STIR (Short TI Inversion Recovery)  and SE (Spin Echo) a few times, but there are many other techniques that exist but are not in the "table of common tests" that can be performed on conventional MRI machines.

What do you think?

Bob

[lsichitiu]

I just saw my neurologist and he told me that my MRI is good and that the stuff I see is either artifacts, or stuff in the gray matter area and that MS does not affect the gray matter.
So your post lets me even more convinced that I should look for another doctor. He did schedule me for an LP and VEP and SSEP next week. I wonder why, if he is so convinced I do not have MS .
Thank you for such an informative post.

[jensequitur]

I would love to see more options available to neurologists for diagnostic purposes.  As you say, there's lots of information available - if the technician is properly trained to perform the study, and the radiologist is trained to read it.  

Unfortunately the training for neurologists is so erratic and inconsistent that I fear it would just confuse matters further.  We already have a problem with lesion-counting neuros, that can't be bothered to do an actual neurological exam - or don't trust the neurological exam when the MRI comes back clean.

What I want to see is more consistent training for neuros to diagnose MS, and better and more consistent ways of treating MS.  

I would like to see OCT being used more often as a diagnostic tool, and as a way of tracking progression.  It's much cheaper than MRI, and more accurate.

Have you ever heard of fMRI?  It's another technique that measures gray matter changes in your brain.  I think it actually sees the increased iron deposits in the gray matter.

[sllowe]

Only once did I get anything special beyond traditional sequences. Felt it was the tech who was more than happy to complete STIR and Spin and 3D.  And, another one or two that offhand I'm not remembering (I'll ck my report when I can).

It didn't require a stronger magnet, it didn't cost addtl. money. Just required someone willing to work the magic on that traditional!

thanks,
Shell

[JemmAus]

Huh? It's dawn here. You lost me at "tensor calculus" LOL