I had an abdominal ct with contrast yesterday morning too. I still have my whacky thyroid and didn't think much about it cause I had so much else going on and this was one of those rush thingys and I didn't get a chance to read up on it. I did tell the tech that I am hyperthyroid. My thyroid has enlarged enough since yesterday that the hubby mentioned it this morn. I am a little bit concerned too.
The one thing I did find out is that that iv contrast is a wonderful diuretic. It got rid of quite a bit of my excess water.
Now, if your thyroid is not present or has been destroyed (you did rai, didn't you?), like sue said, there is nothing to take up the iodine, so there should be no problem.