Thyroid Ultrasound: Purpose, Procedure, Preparation & Results

The thyroid gland, shaped like a butterfly, sits at the front of the neck, just below the collarbone. It is vital to the endocrine system, as it produces thyroid hormones that manage metabolism, heart rate, and other body functions.

Thyroid problems may show you symptoms of fatigue and weight variations; however, finding the diagnosis can be tough. Sometimes imaging methods can provide results but at the same time radiate risks.

An ultrasound of the thyroid is a painless procedure that poses no risk of radiation while offering precise imaging of your thyroid, enabling accurate diagnosis of things like nodules and cancer. 

What is an ultrasound of the thyroid?

An ultrasound of the thyroid is an imaging test performed to evaluate the anatomy of your thyroid gland in the neck region. This test employs imaging through the use of ultrasound waves of high frequency.

Unlike X-rays, CT scans, and other such imaging methods, ultrasound is safer because it uses no radiation, and it is non-invasive, quick, and painless.

During a thyroid ultrasound procedure, a small device, known as a transducer, is placed on your neck over the thyroid. This device emits sound waves that strike against your thyroid and adjacent structures such as blood vessels and lymph tissues.

The transducer receives the echoing sound waves and transforms them into pictures by sending them to the computer.

These ultrasound images help your doctors assess the size, shape, and any abnormalities in your thyroid, such as nodules or cysts.

Such ultrasounds are part of the evaluation process if your doctor suspects that you may have thyroid disorders such as cancer, goitre, or benign thyroid nodules. While many thyroid nodules are harmless, ultrasounds can spot those needing surgery.

It helps your doctor to diagnose your thyroid conditions, as it can detect even small, often asymptomatic issues that may otherwise go unnoticed.

Why would you need a thyroid ultrasound?

A thyroid ultrasound may be recommended if:

• You have symptoms of thyroid problems, such as a noticeable lump or swelling in the neck, unexplained weight changes, or fatigue.

• Your doctor has felt a lump or abnormality during a physical exam of the thyroid.

• You have a history of thyroid disease or have been diagnosed with thyroid nodules.

• You need further evaluation after blood tests that indicate possible thyroid dysfunction (such as abnormal TSH levels).

• Your doctor needs to determine if a neck lump originates from the thyroid or adjacent structures.

• Your doctor has noticed some unusual swelling, pain, or signs of infection; they want to help figure out what might be causing these symptoms.

To take charge of your health, book an appointment with Thomson Medical to meet our medical specialists and discuss a personalised treatment plan.

How should you prepare?

No special preparation is needed for a thyroid ultrasound imaging exam.

• Clothing:

  • Wear loose, comfortable attire that allows straightforward access to your neck area, as the procedure focuses on your thyroid.

• No need to fast:

  • Unlike some other imaging procedures, you do not need to fast before a thyroid ultrasound.

• Avoid lotions or oils:

  • Do not apply lotions or oils on your neck on the day of your thyroid scan, as these substances can interfere with sound wave transmission and potentially affect image quality.

• Avoid wearing jewellery:

  • You will need to remove jewellery, such as necklaces or pendants, before the test begins.

How does the procedure work?

An ultrasound of the thyroid is painless and typically takes around 15 to 30 minutes. The procedure involves the following:

• Gel application:

  • A technician applies a special gel to the skin on your neck. This gel helps sound waves travel smoothly between the transducer and your body.

• Transducer placement:

  • A small, hand-held instrument called a transducer is moved over your neck area. It sends out high-frequency sound waves and receives the echoes that bounce back from the thyroid and surrounding tissues.

• Imaging:

  • These echoes are converted into images by a computer, which are displayed on a monitor. The images provide detailed views of your thyroid gland and nearby structures.

The gel ensures optimal sound wave transmission, allowing for clear and accurate imaging. The computer analyses the sound waves based on their amplitude, frequency, and travel time to create precise images of your thyroid gland and its structures.

How does ultrasound imaging work?

Ultrasound imaging operates on the same principles as sonar technology used by bats, ships, and fishermen.

When sound waves encounter an object, they bounce back or echo. By analysing these echo waves, it is possible to determine the object's distance, size, shape, and consistency, including whether it's solid or fluid-filled.

In a medical context, ultrasound helps doctors identify changes in organs, tissues, and vessels and detect abnormal masses like tumors. Here's how it works:

• Transducer Function:

  • A transducer sends high-frequency sound waves into your body and records the returning echoes. When pressed against the skin, it emits pulses of sound waves that bounce off internal structures.

