Has anyone had severe anxiety during and following an MRI?

Now, I do not consider myself an especially anxious person. I have never considered myself claustrophobic. In fact, I had a few CT scans in my early 20's and had no trouble with them. Well, let's just say the MRI is a whole different ballgame. I was not expecting such a small, confined space. So, they squeeze me in and I am shocked at how small the space is in there. It was very snug. I had intense panic for about 30 seconds. My biggest fear was not really the small space but I just had this fear of being stuck in the MRI. I am lying there thinking, "I am too fat - I am stuck in here! They won't be able to get me out!"

I spent the time in there using various distraction and relaxation techniques I have learned from woking in mental health. I can only say that I was able to stay in there and lie still for the 75 minutes of my test but I found it to be a real mental challenge.

Is this something others without a history of anxiety or claustrophobia have experienced?