Thyroid And Parathyroid Ultrasound: What To Think About

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What To Think About

• A radioactive thyroid scan and radioactive iodine uptake (RAIU) test are nuclear medicine tests that use a radioactive substance to see how well the thyroid is working and identify thyroid problems. For more information, see the medical test Thyroid Scan.
• A thyroid ultrasound does not use a radioactive substance; it is easier to perform and is less expensive than a radioactive thyroid scan or RAIU test. But a thyroid ultrasound does not provide information about how well the thyroid gland is working.
• A thyroid ultrasound may be done at the same time as an RAIU test. RAIU testing is used more often than a thyroid ultrasound to identify problems such as hyperthyroidism. A thyroid ultrasound can be used to identify different types of thyroid problems, especially problems such as thyroid nodules.
• Thyroid nodules are common, especially in women and older people.
• Thyroid ultrasound can usually show the difference between a cyst, a solid nodule, or another type of mass that needs further testing. A fluid-filled sac that is smooth and round and that does not have any particles floating in it is likely to be a simple cyst. A lump that does not have any fluid or that has fluid with floating particles needs to be checked more closely. If a solid nodule is found, a thyroid biopsy may be needed.

Last updated:	June 11, 2008
Author:	Bets Davis, MFA
Reviewed By:	Caroline S. Rhoads, MD - Internal Medicine, Matthew I. Kim, MD - Endocrinology & Metabolism
Editors:	Maria Essig, Tracy Landauer