Test Overview
A thyroid scan uses a
radioactive tracer and a special camera to measure how much tracer the
thyroid
gland
absorbs from the blood. A thyroid scan is done to find problems with the
thyroid gland. A thyroid scan may be done to check for
thyroid nodules, or it may be done with a
radioactive iodine uptake test (RAIU) to check how well the thyroid gland is working.
A thyroid scan can show the size, shape, and location of the
thyroid gland. It can also find areas of the thyroid gland that are
overactive or underactive. The camera takes pictures of the thyroid
gland from three different angles. The radioactive tracer used in this test is
either iodine or technetium.
Another type of thyroid scan, a whole-body thyroid scan, may be
done for people who have had thyroid cancer that has been treated. The whole-body scan can check to see if cancer has spread to other areas of the body.