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147426 tn?1317269232

MRI's, Lesions, & Symptoms

MY QUICK AND DIRTY EXPLANATION OF HOW MRI'S SHOW LESIONS IN MS

The Life History of an MS Lesion

MS does it's damage by causing the nerves in localized areas in the brain and spinal cord to lose their protective sheaths, called myelin.  At first, when the myelin is being attacked, the body brings a higher blood supply to the area to fight the attack and the area becomes iswollen and inflamed.  These areas now become "lesions."  At this point, when they are inflamed and blood engorged,  they are called "active lesions."   At first the nerves, themselves,  haven't changed much and they appear (and have the same density) as the healthy areas around them.  The body attempt to repair the damage that is being done and sometimes these areas re-myelinate.  They may disappear from the next MRI.  They aren't perfect in their function, but the area may return to a normal appearance.

If the nerves do not remyelinate and the damage continues, for a long time the lesions sit as scars.  These scarred areas have damaged and dying cells in them, the blood supply shrinks, and the areas become more dense  - more dense than the normal brain around them.  These are the classic MS plaques and are considered old lesions. They show up as the bright areas most of us have seen in pictures and on our films.

If the attack on the myelin sheath is too strong for the immune system to repair, more and more myelin disappears and the area of nerves eventually dies.  Then it contracts and scars.  The blood flow is decreased to that area and the body tries to reabsorb the dead area.  It becomes "less dense" then the surrounding normal nerve tissue.  After a longer time - probably years - the scar can reabsorb completely and the area becomes "empty."  It's called a black hole.

How the MRI Shows These Different Stages of MS Lesions

When you image these lesions with an MRI you can see different things, depending on the technique, the age (stage) of the lesion, the power of the MRI, and whether contrast is used.

The first MRI image is done without contrast.  This technique will show old lesions that are big enough to be seen by the power of that MRI machine.  WE KNOW that many lesions in MS are too small to be seen.  If the newer, more powerful MRI with a 3 Tesla magnet is used many more lesions will be seen (by at least 25%) than on the older 1.5 Tesla machines.  The classic old, scarred, mature MS lesion is a little bit oval, will have well-defined borders and will be in the white matter.  Characteristic places (but not the only places) are subcortical, peri-ventricular and in the corpus callosum.  The classic MS lesion will also have it's long axis perpendicular to the ventricles of the brain.  Also, important and very symptomatic lesions are found in the brainstem, the cervical and the thoracic spine.  The spinal cord ends at the bottom of the thoracic spine, so there is no such thing as a lumbar spinal cord lesion in the normal spine.

The  scarred lesions will show up as light, bright areas.  These are the classic, MS lesions or "plaques."   But, with just the regular MRI image one can NOT say if it is old and dormant or if it has active inflammation in it.

Now the very old, scarred ones that have been reabsorbed will show up as a black (empty) space or black hole.  If there are many of these empty areas the brain will contract around them eventually and show up as a loss of brain volume.  This is also know as brain atrophy.  This is particularly seen in the progressive types of MS.  In brain atrophy there will be an increased space between the skull and the brain.  Also the deep folds in the brain will appear widened.  

However, a newly active MS lesion may not show up on a regular MRI because the area of nerves, though inflamed, is still pretty much intact and has normal brain density.  On the MRI it will look like normal brain.  Without contrast it won't show up and will be missed.

When the next phase of MRI is done the contrast is in the blood vessels.   Anywhere the blood vessels are more dilated than usual,  bringing more blood to the area, as in inflammation, the areas will "highlight"  or "enhance."  They show up as even brighter than the brain around them and brighter than an old, scarred lesion.  So new lesions will show up as "enhancing," or "active".  Also, older lesions, that have undergone a new attack right around them (also called reactivation) will show an enhancing rim or ring.  When you compare the regular MRI to the Contrast MRI you can see this reactivated, old lesion.

That's how some reports can call active lesions or some report no newly enhancing lesions  (these say the same thing).  Also since some new ones heal they can be compared to old films and show they disappeared.  In addition, between different sets of MRI done after a time has passed, the radiologist can see an increase in old and in new activity.

Please ask question where I haven't been clear.

Quix
84 Responses
147426 tn?1317269232
WHAT IS THE DIFFERENCE BETWEEN T1, T2, AND T2 FLAIR IMAGES?

