Page 1 of 1

What's an Enhancing Lesion (in English Please)

Posted: Mon Oct 04, 2004 2:29 pm
by seelie
Wow...

This has been harder to figure out that I thought it was. I thought Google + the words Enhancing Lesion would lead me to the right answer... but I just got more confuzzled. There's this stuff about enhancing that appears to be some sort of MRI contrast fluid also.... and a lot of it was in Medspeak...

My neuro said he didn't like the MRIs I brought him and they would have to be done again HIS way... and he would be looking for enhancing lesions.

My gut tells me these are lesions that appear to be growing over time, but now I'm not so sure.

There's lots of knowledge out there... I know some of you know...

Thanks
=G

Enhancing lesions

Posted: Tue Oct 05, 2004 6:16 am
by treez
Seelie,

I'm no Ph.D. but here goes.............When an MRI is done, the first scans are usually done without anything to enhance the lesions. These could be 1 week, 1 month, or 10 years old, there is no way of knowing the age of existing lesions. After these scans are done, the radiologist(or whoever is doing your scan) will give you an IV injection of Gadolinium - A chemical compound which can be administered to a person undergoing an MRI procedure, to enhance the distinction between new vs old lesions. It also increases the scan's sensitivity, which enables the imaging of lesions that would be missed.

Gadolinium enhances active lesions more than existing lesions which will determine if a person has an ongoing demylination (experiencing an exacerbation) my neurologist tells me there is a small window of time when this will happen. Meaning, enhanced lesions are current demylination.

These are the basics, there are other options with an MRI, short of having a Radiologists knowledge, understanding all the details can get pretty mucky?

A note: Gadolinium is a radioactive isotope. It has a very short half-life, meaning it breaks down really fast. I'm told the risk of injecting such a thing is extremely minimal.

Laymen-terms enough?

Hope this is a help!

Treez

Posted: Tue Oct 05, 2004 6:56 am
by art
I'll add a couple of things to the above answer:

1. Gadolinium (Gd) is present in the injection and shows up on MRIs much more pronounced (hence the enhancing part). Because it is injected into your blood, it should not show up too much in your brain other than where there are blood vessels. But in MS there is an abnormal breakdown of something called th blood-brain barrier (BBB). This is a barrier along all the blood vessels in the brain that prevents most substances from moving from the blood to the brain. If your BBB is broken down (which we believe happens at the sites of new lesions), the Gd will get into the brain where you wouldn't normally see it. Thus you will see these areas more visibly on the MRI and we can assume those are the sites of new lesions.

2. I don't think Gd is radioactive. It's just magnetic in a way that MRIs like.

Here's a bit more on Gd
http://www.mult-sclerosis.org/Gadolinium.html

Posted: Tue Oct 05, 2004 7:18 am
by treez
Thanks Art

Sorry if I was at all misleading. Didn't figure I should go into T1 and T2 enhancements either.

I'm no chemist

Treez

Posted: Tue Oct 05, 2004 2:03 pm
by seelie
Ok... so "Enhancing Lesions" is essentially a verb not a noun?

No wonder this was making it difficult for me to understand what I was finding. I guess I was all around it.... but not quite there.

Thanks much Art and Treez... I knew somebody here would make this easier for me.

Regards
=Greg