At a glance
A thyroid scan is a nuclear medicine imaging test that uses a small amount of radioactive material to create a picture of the thyroid gland, the butterfly-shaped gland at the front of your neck that controls metabolism and energy levels.
You swallow or receive an injection of a radiotracer (a mildly radioactive substance). The thyroid absorbs this substance just as it would normally absorb iodine from food. A camera called a gamma camera then detects the radiation coming from the gland and turns it into an image. Areas that absorb more radiotracer appear brighter on the image and are called "hot spots"; areas that absorb less appear darker and are called "cold spots". This pattern tells the doctor how different parts of the gland are functioning.
Medical Condition
A thyroid scan is ordered when a doctor needs to understand not just the size or shape of the thyroid, but how well it is actually working. It is most often used alongside a blood test called TSH (thyroid-stimulating hormone) to get a complete picture.
- A nodule (lump) found in the thyroid on ultrasound, to check whether it is active or inactive.
- Hyperthyroidism (an overactive thyroid) to find out whether the whole gland or only a part of it is overproducing hormones.
- Graves' disease, an autoimmune condition that causes the thyroid to overproduce hormones.
- A toxic adenoma or toxic multinodular goitre (one or more lumps producing excess hormones independently).
- Monitoring thyroid cancer after surgery or radioiodine treatment, to check whether cancer cells remain.
- Unexplained swelling at the front of the neck to determine whether thyroid tissue is involved.
- Locating thyroid tissue that may have moved to an unusual position in the chest or behind the breastbone.
The scan is not suitable for everyone. Doctors generally avoid it in the following situations.
- Pregnancy, because the radiotracer can reach the developing baby.
- Breastfeeding, unless the mother is willing to stop feeding for a period your doctor specifies.
- Recent exposure to large amounts of iodine (for example, from a CT scan contrast dye or certain medications), which can block the tracer from being absorbed properly.
- Known allergy to the radiotracer being used.
Risks & Complications
A thyroid scan carries very low risk. The radiation dose is small, comparable to background radiation from everyday life, and the radiotracer leaves the body within hours to a couple of days.
- Mild discomfort or bruising at the injection site, if an injection is used rather than a capsule or liquid.
- A slight metallic or unusual taste, reported by some patients after receiving the radiotracer.
- Allergic reaction to the radiotracer, which is rare. Staff are trained to manage this if it occurs.
- Very low-level radiation exposure. The dose used is carefully chosen to be the minimum needed to produce a clear image.
- Temporary need to avoid close, prolonged contact with pregnant women and young children for the hours after the test, because the body is still releasing a small amount of radiation.
Preparation & Procedure
Preparation for a thyroid scan differs depending on which radiotracer the hospital uses. Your doctor or the nuclear medicine department will give you specific instructions when you book the appointment.
Common steps before the scan include stopping certain medications. Thyroid hormone replacements, thyroid-blocking drugs, and multivitamins containing iodine are usually paused for days to weeks beforehand. Some hospitals ask patients to follow a low-iodine diet (avoiding seafood, seaweed, iodised salt, and dairy) for one to two weeks before the scan. Confirm the exact duration with your care team.
Contrast dyes used in CT scans can interfere with the radiotracer. If you had a CT with contrast recently, tell your doctor so they can decide the right timing. You do not usually need to fast from food or water for a standard thyroid scan, but your team will confirm this.
Tests that may be done before or on the day of the scan include blood tests for TSH and thyroid hormone levels, and often an ultrasound to map the size and shape of the gland before the imaging begins.
On the day of the scan, the procedure usually follows these steps.
- You arrive at the nuclear medicine department and the team reviews your medications and recent iodine exposure.
- The radiotracer is given, either as a capsule or liquid you swallow, or as an injection into a vein in your arm.
- You wait for the radiotracer to be absorbed by the thyroid. This waiting period is usually several hours for one type of tracer and may be up to 24 hours for a radioiodine tracer.
- You lie still on a padded table. The gamma camera moves slowly around your neck.
- The scan itself takes roughly 20 to 30 minutes in most centres, though your team will confirm the expected duration.
- The radiologist or nuclear medicine specialist reviews the images, sometimes while you are still present, and may take additional pictures if needed.
