I wouldn't have a contrast dye as its contraindicated for people with MCAS - which some of us with M.E/Lyme also have.
I agree with Justy to be honest. However, in my personal case I had no choice as they were unsure I had a brain tumour, a brain adenoma, or just a 'cyst'. Like so many PWME I have MCS so was concerned of a possible allergic reaction, but had to take the risk. On balance I think it's worth it, if you have something as drastic as possible fatal outcome with a misdiagnosis, unless the medics know for sure, what they're looking at.
In terms of side effects, I felt nothing at all during the IV under the MRI (unlike some radiological agents used in CT scanning for example that as others have said, make you feel like you've peed yourself!). I did however, get some nasty urinary urgency afterwards, as in the worst I've ever had, as in rather like a UTI (ladies will know) with a lot of pain, rather than just the 'urge'. So if you have Gadolinium, make sure to drink plenty before and especially afterwards to flush your kidneys out as quickly as possible. (Don't get too excessive and drink litres upon litres or you could alter your electrolyte balance).
From what I've read, the contrast agent using in brain imaging, (E.g. Gadolinium) is pretty dodgy stuff, although there are differing brand names made by differing manufacturers that seem to have slightly different safety records. I did my research and found out the best of the bad bunch of contrast agents. I then checked the hospital was using the 'best' type, rather than the alleged, 'worst' type. That, I guess, alleviated some fears. Gadolinium being a metal (magnetic) agent is hardly something we want to put in our veins, or brains (especially as Justy mentioned with Lyme - Lyme loves metals), but sometimes I guess we just
have to go with it.
Away from ME, Lyme, Contrast is a moot point for some patients as you all know I'm sure:.
Some are worried about the chemical (It's linked to
fatal kidney failure in people with poor kidney function) yet others don't mind the risk. I was worried, but then I had to take the chance that not having a reasonably clear diagnosis might be dangerous (Ruling out brain tumour!).
Technically, you can see general brain anatomy on a modern 1.5T MRI without using contrast, it's just harder to be accurate by not using it. So on balance for people who are worried, I would go ahead with it, if you have normal
kidney function. (It might be advisable to have a kidney function test before an MRI with contrast procedure to put aside any worries).
There are some people out there who simply won't take the risk of medical imaging procedures (understandably fearing an allergic reaction to the contrast agent, or theoretical long term damage by it not clearing your body properly), however, with an organ as vital as the brain, I'd not risk misdiagnosis considering the risks in neurology of getting it wrong!
If you've got a copy of your MRI done on the latest machines (most NHS hospitals let you have a CD-ROM for a small fee) you can see actually why contrast is used if you compare you pre and post contrast images, it's quite fascinating to see a small darker vs lighter image of certain brain structures - that is all the radiologists have to go on, to decide what is normal tissue vs a tumour or a cyst (water filled).
Cheers.
