endocrine
Thyroid Nodule Ultrasound: What to Expect
A thyroid ultrasound is painless, radiation-free, and takes 15 to 30 minutes. It uses sound waves to create detailed images of the thyroid. Specific nodule features — size, composition, borders, echogenicity, and calcifications — are scored to determine whether you need a biopsy, repeat imaging, or no further workup.
What happens during a thyroid ultrasound?
You will lie on your back with your neck slightly extended. A sonographer or radiologist will apply clear gel to your neck and move a small handheld transducer (probe) over the skin above your thyroid. There is no pain, no radiation, and no injections in a standard thyroid ultrasound. The whole procedure typically takes 15 to 30 minutes.
Images are captured in real time, showing the size, location, and internal texture of the thyroid gland and any nodules within it 1Ref 1Haugen BR, Alexander EK, Bible KC, et al. (2016).2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer.Ultrasound feature assessment criteria, biopsy thresholds, surveillance intervals, and growth-based trigger for repeat biopsy in thyroid nodules.
Do I need to do anything to prepare?
No special preparation is required. You do not need to fast, and you can take your regular medications as normal. Wear a top that gives easy access to your neck — a scoop or V-neck, or something you can pull down slightly at the collar. No contrast dye or IV line is needed.
What do radiologists look for on a thyroid ultrasound?
Radiologists evaluate several features of each nodule to assign a risk level. The ACR TI-RADS scoring system, widely used since 2017, assigns points for 2Ref 2Tessler FN, Middleton WD, Grant EG, et al. (2017).ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee.TI-RADS scoring system: five feature categories (composition, echogenicity, shape, margin, echogenic foci), point-based risk levels TR1–TR5, biopsy size thresholds by level, and repeat-imaging intervals:
- Composition — whether the nodule is solid, cystic (fluid-filled), or mixed; spongiform nodules (sponge-like, mostly fluid) carry the lowest risk
- Echogenicity — how the nodule appears compared to surrounding thyroid tissue; hypoechoic (darker) nodules carry higher suspicion
- Shape — a nodule that is taller than it is wide is a higher-risk feature
- Margin — irregular, spiculated, or lobulated borders are associated with greater concern
- Echogenic foci — microcalcifications (tiny bright spots) and rim calcifications are higher-risk features; large comet-tail artifacts are reassuring
Points from each category are totaled to assign a TI-RADS level (TR1–TR5), which drives whether and at what size biopsy is recommended 2Ref 2Tessler FN, Middleton WD, Grant EG, et al. (2017).ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee.TI-RADS scoring system: five feature categories (composition, echogenicity, shape, margin, echogenic foci), point-based risk levels TR1–TR5, biopsy size thresholds by level, and repeat-imaging intervals.
When will I get the results?
The time to receive results varies by facility. In many practices, the radiologist generates a report within 24 to 72 hours, which is sent to the clinician who ordered the scan. You may be able to view the images and report through a patient portal before speaking with your clinician. The report will describe each nodule's features, its TI-RADS or equivalent risk category, and a specific recommendation — such as no further imaging, follow-up ultrasound at 12 to 24 months, or referral for biopsy 2Ref 2Tessler FN, Middleton WD, Grant EG, et al. (2017).ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee.TI-RADS scoring system: five feature categories (composition, echogenicity, shape, margin, echogenic foci), point-based risk levels TR1–TR5, biopsy size thresholds by level, and repeat-imaging intervals.
What happens if a nodule needs a biopsy?
If ultrasound features and size meet biopsy thresholds, a fine-needle aspiration (FNA) is the next step. This is a separate procedure, usually performed under ultrasound guidance by an endocrinologist or radiologist. A very thin needle is placed into the nodule to collect a small sample of cells for pathological review under the Bethesda classification system 3Ref 3Ali SZ, Baloch ZW, Cochand-Priollet B, Schmitt FC, Vielh P, VanderLaan PA (2023).The 2023 Bethesda System for Reporting Thyroid Cytopathology.Six-category Bethesda classification used to interpret FNA biopsy cell samples, with updated risk-of-malignancy estimates for each category. It takes about 20 to 30 minutes and is done outpatient — most people return to normal activities the same day.
How often will I need repeat thyroid ultrasounds?
