Thyroid ultrasound is the best and most common method for evaluating the thyroid. This imaging test uses sound waves to get pictures of the thyroid gland, surrounding tissue and structures, and the lymph nodes in the neck. The first imaging study used in work-up and evaluation of thyroid cancer and thyroid problems should always be an expert, skilled, dedicated thyroid and neck ultrasound. Finally, if a needle biopsy (or fine-needle aspiration biopsy) is necessary to diagnose thyroid cancer, an ultrasound is used to guide the needle into the thyroid nodule or lymph node in order to obtain an accurate and safe biopsy.

Here are 4 things you need to know about thyroid ultrasound

#1 Thing to Know about Thyroid Ultrasound: No radiation

Simply put, an ultrasound exposes the patient to absolutely no radiation. Unlike a CT scan or x-ray study, ultrasound does not use radiation to obtain pictures of the inside of your body. Ultrasound uses harmless sound waves. When a patient needs imaging to evaluate their thyroid for nodules, cancer, or other thyroid conditions, an ultrasound of the neck is ordered. Ultrasound uses sound waves to create pictures inside your neck that allow for evaluation of the thyroid gland, structures nearby (windpipe, esophagus, blood vessels, etc.), and lymph nodes.

During your ultrasound of the neck and thyroid, a small, wand-like instrument called a transducer is placed on the skin in front of your thyroid gland. This transducer gives off sound waves and picks up the echoes as they bounce off the thyroid (and other underlying neck structures). The echoes are converted by a computer into a black and white image on a computer screen. The resolution, or ability of the machine to obtain crisp, clear pictures of even microscopic nodules or lumps in the thyroid, is very important. Again, you are not exposed to any radiation during this test. Below is a picture of a high-resolution ultrasound machine.

Learn more about how ultrasound is used to diagnose thyroid and parathyroid disease.

#2 Thing to Know about Thyroid Ultrasound: Best imaging method for evaluating thyroid

As noted above, thyroid ultrasound is the best imaging method to evaluate the thyroid. This includes work-up and diagnosis of thyroid nodules, cancer, and other thyroid disease. When someone is diagnosed with a thyroid condition, they should have a skilled, thorough ultrasound done if one has not been performed. If your doctor first orders a CT scan, MRI, or PET/CT scan to evaluate your thyroid problems, you need a second opinion from an expert.

Thyroid ultrasound can help determine if a thyroid nodule is solid or filled with fluid. (Solid nodules are more likely to be cancerous.) This test can also be used to check the number and size of thyroid nodules and can even reveal what the blood supply looks like to these nodules. Additionally, this method is excellent to look for thyroid cancer that has spread to lymph nodes in the neck. Furthermore, ultrasound is used to perform needle biopsies of thyroid lumps and lymph nodes to see if they are cancerous or not.

Figure 1: Ultrasound image of a cancerous thyroid nodule

Figures 2 & 3: Ultrasound images of multiple enlarged, cancerous lymph nodes with a speckled, irregular appearance in the left side of the neck.

Learn more about ultrasound and the diagnosis of thyroid cancer.

#3 Thing to Know about Thyroid Ultrasound: Need to examine lymph nodes in the neck

You should feel good knowing a thyroid ultrasound was the first imaging test ordered by your doctor to examine and diagnose any masses or problems in your thyroid gland. If you do not get a skilled, expert ultrasound done with a high-resolution ultrasound machine, however, you run the risk that some thyroid problems, particularly thyroid cancer, might be missed. Every thyroid ultrasound must include examination of the lymph nodes and the tissues that surround the thyroid. This should be done in the middle of the neck, and on both sides of the neck, from the jaw down to the sternum and collarbone. Otherwise, thyroid cancer that has spread will be missed. Thus, the goal of the thyroid ultrasound is NOT just to look at the thyroid. A high-quality thyroid ultrasound also examines all the tissues on both sides of the neck to look for enlarged or abnormal- appearing lymph nodes.

High- resolution ultrasound has a detection capability as small as 1-2 mm (the size of a tip of a ball point pen) for a thyroid cancer or thyroid cancer that has spread to lymph nodes. An excellent, thorough ultrasound will determine if thyroid cancer is present or if a needle biopsy needs to be performed to diagnose thyroid cancer or spread to the lymph nodes. The only weakness of ultrasound is that it cannot distinguish cancerous from inflammatory or reactive lymph nodes. Both can have very similar appearances, but ultrasound- guided FNA will provide the necessary microscopic ability to confirm or rule out a diagnosis of papillary thyroid cancer.

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#4 Thing to Know about Thyroid Ultrasound: Expert ultrasound team is crucial

Ultimately, the quality of the ultrasound is dependent upon four factors. Each factor is critically important and listed below.

• The quality of the ultrasound machine
• The device that is held in the hand of the technician (the transducer) producing the sound waves
• The experience and the skill of the ultrasound technician
• The experience of the surgeon or radiologist who is interpreting the study.

The best thyroid ultrasounds are done by experts who perform many on a daily basis. Your ultrasound should be performed by someone who is specifically dedicated to the ultrasound examination of the thyroid and neck. Experience means everything when you are considering the sensitivity and accuracy of a neck ultrasound. At our thyroid center, the ultrasound technicians only perform ultrasounds of the thyroid and neck every day.

You can’t diagnose what you cannot see or find. You also need to know what you are looking at to properly diagnose thyroid cancer and thyroid disease. This expertise only comes with tens of thousands of ultrasounds and thorough evaluation/reading of the ultrasound pictures. Settling for anything less than a highly-experienced and adept ultrasound team can be detrimental to your health.

Summary

Ultrasound is the first and most critical imaging test for thyroid cancer and thyroid problems. This test exposes the patient to no radiation. A thorough ultrasound looking at the thyroid and the entire neck is paramount to ensure thyroid cancer is not missed. Experience and expertise mean everything when you are considering where to have your thyroid ultrasound and evaluation done. Entrust only the best with your thyroid health.

To learn more and become a patient, see our resources below.

Additional Resources

• Become our patient by filling out the form at this link. 
• Learn more  The Clayman Thyroid Center here. 
• Learn more about our sister surgeons at the Scarless Thyroid Surgery Center, Norman Parathyroid Center, and Carling Adrenal Center
• Learn more about the Hospital for Endocrine Surgery.