Wow I feel deeply for you mate. I went through a tough heart procedure yesterday that required my arms stretched over head for two long sessions without moving. In between other things like nuclear injections etc. On the second time through and the last session as soon as the main camera sessions finished I screamed,the pain was excruciating, then they fed me right into a solid tunnel twice. I am tall and arms back and shoulders scrunched only just made it in and out. Apparently I have osteo arthritus in the shoulders to add to my increasing list. The machine looks like a normal scanner on steroids with two fat Cameras? in a v shape outside the tunnel that take pics? at right angles all round the body. It was called a chemical induced stress test, sure worked on me. Four hours of the worst.
This pain you suffer I understand mate, take care Bill,
Peter.