Iodine-131 thyrogen stimulated whole body thyroid cancer imaging after surgery

What is this test?

It is done to find out if you have active residual thyroid tissue and/or thyroid cancer tissue. It helps your doctor decide if treatment is needed.

Your appointment

If you make any changes to your insurance before your appointment please call Registration at 1-866-309-0832. This will help lessen delays and the need to reschedule your test, as many radiology services need a pre-authorization. 

Take Elevator H or I to level 3 Nuclear Medicine Center. It is between elevators H and I. 

Please call Nuclear Medicine at 1-319-356-1911 if you:

  • Have questions
  • Cannot keep your appointment
  • Cannot do the prep listed below or think you may be pregnant
    • You may not be able to have the test, or it may need to be rescheduled

Getting ready for your test

Before your test, tell your doctor or nurse if:

  • You are pregnant or think you may be pregnant, or if you are breastfeeding.
    • You may have to give a urine sample if a pregnancy test is needed.

Skin Prep

Do not use iodine tincture two weeks or betadine one month before your test.


  • Two weeks before your test, start iodine diet.
  • Do not eat or drink for four hours or two hours after your thyroid test. You may drink water.
  • If you have any other test today where you are told not to eat or drink for a longer amount of time, follow those instructions.


  • Stop taking dietary supplements with iodine, such as vitamins, minerals or kelp, at least one week before your test.
  • Talk to your doctor about how to take your thyroid and other medicines. If you are getting Thyrogen injections, you can take your thyroid medicines. Often you will stop these medicines before your test:
    • Synthroid six weeks before and start taking Cytomel as prescribed by your doctor.
    • Cytomel two weeks before.
  • Six to eight weeks before your test, do not have:
  • Diagnostic x-ray studies where you are given dyes by mouth
  • CT studies where you are given contrast in an IV
  • Intravenous Pyelogram (IVPs)

What to expect

Day 1, Friday 

  1. Go to your primary clinic for lab studies. You will have a:
    • Pregnancy test if you are of child-bearing age (female organs and age 11 to 54)
    • Thyroid-stimulating hormone (TSH)
    • Thyroglobulin
    • Anti-Thyroglobulin
  2. Go to Nuclear Medicine at your scheduled time after your lab studies are done.
  3. You will drink a diagnostic dose of Iodine (I)-131. There is no reaction to the I-131 dose.

This will take about 60 minutes.

Day 2, Monday

  1. Go to Nuclear Medicine for the I-131 whole body scan. The whole body scan is done using a special machine called a gamma camera. The camera:
    • Does not emit any radiation.
    • Will be close to your body while the pictures are taken.
Last reviewed: 
August 2018

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