Thyroid Scan

A Thyroid Scan is a nuclear medicine procedure providing information about the function and structure of the thyroid gland, which is responsible for processing and adjusting certain hormones in the body. A Thyroid Scan can determine if the thyroid gland is over-active or under-active and can distinguish between benign and malignant thyroid nodules.


  • Prior to a Thyroid Scan, a patient should consult their doctor about the need to cease existing medications, foods, vitamin supplements that can affect the quality of the scan (for example, cough medicine, Betadine, Fish Oil Tablets and Kelp).
  • If a patient has had radiology procedure requiring the injection of a contrast medium within four weeks prior to the scheduled Thyroid Scan, then the patient will need to rebook the scan for a later date.
  • Patients must bring their request/referral form on the day (or check that their request/referral is at the practice)
  • Notify Lakes Radiology team of any allergies, existing medications and if there is a chance you could be pregnant
  • Patients should inform the receptionist when booking the procedure if you are breast feeding as alternate arrangements may need to be made (ie you may need to stop breast feeding for a short time).


  • A medical practitioner/technician will talk to you prior to the test and will provide ample opportunity to answer questions you may have at this time.
  • A cannula will be inserted into the arm so that a radiopharmaceutical called ‘sodium pertechnetate’ will be injected.
  • The patient will wait 15-20 minutes for the radioactive substance to concentrate in the thyroid gland.
  • The patient will be placed on a scanning bed with a gamma ray camera positioned close to their head.
  • Several images will be taken, with the camera placed at different angles when taking the images.
  • At the completion of the study, the radiologist will check the quality of the images to ensure optimal diagnostic study has been performed.
  • The patient should contact their referring doctor for the result of the test.

Risks or Side Effects

  • There are minimal risks with a Thyroid Scan using Nuclear Medicine Imaging.
  • Exposure to radiation is similar to that received during a routine diagnostic x-ray.
  • There is a risk of allergic reaction to the radiopharmaceutical or diuretic however these are rare and usually minor. If there is an allergic reaction, the patient will be monitored carefully to ensure any reaction is treated appropriately.

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