I had two -two hour sessions in the tube. My Dr. gave me some Xanax because I'm claustrophobic. The first place has a smaller MRI tube. That REALLY sucked. I could barely move and was even "squished" at times. I found another place, where I had a second MRI of my neck done that has a little bit larger tube. One thing that also helped was a washcloth over my eyes. They will give you those sleeping masks for your eyes, if you ask for one. that worked, too. Bear in mind, I'm a fairly large guy, as Eupher, Schadie or Mike220 can attest.