How MRI's Show MS Lesions

[Quixotic1]

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

I am going to overexplain the MRI with contrast / without contrast thing again, so that you and your husband can have it as clear as possible in your minds.

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 inflamed.  These areas, now become lesions.  At this point they are called "active lesions."   At first the nerves haven't changed much and they appear (and have the same density) as the healthy areas around them.  At this point after some time, probably months, the body CAN repair the damage and remyelinate the nerve.  This repaired nerve still won't be as good as new, but the lesion "looks" like normal brain.  Sometimes later an old scarred lesion will "reactivate" and the adjacent areas will inflame and have increased blood flow.

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 area becomes "less dense" then the surrounding normal nerve tissue.  After a longer time - probably years - the scar can reabsorb and the area becomes "empty."  It's called a black hole.

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 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, mature MS lesion is a little bit oval, will have well-defined borders and will be in the white matter.  Characteristic 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.

These scarred lesions will show up as light, bright areas.  These are the classic, MS lesions or "plaques."

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.

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.  So the large blood vessels show up, too.   Anywhere the tiny blood blood vessels are more dilated than usual, as in inlfammation, the areas will "highlight"  or "enhance."  They show up as even brighter.  So new lesions will show up as enhancing, or active.  Also, older lesions, that have undergone new attack right around them 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.  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

[AlexSchmalex]

Hi,

I am a 20yr. old girl and  have recently been having symptoms that seem very characteristic of MS, but have not yet found out my diagnosis. The symptoms have been occurring periodically for 3 weeks and include tingling in my hands/arms, feet, and face. They spring up usually in the afternoon or evening and seem to worsen progressively over a few hours and then gradually diminish if not resolve completely over another few hours. Sometimes I go days feeling normal, but for the most part it has seemed like something has been tingling at any given time throughout the 3 weeks. The attacks that I have been experiencing usually last only hours (and therefor seem to not be relapses of MS), but sometimes I'll have tingling that remains in my hand or foot for days after all the other symptoms have become resolved. I got an MRI exactly one week after the first attack and the MRI report from the radiologist said everything was "normal," but I don't know what the strength of the machine was. I am currently waiting to see a neurologist and hear their interpretations.

My question is:
Is only a week after the very first symptoms too early for lesions to be large enough to show on an MRI?
Also, does the fact that my symptoms usually resolve in anywhere from 4 to 12 hours mean that I could have lesions that are too small to show on an MRI and do they seem like MS relapses?

I also wanted to say thank you. I have been obsessively researching the symptoms for and information about MS since my first attack and have been confused about many aspects of what I have read.
One of these confusions was whether or not lesions would only show WHILE symptoms were being experienced (because my MRI was done at a rare moment of complete normality for me).
Your clear and understandable description as well as your answers to many of the other questions asked have been such a relief to much of my frustration of reading other articles full of medical mumbo jumbo.
In what has been one of the scariest times of my life (being in limbo of not knowing my diagnosis), I really can't tell you how much it means to me that people like you are here to make it just a little easier to educate myself about what is happening to me.
Thank you so, so much.

-Alex

[Lulu54]

hi Ginger and welcome.  would you do us the favor of copying what you wrote and reposting is as a new thread?

this is apretty old disccusion and few people will take the time to go back and read new comments.

Also, Quix is on leave right now, and putting this in a new thread gives others the chance to help you with their replies.

I'll be watching for the new one.......
Lulu

[Ginger1965]

Hi.  I'm feeling very awkward putting this on a blog, but peace of mind is worth more than a few moments of awkwardness.  Several years ago I had some really weird things going on physically.  In short, the mri revealed 1 round spot on my brain in 2004.  Then, 2 years later there were 4.  Very small, very round.  I was told that MS lesions are crescent and these may just be "aging" spots.  I'm 46.  Recently, I've experienced nerve damage to my left foot; it has been getting worse.  I've lost range of motion.  It tingles, burns, and shoots pain up my leg.  I cannot sit on my feet without jumping from the darting warm, burning sensation that pricks as it spreads out.  I've sustained no injury to this foot, although there is a benign tumor in my big toe.  Most of the daily pain is located on the sesmoid (sp) bones which are regularly inflamed.  I've been to 3 foot doctors.  Only one has taken my "pain" seriously.  He has ordered orthodicts and I've spent 8 weeks in a walking cast.  I hadn't given those spots much thought until he told me the nerves were damaged.  Now, I'm concerned.  I should also be forthright in sharing that I probably have a conversion disorder, but I firmly believe with counseling that I am able to differentiate this issue.  It manifested itself in "seizures", and as soon as they told me what it was, it stopped and my "alert" is always on for such physical manifestations.  This is my question, should I be concerned about the foot, or should I simply brush it off as a conversion disorder manifestation?  
Thank you,
Ginger

[crazydaisy172]

I am a 34 yr old mother of 2 and am so scared and convinced that I have MS.  All other blood tests were normal, and I go for an MRI this week.  I have have pin/needles sensation all over my body and burning in my feet that comes and gos.  Memory is declinging too, and arms feel heavy at times.  I am very fatigued and sometimes have dizzy spells.  What could this be if it's not MS, because all this signs point to it?  crazydaisy

[woozy16]

ok that went wrong :)

I agree the symptoms are still there and annoying/bothersome, but everytime i go for tests it seems they either disappear or don't show up in tests and then i feel stupid, am told it's in my head, i am imagioning it etc,

the irony is that Dr's find them when they are not looking for them haha.
I spose if anything i am now thinking they are taking everything from the last 5yrs and kicking out all other theorys and then i go for these test and nothing shows up again i am left where this all started with no answers and the feeling that i am infact going mad.

woozy16

[woozy16]

Hello,