Thank you J.
Fortunately I managed to stay awake. To be honest I was a bit concerned about having involuntary movements. I get what look like sleep starts but I'm awake. I was concerned I may have spoiled the scan if I had one. I did have a two or three but I was assured they were able to compensate for them.
It did seem strange that my wife had to leave for the last part of the scan. The scanners moved a couple of feet away from my head before spinning, and then I was moved further into the scan until it covered the top half of my body.
I guess I'll find out what it was all about eventually. I should have asked them, but it had been a very long day and I just wanted to get home.