Reasons you may not be able to have the test or why the results may not be helpful include:
Not being able to hold still during the procedure. Movement can interfere with the quality of the ultrasound picture.
Having an open wound in the area that needs to be viewed.
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 topic 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.
Other Works Consulted
Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby.
ByHealthwise Staff Primary Medical ReviewerE. Gregory Thompson, MD - Internal Medicine Specialist Medical ReviewerMatthew I. Kim, MD - Endocrinology