I had an MRI yesterday. I must say it was a lot easier to handle the close to 2 hours process than a year+ ago when I first was diagnosed. I do attribute this to my practice of yoga and meditation over the past 8 months.
Knowing that I had an MRI on Thursday, I took as basic gentle yoga class on Wednesday night. So on Thursday morning, my body was fairly relaxed compared to a typical week where I've been sitting at a desk every day for 10 hours.
During the MRI, I was able to disconnect my mind from my body and "go somewhere else". It went really fast... Not sure if this will work for everybody as IFwczs mentioned, but it's worth giving it a try. Yoga might help you relax and calm down your nervous system.