Have had 3 MRIs:
Both knees, one open and one closed. The closed one was definately louder, and took longer.
I had my cervical area done, and they do closed. It was very scary. I didn't think it would bother me, but the top of the tube was about 2 inches from my nose. I was in about 5 min or so, and told them to stop, since I felt like I was having an anxiety attack....Took some deep breaths, closed my eyes, and did some slow breathing, and was fine. I think I just didn't realize how close it was going to be, but once I prepared myself I was fine.
Good luck with your testing
Didn't have dye with any of them, but had a CT scan of my head once, and when they injected the dye, it felt like someone poured hot water in my crotch.........Oh my, very strange!!