is the test?
- There are two types
of thyroid nuclear medicine tests. Both assess the health of
your thyroid, a gland in your neck that controls metabolism.
A thyroid scan produces a picture of the gland to help evaluate
any lumps or inflammation, or to investigate the cause of an
overactive thyroid. A radioactive iodine uptake test is performed
to see if your thyroid is functioning normally and to determine
why thyroid hormone levels may be elevated. For both types
of test, a small amount of a weakly radioactive substance,
known as a radionuclide, is either injected into a vein or
given to you as a pill
- A thyroid scan is
usually ordered when a physical examination or laboratory finding
suggests that the thyroid is enlarged. If laboratory tests
show an overactive thyroid, a radioactive iodine uptake test
may be ordered at the same time.
- a radioactive iodine
uptake test measures the amount of radioactivity in your thyroid
after you've been given a relatively small dose of radioactive
iodine in pill form.Your thyroid gland absorbs iodine and uses
it to make hormones. Therefore, the amount of radioactive iodine
detected in your thyroid gland corresponds with the amount
of hormone your thyroid is producing.