The dye is used for MRIs (gadolinium) is totally different than the dye used for CT's (iodine).

I was told the allergic ratio for gadolinium is quite low. But the tech's are always on the look out for any reaction to the iodine. You'll be asked if you have any allergies to shellfish as they have a high iodine content.

When I told the tech I was 'probable' MG - they mixed up what they called 'contrast light'. Don't actually know what that is but they said they use it for anyone who has either had a reaction or may be likely to either have a reaction to contrast dye or be stressed by it.

No matter what dye they use, always drink tons of water in the 24 hours after to be sure your kidneys stay safe.

Good luck with your test!