Arggghh...  Okay, I  was looking up for a good description and didn't readily come across an easy one.  I did find a thorough discussion of the T1 - T2 topic.  It is a deeply scientific matter of mathematics and physics and trying to read it made my brain hurt!  :(  So, I will describe what I understood.  Where the stuff is really technical (ie. I don't understand it) I will just refer to the "miracle."

The T1-weighted images and the T2-weighted images refer to the different rates and strengths of the electromagnetic pulse that is sent through the body to the EM receiver.  There are long-strong pulses, short-strong pulses, and long and short weak pulses.  In a miracle the machine and the programmers use these different pulse/spin sequences to make the different tissue structures in the body stand out from each other.  In the 20+ years of studying the miracle they have discovered that different tissues (brain, bone, liver, blood, etc) all show up best using different combinations of pulse techniques.   They have also discovered that certain combinations of techniques show abnormalities like tumors or scars or whatever.  That's it, folks.  I can't get any better than that.  I do know that T1 images show the CSF to be white and the brain medium-gray and the bone black.  T2 (which I think are the most commonly displayed) show the bone to be white, the brain medium gray, and the CSF to be black. (they are flip-flops or positive/negative of one another)  But the computer, during a miracle, compares these two and further delineates (distinguishes) things that weren't really apparent on either type image alone.

The T2 technique is the best for showing the mature, scarred lesions, where the oval lesions look brighter than the surrounding brain.  The T1 is best for showing the old, reabsorbed "black holes" where the lesions once were.

The FLAIR is a little easier for me, but still involves a miracle happening.  It stands for FLuid Attenuated Inversion Recovery.  It is part of the T2 imaging, with a twist. It is another miracle of pulses and signals.  It's purpose is to distinguish things that border on areas of fluid (mostly for our purpose - CSF in the ventricles).  Apparently a lesion right up against the ventricles can blur out and be missed.  The FLAIR technique recovers information and through a miracle makes the lesion show up.  There!  Here is the link that made my brain hurt:

http://spinwarp.ucsd.edu/neuroweb/Text/br-100.htm

There are other techniques like fast-spin. spinm echo and such, but they are techniques used to clarify tiny differences in the tissue and to make lesions stand out better.

Quix

147426 tn?1317269232
WHAT IS THE DIFFERENCE BETWEEN THE OLD MRI's AND THE NEW 3T MRI?

I came across a good back-to-back comparision of the 1.5T MRI versus the 3T MRI on MS patients with known multiple brain lesions without enhancement.  They did an MRI using the MS protocol of  thin slices.  The neuroradiologists reading the films were not told which machine they werE done on.  The 3T machine consistently picked up more lesions - on average 25% more.  

Now if you already have 8 lesions, and we know most brain lesions are not "eloquent", that is, they don't cause recognizable symPToms, who cares if  there are 8 or 10?  In the vast majority of cases the increased number of lesions picked up does not affect the diagnosis, the treatment, or the prognosis.  So there isn't a huge rush to convert to the newer and more expensive machines.

However, I make a big deal of the issue here for the reason that several of us, including me, have languished without a diagnosis because of having "no" or "not enough" lesions on the MRI.  If you are in diagnostic limbo and everyting you are suffering from screams "Multiple Sclerosis", but the MRI is not diagnostic, you need every bit of increased sensitivity you can get.  Even several of our neuros have told us regretfully, "You might have lesions that are just too small to be seen."  WELL??

I again tell the same, old story  about this spring.  I had ZERO spinal lesions on a 1.5T machine in March. In April I developed a fairly severe L'Hermitte's sign (lighting zaps down my left leg when I fllexed my neck)  This is a common in MS, but non-specific sign of  cervical spine nerve lesions.  My neuro ordered a repeat MRI ofr the spine on the 3T MRI.  Suddenly there were SIX old (non-enhancing) lesions.

T-Lynn had no lesions, but classic disease for years.  Suddenly she had "brain atrophy".  Her first MRI sign was the accumulation of so many old, reabsorbed (and invisible) lesions, called "black holes", that when the brain tissue contracted around them the MRI showed loss of brain volume!  After this diagnosis they did an MRI on a 3T machine and she showed lesions thoughout the brain.

