Thyroid and Parathyroid Ultrasound
A thyroid and parathyroid ultrasound is an imaging test to check the thyroid gland and parathyroid glands . A thyroid ultrasound can help measure the size and shape of the thyroid gland, but it cannot tell how well the thyroid gland is working. Ultrasound also may be used to check the four parathyroid glands that lie behind or next to the thyroid.
The thyroid gland makes a hormone called thyroxine that controls how fast the body converts food into energy (metabolism). Parathyroid hormone (PTH) is made by the parathyroid glands and controls the amount of calcium and phosphorus in the blood.
During a thyroid and parathyroid ultrasound, a small handheld instrument called a transducer is passed back and forth over the neck to form a picture of the thyroid gland and parathyroid glands.
Why It Is Done
A thyroid and parathyroid ultrasound is done to:
- Check lumps (thyroid nodule ) in the thyroid gland. A thyroid ultrasound can usually show the difference between a solid thyroid gland nodule and a simple fluid-filled sac (cyst).
- Find out whether the thyroid gland is enlarged. A thyroid ultrasound may also be used to keep track of the size of the thyroid gland during treatment for a thyroid problem.
- Look for enlarged parathyroid glands caused by disease. Normal parathyroid glands are often difficult to see on ultrasound and cannot be felt during physical examination. But abnormal parathyroid glands may be enlarged and easily seen by ultrasound.
- Guide the placement of the needle during a thyroid biopsy.
How To Prepare
No special preparation is required before having this test. You will need to remove jewelry from your head or neck before the test.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results may mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).
How It Is Done
A thyroid and parathyroid ultrasound is usually done by a radiologist or by an ultrasound technologist. It is done in an ultrasound room in a doctor's office or hospital.