Thyroid and parathyroid ultrasound

A thyroid and parathyroid ultrasound is done to:

• Check a lump (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 if the thyroid gland is too large. A thyroid ultrasound may also be used to keep track of the size of the thyroid gland during treatment for a thyroid problem.
• Guide the placement of the needle during a thyroid biopsy.
• Look for enlarged parathyroid glands caused by disease. Normal parathyroid glands are often hard to see on ultrasound. And they can't be felt during a physical exam. But abnormal parathyroid glands may be enlarged and easily seen by ultrasound.

This test is done in an ultrasound room in a doctor's office or hospital.

You may be asked to undress above the waist. And you may drape a paper or cloth covering around your shoulders. Remove all jewelry from your head and around your neck.

You will lie on your back on a high table with your neck stretched out. You'll have a pillow under your shoulders. Gel will be spread on your neck. This helps the sound waves pass through better. (They do not pass easily through air.) A small water-filled bag or gelatin sponge might be placed over your throat. This also helps to conduct the sound waves. The transducer will be pressed against your neck (or against the water-filled bag or gelatin sponge, if used). Then it will be moved back and forth over your neck. A picture of your thyroid gland and the tissue around it can be seen on a video screen. You may be asked to turn your head away from the side being scanned so your jawbone is out of the way.

You may be asked to wait until the radiologist has reviewed the information. He or she may want to do more ultrasound views of your neck.

In general, there's nothing you have to do before this test, unless your doctor tells you to.

The results of this test are usually ready in 2 to 3 days.