Granted it's only two cases, but it is two cases where the diagnosis was delayed and we were dismissed by the neuro's as being crocks.  In the faced of the "undiagnosed" that small increase in resolution becomes very important.  When someone looks at the pictures, like a tech, they may not look that much clearer.  What the tech does not see is the comparison back to back on old and on new machines, and what the appearance of just a few more lesions can mean clinically.  There's no way they could see this.

It is more than the art of interpretation, though that clearly makes a difference in the overall picture.

I think a lot of doctors do not want to admit that they have been missing diagnoses, even if the reason is beyond their control.  They don't want to admit they don't have access to better equipment, so they deny it is better.  Yes, I have sat in the doc's lounge and heard discussions and rationalizations for more than twenty years.  Doctors in general, and neurologists in particular, can have huge egos and need to "save face."

We also must remember that the vast majority of the some 400,000 people in the UK and US with MS were diagnosed using the older equipment.  For them the new one wasn't needed.  We here, who are just lacking sufficient MRI evidence are the one's most likely to benefit from use of the higher resolution machines.  

Final word (really??) If the signs and symptoms are suggestive and the MRI bafflingly negative - why not go for an image with a better resolution.  Quix
147426 tn?1317269232
SHOULD THERE BE A LESION SEEN ON MRI FOR ALL OF MY DIFFERENT SYMPTOMS?

NO!

Right now it seems that one of the most difficult questions on the forum is whether the lesions seen on the MRI's are supposed to be directly related to the problems that people have, their symptoms and their signs.   The answer is THEY ARE NOT PERFECTLY RELATED.   Too many doctors, neurologists, and people try to draw conclusions about this.  It is probably the greatest pitfall in understanding the disease of Multiple Sclerosis.

THE BRAIN

First, lets talk about the BRAIN.  Remember that about 90% or so of our brains are "unused."  That means that we don't know what those areas do or might do if they are damaged.  ALL of the scientific articles are clear that the majority of MS lesions in the brain are not "eloquent", that is, they don't "speak up" with specific symptoms.  No good MS Specialist is going to try to map the lesions with the symptoms that are showing up in the patient.  It is almost impossible and it is a waste of time.  It is well documented that some people with many, and severe symptoms may have few visible lesions.  And some people who are diagnosed when they have just one symptom may have a whole brain full of lesions which had never before "spoken up."

Now, some lesions can be big enough and in known active areas and we can recognize that they cause a specific symptom.  But this is the exception, not the rule.  MS "tends" to cause lesions within a characteristic pattern, but knowing this just means that when you look at a HUGE number of people with MS and plot all their lesions, the majority of lesions will fall into this pattern.  ANY ONE person or any person with just a few lesions may have them occur in any white matter location.  .  Even people with a "characteristic pattern of lesions" will have some that don't fall into the perfect "zone."   Please reread those last two sentences.

The more the lesions follow the common pattern, the easier the diagnosis and the easier the job of the neurologist.  It's those people with suggestive symptoms and suggestive abnormalities on physical exam but WHO HAVE NO LESIONS, VERY FEW LESIONS, OR LESIONS IN LESS USUAL PLACES that will have a tougher time with the diagnosis (if they have MS).  

Secondly, all good MS doc's will tell you that they believe that many brain lesions are still invisible to the MRI.  So we know that there are some lesions that can't be seen which can still cause symptoms.  So that makes drawing conclusions IMPOSSIBLE between where the lesions in the brain sit and what the symptoms are.  But, sometimes they can form generalities.   Some researchers have found a statistical relationship betwee frontal lobe lesions (which is not one of the commonest places) to the very debilitating fatigue. Lesions in the brainstem are often associated with balance problems or spatial orientation problems.

The point to take home:  Most lesions seen in the MRI of the brain do not correlate well with the problems the patient has.  A good doctor will not try to tell you different.  And you shouldn't spin your wheels trying to look up mapping of the brain - unless that is something you would do anyway for giggles.

