Thyroid Uptake and Scan

What is a thyroid uptake and scan?

A thyroid uptake and scan measures the function of your child's thyroid gland. It also gives us information about the size, shape and structure of the thyroid.

Your child will swallow a radiopharmaceutical capsule. We will take the measurements of the thyroid two to four hours later, and again the following day. Depending on the reason for the exam, we may also take images of the thyroid on the first or second day.

The radiopharmaceutical is medicine combined with a small amount of radioactive material called a “tracer.” It travels to the area of your child we need to examine.

Radiopharmaceuticals are carefully tested. The risk of side effects is extremely small. Most radiopharmaceuticals used in nuclear medicine studies give less radiation exposure than a day at the beach.

What should you do prior to your child's exam?

Your child cannot have anything to eat or drink four hours prior to the exam.
Your child should eat a low-iodine diet for three days prior to the test as specified by the ordering physician. Your child should not eat fish or other seafood, added salt, frozen or canned foods, seaweed or kelp.
Your child should not receive radiographic contrast agents two to four weeks prior to the scan.
Your child may need to discontinue thyroid medication for up to six weeks prior to the exam, as specified by the ordering physician. Please call the Nuclear Medicine Department to ensure that any medications your child takes do not interfere with the exam.

Note: Parents will be allowed to accompany their child into the exam room. It may be helpful to make other arrangements for siblings.

What should you expect during the exam?

The technologist will ask why the thyroid uptake and scan is being performed and will explain the exam to you and your child.
Your child will be given a radioactive iodine capsule, which helps measure the function and size of the thyroid. In rare instances liquid can be given in place of a capsule. This must be known when scheduling the exam.
You and your child may take a break and may leave the Nuclear Medicine department. The technologist will tell you what time to return for the imaging portion of the test, usually from two to four hours later.
We will measure your child’s thyroid by placing a special probe on your child's neck. Images may be taken at this time. The measurement helps to determine the function of the thyroid. Another measurement will be taken 24 hours later. Images may also be taken at this time.

If you’d like, our child life specialists will help you prepare and support your child during the procedure. We can also arrange to have a child life specialist at your child's appointment to explain the procedure in developmentally appropriate ways and to help your child better cope with the stress of the hospital experience.