Surveillance frequency depends on the nodule's risk level at initial imaging 1Ref 1Haugen BR, Alexander EK, Bible KC, et al. (2016).2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer.Ultrasound feature assessment criteria, biopsy thresholds, surveillance intervals, and growth-based trigger for repeat biopsy in thyroid nodules2Ref 2Tessler FN, Middleton WD, Grant EG, et al. (2017).ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee.TI-RADS scoring system: five feature categories (composition, echogenicity, shape, margin, echogenic foci), point-based risk levels TR1–TR5, biopsy size thresholds by level, and repeat-imaging intervals:
- Very low suspicion / spongiform nodules: no follow-up imaging may be needed if below 1 cm
- Low suspicion: follow-up ultrasound at 12 to 24 months
- Intermediate or high suspicion below biopsy threshold: follow-up at 12 months
- Benign on FNA: follow-up at 12 to 24 months, then less frequently if stable
If the nodule shows significant growth on surveillance — generally more than 20% increase in two dimensions with at least a 2 mm absolute increase — biopsy may be recommended even if prior results were benign 1Ref 1Haugen BR, Alexander EK, Bible KC, et al. (2016).2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer.Ultrasound feature assessment criteria, biopsy thresholds, surveillance intervals, and growth-based trigger for repeat biopsy in thyroid nodules.
Who interprets thyroid ultrasounds and who should I follow up with?
Radiology technologists perform the scan; radiologists interpret the images. For ongoing management of a thyroid nodule, an endocrinologist — a physician specializing in thyroid and hormonal conditions — typically takes over follow-up care. Your primary care clinician can coordinate this referral and will also receive the ultrasound report.
Gale can help you understand the language of your ultrasound report and prepare questions for your endocrinology visit.
Common questions
Is a thyroid ultrasound the same as a thyroid scan?
No. A thyroid ultrasound uses sound waves to show the structure of the gland and identify nodules. A thyroid scan (scintigraphy) uses a radioactive tracer to show which parts of the gland are functionally active (hot) or inactive (cold). Ultrasound is the first-line imaging for nodule evaluation; a scan is sometimes ordered afterward when a biopsy result is indeterminate or when functional activity is in question.
Can a thyroid ultrasound tell me if a nodule is cancerous?
Ultrasound can identify features associated with higher or lower risk but cannot definitively diagnose cancer. Only a biopsy with pathological review of the cells — reported using the Bethesda System — can confirm or rule out malignancy. Ultrasound determines whether biopsy is warranted.
What if my nodule is too small to biopsy?
Nodules below biopsy size thresholds are monitored with periodic ultrasounds. Most grow very slowly or not at all, and the majority of small nodules — even those with some suspicious features — turn out to be benign over time. The thresholds are set to avoid overdiagnosis of cancers that would never cause harm.
How much does a thyroid ultrasound cost?
Cost varies widely depending on your insurance, the facility, and your location. Most insurance plans cover a thyroid ultrasound when ordered by a clinician for an appropriate indication. Contact your insurance provider to confirm coverage and any out-of-pocket costs before scheduling.
When to contact your clinician
- —You received a recommendation for biopsy but have not been scheduled — follow up promptly rather than waiting
- —New symptoms after a biopsy: increasing pain, swelling, bruising, or any signs of infection at the needle site
- —Newly noticed or rapidly growing lump in your neck that was not there before your scheduled follow-up
This article explains what thyroid ultrasound involves as a procedure and how results are interpreted in general. It is not a substitute for your clinician's review of your actual imaging report. The right next step depends on the specific features of your nodule and your full clinical picture.
References
- 1.Haugen BR, Alexander EK, Bible KC, et al. (2016). 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid. doi:10.1089/thy.2015.0020 ✓Ultrasound feature assessment criteria, biopsy thresholds, surveillance intervals, and growth-based trigger for repeat biopsy in thyroid nodules
- 2.Tessler FN, Middleton WD, Grant EG, et al. (2017). ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee. Journal of the American College of Radiology. doi:10.1016/j.jacr.2017.01.046 ✓TI-RADS scoring system: five feature categories (composition, echogenicity, shape, margin, echogenic foci), point-based risk levels TR1–TR5, biopsy size thresholds by level, and repeat-imaging intervals
- 3.Ali SZ, Baloch ZW, Cochand-Priollet B, Schmitt FC, Vielh P, VanderLaan PA (2023). The 2023 Bethesda System for Reporting Thyroid Cytopathology. Thyroid. doi:10.1089/thy.2023.0141 ✓Six-category Bethesda classification used to interpret FNA biopsy cell samples, with updated risk-of-malignancy estimates for each category
3 sources, numbered by first appearance. General health information, not medical advice — synthetic demonstration content.