THE BRAINSTEM AND SPINE

The nerves in the brainstem and spine are all "eloquent."  They drive the functions and the movement of the body and they relay information from the body back to the brain.  A small area of damaged myelin in the spine is "more likely" to cause a direct symptom or problem.  Spinal lesions are a little less common than brain lesions, but more directly connected (in an obvious way) to our disease.  But, also many spinal lesions are still invisible.  They are also harder to get good clear MRI images on.  This is one area in which the newer T3 machines seem to excell.
147426 tn?1317269232
I was up late last night, so I consolidated all the MRI/Lesion stuff into this thread.  It will be easier to point people toward answers.  What do you think? Q
147426 tn?1317269232
Focus - a spot

Foci - more than one spot

Increased signal - abnormality, usually referring to a lesion

enhancement - area of increased blood flow, inflammation, (in MS) new and active lesion

UBO - Unidentified Bright Object - a bright area, lesion, not specified.

lesion - abnormality, area where the tissue shows change (may be scarring, missing, more dense)

T1, T2, FLAIR - different imaging techniques

peri-ventricular - something aligned along/near the edges of the ventricles (which are the CSF fluid filled spaces in the brain)

perpendicular to the ventricles - a lesion which is usually oval and has the longer axis pointing AT the edge of the ventricle.

gray matter - The thinking cells around the outside of the brain - the cortex

White matter - the communication network joining the thinking cells.  The white matter are the long nerve fibers and the white is the fatty, myelin sheath of the brain and spinal cord.

Do it yourself MRI report interpretation.

Quix
220917 tn?1309788081
Wow.  You should write a book.  I know how hard that is for you, with the vertigo and diplopia and fatigue.  That was so great of you to do.  I'm at work.  Shouldn't be reading it.  And rereading it.  

The definitions put eveything into context, thanks.  Still don't really get the gray/white matter fully.  Is the gray matter just cells?  Are they sort of electric or just organic, whatever that may mean?  I get the white myelin more.  But does that include the long fiber inside the sheath?  Is that white matter?  That's got the sort of electric charge or exchange, right?  

Do tell.

Zilla*
228463 tn?1216765121
Thanks sooo much for all the work you put into this!!  It really helped me understand that I do need to eventually have the repeat MRI of Brain w/ contrast.  I am going to see my 2nd neuro tomorrow and was planning on asking for repeat MRI of Brain w/ contrast.

My question is this:  Since my initial attack ended at around end of June I have only had milder sx with "baby attacks" that focus around my menses.  These milder attacks include weakness, numbness, blurry vision, and tremors.  They have lasted around 2 weeks for the last two going on 3 periods now.   Should I wait until I have another full blown attack to have the repeat MRI done as there may be no activity now since initial attack is over?   My first MRI was done mid June without contrast only.

Thanks again for your help and knowledge!!  I am sorry you have been having trouble with your doctors again!  I get a bit discouraged when I read that even you a "rocket science" pediatrician who more than dabbles in neurology are having trouble getting them to take you seriously!!  Thanks for all your support and help!!

Take care and Hi to Momzilla and all the Gang!!!!!!!

Kristin
Avatar universal
Well done, Quix!  You have really put this in a way that we all can understand and I know everyone on this forum appreciates the time and effort you have put into it.  I like this DIY approach.  I also want to bump it up to the top again.
Cheers
Marcie


Avatar universal
Wow, I am impressed!  That took a lot of work.

I guess years of peds helped you figure out how to get it to a basic, understandable level. (helpful for those of us with congnitive issues).

Thanks for re-posting it!
263804 tn?1451104357
It would be a live dictionary and guide to me. Some of the points which I ask my doctor with no answer. And now, I do have a basic knowledge of MS. You are really the nicest person in the world.
251222 tn?1270939717
Quix this is fantastic, thank you so much. I have a couple questions, please forgive me if you have already answered it. I tend to get foggy and confused after reading more than one small paragraph at a time.

What originally causes the attack on the myelin in the beginning? Or do they know?

I have (right now) 2 doctors saying two different things. My personal doctor believes I have had/am having mini strokes and they are damaging the brain. Another doctor feels I have MS.
Does the damage from both diseases look 'alike' on the MRI? Or how does it look different if it does?


All the best
Jazzy


199882 tn?1310188142
Wow,  Thank you so much for all the hard work and time that this took.  You are the jack of all trades.  We are so fortunate to have you here and I think that because we have someone like you who is a MD and a MSer, well, that's why people come here and stay.  

So many forums have people like me who does'nt know a thing, and that's all they have.  After a while it gets boring talking to me.  You know what I mean.
I hate it when I can't type what I'm trying to say.  But, I hope you know.

We truely love you Quix.  Not just because your a doctor but more so because you are one of the kindest and most understanding person, that will go that extra mile to find out answers to our questions, I know.

We salute you and thank you!
Carol
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