Tests and treatments

Thyroid scan

Symptoms and causes

Symptoms and causes

What is it?

The thyroid is a butterfly-shaped organ, consisting of a right and left lobe, that drapes around the front and sides of the windpipe (trachea) in the lower part of the neck. The thyroid absorbs iodine from the blood and uses this to produce the thyroid hormones necessary for a well-regulated metabolism.

For a scintigraphy, a tiny amount of radioactive iodine (or a substance that the thyroid will take for iodine) is administered. The thyroid will absorb this and a camera is then used to take images of the thyroid. This allows the physician to assess the thyroid on the basis of form, position, size and function.

Pregnancy and breastfeeding

Are you pregnant? Do you think you may be pregnant? Or are you breastfeeding? Please tell the physician before the injection. The test will not be performed if you are pregnant. If you are not sure whether you are pregnant or not, the test will be postponed until you are certain.

If you are breastfeeding, make sure to discuss this with the physician before the test. You will receive additional instructions about how to avoid unnecessary radiation exposure to your child.


  • This test cannot be performed if you are pregnant or if you think you may be pregnant.
  • No fasting is required for this test.


A radioactive tracer is injected intravenously into the arm. There is no danger of allergic reactions or other side effects. After approximately 15 minutes, you are placed beneath a gamma camera that will perform imaging of your thyroid for five to ten minutes.



There are essentially no side effects: the injected product causes no abnormal perception and may very seldomly lead to (very mild) allergic reactions. Allergic reactions are very rare and, even then, only occur in a very mild form. The injected radioactive material does constitute a dose of radiation, but it is very small.

The quantity of radiation that you are exposed to during the test is not higher or lower depending on the number of images taken.

The radioactive material will have disappeared almost completely from your body after a few hours. No specific measures need to be taken.


We prepare a report of the test. This report and the images are available digitally to the physician who requested the test.


More information can be found in the leaflet below.

Only available in Dutch:

Centres and specialist areas

Centres and specialist areas

Latest publication date: 16/05/2024
Supervising author: Dr Vermeiren Judith, Dr Van Den Bossche Bieke