- You are free to leave once the team confirms the images are clear.
Aftercare
Recovery after a thyroid scan is straightforward because no surgery or sedation is involved. Most patients feel completely normal immediately after the images are taken and can drive and eat as usual.
- Drink plenty of water for the rest of the day. This helps flush the radiotracer from your body through urine more quickly.
- Flush the toilet twice after using it for the first day or two, as a simple precaution while small amounts of radiotracer are still leaving the body.
- Avoid prolonged close contact with pregnant women, infants, and young children for the number of hours your care team specifies, usually 6 to 24 hours depending on the tracer used.
- If you stopped thyroid medications before the scan, ask your care team exactly when to restart them. Do not restart on your own without guidance.
- A follow-up appointment is usually arranged within one to two weeks to discuss the scan results alongside your blood test findings.
- If the scan was done to investigate a thyroid nodule or suspected cancer, further tests such as a fine-needle biopsy (a thin needle used to take a small tissue sample) may be recommended based on the results.
Cost & What Determines It
The cost of a thyroid scan varies considerably depending on where it is done and what the clinical situation requires. Nuclear medicine services involve specialised equipment, licensed radioactive materials, and trained radiopharmacists, all of which affect the final price differently from one country or hospital to the next.
- Type of radiotracer used. Technetium-based tracers and radioiodine have different costs, and some clinical situations require one over the other.
- Hospital class. A university hospital with a full nuclear medicine department will price this differently from a private specialist clinic.
- Country where the scan is performed. Regulatory costs for handling radioactive materials, staff wages, and equipment maintenance vary widely across countries.
- Whether blood tests and ultrasound are bundled into the same visit or billed separately.
- Whether the scan is a single standard image or whether additional views, SPECT (single-photon emission computed tomography, a 3D version of the scan), or a combined SPECT/CT are needed.
- Consultation fees for the nuclear medicine specialist who prescribes and interprets the scan.
- Any pre-scan medications required to prepare the thyroid, such as drugs to temporarily suppress thyroid function before a whole-body scan for cancer surveillance.
Hospital packages sometimes bundle the consultation, the radiotracer, the scan itself, and a written report into one price. Items that are commonly billed separately include blood tests, ultrasound, additional specialist consultations, and any follow-up procedures recommended after the results come in.
BPJS Kesehatan does not cover medical procedures performed outside Indonesia, and most Indonesian private health insurance plans do not either. Patients who travel abroad for a thyroid scan typically pay out of pocket or through an international private health insurance plan that explicitly covers overseas care. Before you travel, ask the hospital for a written cost estimate that lists each item individually. This makes it easier to compare options and to submit a claim to your insurer if you have one.
Frequently Asked Questions
Does a thyroid scan hurt?
A thyroid scan is not painful. A small amount of radioactive tracer is given either as a drink or an injection, and after a waiting period you simply lie still while a special camera takes images of your thyroid gland, the butterfly-shaped gland in your neck. Most people find the procedure no more uncomfortable than lying on an exam table.
How do I prepare for a thyroid scan, and do I need to fast?
Your doctor will usually ask you to stop taking certain thyroid medications and supplements for a period before the scan, because they can affect how the tracer is absorbed. Fasting requirements vary depending on the type of tracer used, so follow the specific instructions your nuclear medicine team gives you. Tell your doctor about all medications you take and mention if you have had any iodine-based contrast dye recently, as this can also interfere with the results.
How long does a thyroid scan take?
The actual imaging usually takes between 20 and 45 minutes, but your total time at the facility will be longer. After receiving the tracer, you typically wait several hours, sometimes up to 24 hours, for it to be absorbed by the thyroid before the camera scan begins. Your nuclear medicine team will tell you exactly when to return for imaging.
How much does a thyroid scan cost?
The cost of a thyroid scan depends on the type of tracer used, the hospital or clinic class, and whether additional imaging views are requested by your doctor. Because these factors vary from one facility to another, the most reliable way to know what you will pay is to request a written cost estimate from the hospital before your appointment.
This page is general information, not a substitute for medical advice. Every case is different. Your doctor decides what is right for you.
