Day of Scan Do not eat for 2 hours before your appointment. You may drink water.
Q. How is a nuclear thyroid scan done?
A nuclear medicine thyroid scan uses a radioactive medication (radiopharmaceutical) to take pictures or images of the thyroid gland. The radiopharmaceutical is injected into a vein, usually in the arm, and enters the thyroid gland from the circulating blood.
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Q. How long does a thyroid nuclear scan take?
Actual scanning time for a thyroid scan is 30 minutes or less. You will be given radioactive iodine (I-123 or I-131) in liquid or capsule form to swallow. The thyroid uptake will begin several hours to 24 hours later.
Q. What can I expect from a thyroid uptake scan?
During Your Exam On your first visit, you will swallow a small radioactive iodine capsule. On your second visit (four hours after taking the capsule), you will have an uptake measurement, pictures of your thyroid gland and an examination of your thyroid gland by the nuclear medicine physician.
Q. Is thyroid scan painful?
You may experience mild pain and redness at the injection site for a short time if you receive an injection of the radionuclide. Even though the radiation exposure is minimal and short term, thyroid scans aren’t recommended for pregnant or breastfeeding women.
Q. What is the normal range for thyroid uptake?
The normal values of thyroid uptake of radiotracer are 3 to 16% at 6 hours and 8 to 25% at 24 hours. These values may change according to laboratory standard techniques or patient dietary habits. The thyroid gland can uptake more or less than normal.
Q. What are early warning signs of hyperthyroid problems?
Symptoms
- Unintentional weight loss, even when your appetite and food intake stay the same or increase.
- Rapid heartbeat (tachycardia) — commonly more than 100 beats a minute.
- Irregular heartbeat (arrhythmia)
- Pounding of your heart (palpitations)
- Increased appetite.
- Nervousness, anxiety and irritability.