• Image Creation:

  • The transducer captures changes in the sound's pitch and direction as it reflects off internal organs, fluids, and tissues. A computer processes these echoes and displays them as real-time images on a monitor. The technologist can capture still images or save video loops for further analysis.

What will you experience during and after the procedure?

During the procedure

You will lie on an exam table for the ultrasound test. A technician will apply a gel to your neck and move a transducer over the area. You might feel a slight pressure as the device moves, but it should not be painful.

After the Procedure

There are no after-effects or recovery time required. You can immediately resume your normal activities without any restrictions. The examination process is quick and straightforward, allowing you to continue with your day as usual after the ultrasound test.

Understanding thyroid ultrasound results

The ultrasound thyroid test provides valuable information about your thyroid’s health.

The results can help identify:

• Normal thyroid size and shape:

  • Confirming that the thyroid is functioning properly.

• Thyroid nodules or cysts:

  • These are common and are usually benign, but they may require further evaluation or monitoring.

• Changes in the thyroid tissue:

  • The ultrasound can also detect changes in the thyroid tissue, such as inflammation or scarring.

• Suspicious features:

  • Nodules with irregular edges may suggest a higher risk of malignancy, necessitating a biopsy or additional testing. While many nodules are benign, further assessment is crucial for accurate diagnosis, often complemented by thyroid function tests.

The results from a thyroid ultrasound are important for your doctor to determine the best course of action, ensuring accurate diagnosis and timely treatment if needed.

Benefits and risks of ultrasound for patients

Benefits

• Non-Invasive:

  • Ultrasound exams are gentle and do not involve needles or injections, making them a stress-free experience.

• Accessibility and Cost:

  • Ultrasound technology is widely available and generally less expensive than other imaging methods like MRI or CT scans.

• Safety:

  • Ultrasound does not use radiation, making it a safe choice for patients of all ages, including pregnant women.

• Clear Imaging:

  • It provides excellent views of soft tissues, which are not as visible with X-rays.

• Real-Time Imaging:

  • This feature allows doctors to guide procedures like needle biopsy in real-time, enhancing accuracy.

Risks

• Minimal Discomfort:

  • While most ultrasounds are painless, you might feel slight discomfort if the transducer is pressed firmly on sensitive areas.

• Generally Safe:

  • Diagnostic ultrasounds have no known harmful effects on humans. However, it's essential to follow medical guidelines and avoid unnecessary prolonged exposure to ensure safety.

FAQ

What does a thyroid ultrasound tell you?

A thyroid ultrasound provides detailed information about the size, shape, and texture of your thyroid gland. It can detect the presence of nodules, cysts, inflammation, or other abnormalities that might require further investigation or treatment.

Will a thyroid ultrasound show cancer?

A thyroid ultrasound can help identify suspicious nodules that might be cancerous, but it cannot definitively diagnose cancer. If a nodule has certain characteristics (such as irregular borders or solid composition), the doctor may recommend a fine needle aspiration (FNA) biopsy to test the tissue for cancer.

What is the benefit of a thyroid ultrasound?

The primary benefits of a thyroid ultrasound are:

• Non-invasive:

  • It’s a safe, non-painful procedure.

• Identifies abnormalities:

  • It can detect thyroid nodules, cysts, or growths early.

• Guides treatment:

  • It helps your doctor decide whether further tests or treatments, like a biopsy, are necessary.

• Monitors thyroid conditions:

  • It can help monitor changes in nodules or other thyroid issues over time.

What are red flags on thyroid ultrasound?

Certain features on a thyroid ultrasound can raise concerns:

• Irregular borders around a nodule.

• Tiny calcium deposits within a nodule (microcalcifications).

• Increased blood flow within a nodule.

• If the nodule or gland has uneven tissue patterns (heterogeneous texture). These features may indicate a higher likelihood of malignancy, and further testing or biopsy might be recommended.

How do I know if my thyroid ultrasound is normal?

A normal thyroid ultrasound will show:

• A normal-sized thyroid with no lumps, cysts, or abnormalities.

• Homogeneous texture, meaning the tissue looks even and smooth.

• No signs of abnormal growth or inflammation.

Can an ultrasound confirm cancer?

A thyroid ultrasound can suggest cancer by identifying suspicious nodules, but it cannot confirm cancer. If a nodule looks concerning (e.g., irregular shape, firm texture), your doctor may recommend a biopsy (such as a fine needle aspiration) to definitively determine if the nodule is cancerous.

The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations based on your medical conditions, request an appointment with Thomson Medical.