I know well, what you are talking about. As the earlier post said, all the Drs. I have known gladly give you meds for sedation. My Ortho. gives me 2 valium. He says to take 1 1/2 hr. prior and 1 when I get there. I also have to have a dark mask over my eyes. I take my own, since there was 1 time that the hospital could not locate thier mask. Also, I got an eye mask that has a strap. That 1 time they couldn't find thier mask, they offered a wash rag and it fell off and I literally "freaked out". When I go in to the room, I can not look at the inside of the machine. I sit down w/ my back towards it, and put on the mask before they lay me down. They also have a panic button they will give me, if I ask. It goes inside w/ me and if I have to get out, they can be in the room and have me out w/in 10 secs. I always ask for it, but have never needed to push it. (have come close, but have always made it w/o having to do so). I also bring in my own CD and ask them to put the volume up higher than normal...to over power the noise of the machine. Once I lose focus on the music, I'm gone. If I start to realize where I am...my heart goes wild and I start gasping for air. Not a pleasent site or feeling...as I am sure you can understand.
If all else fails, ask for an open MRI, but know that they do not give the best readings. My Dr. told me that and then I did several searches on the web regarding the results and they all seemed to say the same thing. They are good for people who can not get an MRI the in the normal ones, but they are not as good or accurate when it comes to the results.
Good luck and keep us posted,