Medical Imaging

Nuclear Medicine > Exams & Procedures > Thyroid Scan

This test determines the size, shape and position of your thyroid gland. It also detects lumps and bumps in the thyroid gland.

This test involves the injection of a radioactive tracer that will flow through the bloodstream and be picked up by the thyroid gland. Pictures will be taken as the tracer is injected and for a few minutes afterwards from different angles.

Preparation

  • This test is often requested in combination with a thyroid uptake, which determines the level of activity of your thyroid gland (overactive hyperthyroid or underactive hypothyroid). The thyroid uptake is a two-day test, each visit taking about 20 minutes. When ordered in combination, the thyroid scan is performed after the second uptake visit.
  • You should have no X-ray tests that use an iodine-based contrast dye within two to four weeks of this test.
  • Bring a list of all medications and supplements you take. This includes vitamins, herbal remedies, and holistic medications.
  • Do not bring children or pregnant women with you to the department. We do not want to expose them to unnecessary radiation.
  • Any of these procedures is subject to change according to the nuclear medicine physician. The duration of the tests is a rough estimate. Please be aware that the time may be lengthened if a scan has to be repeated, if emergency cases are brought to the department or due to unforeseen circumstances.

About the Procedure

  • The procedure takes about 20 to 30 minutes for the thyroid scan only.
  • A technologist will briefly explain the test to you and try to answer any questions you may have about the procedure.
  • You will be interviewed about your thyroid condition, your medications, and any signs and symptoms you may be experiencing.
  • You will be asked to lie down on an imaging bed.
  • A camera will be positioned above you.
  • The technologist will give you an injection of a radioactive tracer into a vein.
  • Pictures will be taken as the tracer is injected.
  • More pictures will be taken from different angles around your thyroid gland.