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:
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.
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
SHOULD THERE BE A LESION SEEN ON MRI FOR ALL OF MY DIFFERENT SYMPTOMS?
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.
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.
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
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.
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?
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!!!!!!!
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.
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!
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.
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
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!