A thyroid scan uses a Reference radioactive tracer Opens New Window and a special camera to measure how much tracer the thyroid gland absorbs from the blood. The tracer can be swallowed or can be injected into a vein. It travels through your body, giving off radiation signals. The camera "sees" the signals and can measure how much tracer the thyroid absorbs from the blood.
A thyroid scan can show the size, shape, and location of the Reference thyroid gland Opens New Window Reference Opens New Window. 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.
A radioactive iodine uptake (RAIU) test may also be done to find problems with how the thyroid gland works, such as Reference hyperthyroidism Opens New Window. For more information, see the medical test Reference Radioactive Iodine Uptake Test.
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.
|By:||Reference Healthwise Staff||Last Revised: Reference May 31, 2011|
|Medical Review:||Reference E. Gregory Thompson, MD - Internal Medicine
Reference Matthew I. Kim, MD - Endocrinology