Thyroid scans are a test used to evaluate thyroid function.This test is performed by taking a medicine with radioactive capabilities, such as iodine 131, iodine 123 or technetium 99m, and with a device to capture the formed images.
It is indicated to assess the presence of thyroid nodules, cancers, look for causes of hyperthyroidism or hypothyroidism or inflammation of the thyroid, for example, know what are the main diseases that affect the thyroid and what to do.
- Thyroid scanning is done for free by the SUS.
- Or privately.
- With an average price starting at 300 reais.
- Which varies greatly depending on where it is performed.
- After the procedure.
- The final thyroid images can be described as shown in the following figure:.
The images formed depend on the absorption of the radioactive substance by the thyroid and, generally, greater absorption with the formation of brighter images is a sign of a more important function of the gland, as can occur in hyperthyroidism, and below-normal absorption is a sign of hypothyroidism.
Thyroid scanning can be used to identify conditions such as
The scanner is one of the tests that evaluate your thyroid, and your doctor may also order others to help with your diagnosis, such as blood tests that evaluate the amount of thyroid hormones, ultrasound, puncture, or thyroid biopsy, for example.Find out what tests are used in thyroid evaluation.
Thyroid scans can be done in just 1 day or in stages divided into 2 days and require a fast of at least 2 hours. When this is done in just 1 day, the radioactive substance technetium is used, which can be injected intravenously.to form images of the thyroid.
When the test is done in 2 days, on the first day, the patient takes iodine 123 or 131, in capsules or with straw, then thyroid images are obtained 2 hours and 24 hours after the start of the procedure.the patient can go out and do their normal daily activities and the test results are usually ready after about 3 to 5 days.
Iodine and technetium are used because they are substances that have a thyroid affinity and can focus more easily on this gland. In addition to the way of use, the difference between iodine or technetium use is that iodine is more appropriate for evaluating changes in thyroid function, such as hyperthyroidism or hypothyroidism.Technetium is very useful for identifying the presence of nodules.
Preparation for thyroid scans involves avoiding food, medications, and medical tests that contain or use iodine or affect thyroid function, such as:
Watch the video below and see which diet is best for iodine therapy
It is important to remember that pregnant or lactating women should not undergo thyroid scans; for technetium scans, breastfeeding should be discontinued for 2 days after the test.
The PCI- Complete Body Research test consists of a very similar examination, however, it is a used computer that generates images of the whole body, being particularly suitable in the case of metastases of tumors or thyroid cells in other parts of the body.Learn more about full body scanning here.