Thyroid Scan



  1. Evaluation of goitre and nodules.

  2. Evaluation of hyperthyroidism.


  • Pertechnetate is avidly trapped in the thyroid gland.

Preparation and Procedure:

  • No thyroid hormone for 6 weeks prior to the scan, a patient can be scanned if they have been on thyroxine for 5 days or less.

  • The patient should not have had iodine based x-ray contrast 4 weeks prior to the scan.

  • If the patient is on Amioderone, refer to Thyroid physician.

  • The scan takes 10 minutes to complete. The entire procedure takes about 30 minutes.


Thyroid scanning is a well established test for evaluating many thyroid diseases. The scan helps to classify the goitre into diffuse or multinodular goitres. Thyroid nodules can be classified into those that concentrate tracer (hot nodules) and those that do not (cold nodules). Distortions and extensions of the gland beneath the sternum can be seen. The thyroid scan aids in the evaluation of hyperthyroidism by demonstrating findings that differentiate Graves' disease, toxic adenoma, toxic multinodular goitre and thyroiditis.


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Page last reviewed: 16 January 2015