JesseHello and welcome to HealingWell. I have had several MRIs and I understand how being in the enclosed space can cause you to panic.
Couple of suggestions - perhaps you could ask your Dr. for a mild sedative to take prior to the scan. Judy mentioned she tried this. A quick acting sedative with a short half life would most likely work best for you and you can talk with your Dr. re what he feels would be a good choice.
Perhaps you can look into the open-sided MRI. The open MRI design eliminates claustrophobia.
From our resources you may want to look at these links to help you learn some breathing techniques.
Self Help sites with breathing/relaxation exercises instructions
Panic attack relief exercises:
http://www.healthyplace.com/
http://www.stress-relief-exercises.com/
http://www.ehow.com/video_4405003_breathing-exercises-panic-attacks.html
http://www.psybersquare.com/anxiety/panic_relax_I
Again a warm welcome and I hope you keep on talking with us as we are here to help.
Kindly,
Kitt