Yes, I have had several MRIs and although you may get anxious, all you feel is a little warmth as the dye is injected. The tech usually goes very slow and monitors you every minute. Just think about having one done on your head...yes, they did determine that I had a brain! LOL
If you feel really really anxious, maybe they can give you a Xanax or a little bit of Valium before they start the test. There is also another sedative that is like "twilight sleep" that I wish I could keep an IV full of at home...I get more "rest" during that time than at any other!!
Good luck with your test!