Don, so many places have different instructions, as do the different staff members. I was just called, finally lol, for pre-treatmnt instructions, no carbs, which is different than low carbs, which others have instructed, I can drink water (my CT for stomach was no water) in fact, at another location I have to drink 16 ounces of water an hour before arriving, no gum chewing, no exercise, which I didn't do since yesterday. No one mentions brushing teeth or rinsing with mouth wash, but doing so may cause uptake from movement, and coat the mouth with sugar? Oh, and this new place likes to do CT contrast, bedsides the FDG-18 nuclear glucose tracer, but I can't do the CT contrast due to my kidneys, so they give me the barium swallow stuff, which I get to choose which flavor lol. This is probably my 13th scan. Maybe this time I'll be lucky.