On Tuesday, I had my second PET-CT scan. As before, I arrived at the hospital early and with an empty stomach. I was given the sugar fluorodeoxyglucose (FDG) and asked to relax for an hour. Ok, not quite right, I was ordered to lie motionless for an hour. The last time I had a PET-CT, this was so relaxing I fell asleep towards the end. This time, it was a bit less comfortable.Once inside the body, the sugar goes to places of high metabolic activity. If the muscles are resting, these are the brain, the heart and not...