How It Feels

The gel may feel cold when it is applied to your neck. Keeping your neck extended during the test may be uncomfortable, but you should not feel discomfort from the transducer or sound waves. You will be able to breathe and swallow normally during the test, and you will not hear the sound waves.

Risks

There is very little chance of a problem from a thyroid or parathyroid ultrasound test.

A thyroid ultrasound test does not use radiation, so it is safe to use during pregnancy and will not harm your growing baby.

Results

A thyroid and parathyroid ultrasound is an imaging test to check the thyroid gland and parathyroid glands. The results of a thyroid or parathyroid ultrasound test are usually available within 2 to 3 days.

What Affects the Test

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.