Thyroid Scan

A thyroid scan gives qualitative information on the functioning of the thyroid glands. It can be used in conjunction with thyroid function blood tests.

Indications

A thyroid scan gives the doctor a better picture of what the problem might be affecting your thyroid glands. It makes the doctor's decision of what treatment method to use, less difficult. Some reasons for requesting a thyroid scan are:

To gather information on a goitre.

To gather information on a nodule in one of the lobes.

To determine whether swelling in the neck is being caused by the thyroid gland.

To determine the effectiveness of treatment.

To follow up on abnormal blood test results.

To determine the cause of hyperthyroidism.

To check the body for secondaries of a primary thyroid cancer.

Isotopes

A thyroid scan is performed using either Technetium or Iodine. The procedure for the scan depends on the isotope used

Technetium: The tracer is injected intravenously and there is a waiting period of about twenty (20) minutes before scanning. Scanning takes about 20 to 30 minutes.

Iodine: Twenty four hours before the scan, an iodine capsule will be administered orally and the following day the scan is performed. This procedure involes preparation, instructions will be given by the doctor that must be followed in order for the scan to work.