No you are right. I was more thinking along the lines of hydrogen in general being used if it could be. You are also correct on the procedures etc. Part of my job is I am a Medical Gas AP so I am authorized to work on pharmaceutical, technical & medical gases so I know exactly what you mean in regard to management procedures.

Oxygen units gaseous form only becomes dangerous when it makes up 23% (it only makes up 21% of the air we breath) of the surrounding atmosphere. Oxygen arrives at hospitals in liquid form and goes through a process to turn it back into a gas which is easier to move through the hospital. Also, gases such as nitrous oxide, entinox (50/50 nitrous oxide and oxygen) and heliox are generally present in them. Hydrogen lines have a whole new set up to work on. For example releasing hydrogen gas you have to put it into a bucket of water and release it that way not straight into the atmosphere.

First off it should be NMRI but they drop the N part (nuclear) as it sounds less scary for patients! Secondly, there are out there MRI machines which dont need Helium. I have recently worked at a hospital which had 2 installed one was helium free the other traditional helium cooled.