Then you have to sit very still for an hour while they put a tracer in you. Its radioactive, which is why you are shut in the room on your own.
There was quite a wait to get started as I was the first appointment of the day and the stuff they inject you with had not yet arrived from Melbourne, it gets sent every day from the mainland.
I was much better at keeping still this time - I've had a lot of practice since then. I put double J on the TV and just rested.
After that, they take the cannula out (hooray!) and you have the scan. You lie on a bed for 20 mins while it moves through a tube. Once again, I found it much easier to keep still this time.
Then they keep you around for another 10 mins just to make sure you're OK and then you're free to go.
You have to fast from midnight the day before, so the first thing I did when I got home was eat!
I spent the rest of the day resting, which I think is kind of funny as PETs have to be one of the most restful kinds of tests you can have.
And now we wait.