How is the thyroid scan performed?

2 types of "scans": Thyroid ultrasounds are quick and painless. They are done with some jelly on the neck and sound waves are used to visualize the thyroid and surrounding tissues. Nuclear medicine scans are done by swallowing a small amount of radioactive iodine. After some time, the iodine finds its way to thyroid tissue and "lights up" on the scan. This is painless, safe, but does take a while. Best wishes.

2 kinds of nuc scans: In addition to ultrasounds, which are sometimes referred to as scans, there are two different kinds of nuclear thyroid scans done. One kind uses radioactive iodine (i-123) and is given as a pill. The other uses technitium (tc-99) and is given as an intravenous injection.

Radiotracer + gamma: For a nuclear thyroid scan, you are administered a radiotracer either by mouth (typical for radioiodine) or IV (for tc99m pertechnetate). Some time is allowed to pass in order to let the thyroid take up the radiotracer. Your thyroid is then imaged using a gamma camera. For a pertechnetate study, it takes about an hour. For a radioiodine study, it may take a couple of days to allow adequate uptake.