I had a similar test done. It was called Glo-fill, though. I had to do it 3 times. They put an IV tube in my arm that they drew the blood from, like Orchid Lady said so they don't have to stick you each time. Then they drew blood from it as a baseline. After that, they injected the radiation, then drew more blood at 5 minute intervals...5 minutes after injection, then 10, then 15 minutes. After that, I was able to leave, and I had to come back 3 hours later. Then they did half hour intervals, the first one when I got back, then 30 minutes later, and then one hour after the first. I was told that the 3 hour interval could be longer, but its based on BMI. Overall it wasn't too bad.