Thyroid Ultrasound: What to Expect and Why It Is Done

If your doctor felt a lump in your neck, found an abnormality on another imaging test, or wants to evaluate thyroid symptoms, a thyroid ultrasound is often the next step. This painless, radiation-free exam provides detailed images of your thyroid gland and any nodules it may contain.

Why Your Doctor Ordered a Thyroid Ultrasound

Thyroid ultrasounds are commonly ordered when a nodule is felt during a physical exam, blood tests show abnormal thyroid function (hyperthyroidism or hypothyroidism), an incidental finding appears on a CT scan, MRI, or PET scan (these are called incidentalomas), or there is a family history of thyroid cancer.

According to the American Thyroid Association, thyroid nodules are extremely common — they can be detected in up to 50 percent of adults when ultrasound is used. The good news is that the vast majority (over 95 percent) are benign.

What the Ultrasound Shows

A thyroid ultrasound produces real-time images of your thyroid gland, which sits at the front of your neck just below your Adam's apple. The radiologist evaluates the size and shape of the gland, the number, size, and location of any nodules, the characteristics of each nodule (solid, cystic, or mixed), blood flow patterns within nodules, and nearby lymph nodes.

Certain ultrasound features are associated with higher or lower risk of cancer. The American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) standardizes how nodules are described and helps determine whether a biopsy is needed.

What to Expect During the Exam

A thyroid ultrasound is simple and quick:

1. Lie back — You will lie on an exam table with your neck slightly extended (a pillow may be placed under your shoulders)
2. Apply gel — The sonographer applies warm gel to your neck
3. Scan — A small handheld transducer is moved across your skin, sending sound waves that create images on a screen
4. Duration — The exam typically takes 15 to 20 minutes
5. No restrictions — You can eat, drink, and take medications normally before and after

There is no radiation, no pain, and no preparation required. You can return to normal activities immediately.

Understanding Your Results

Your ultrasound report will describe any nodules found and their characteristics. Based on the TI-RADS scoring system, nodules are assigned a category:

• TR1: Benign — No biopsy needed
• TR2: Not suspicious — No biopsy needed
• TR3: Mildly suspicious — Biopsy if 2.5 cm or larger
• TR4: Moderately suspicious — Biopsy if 1.5 cm or larger
• TR5: Highly suspicious — Biopsy if 1 cm or larger

If a biopsy is recommended, it is typically done as a fine needle aspiration (FNA) — a quick procedure where a thin needle removes a small sample of cells for analysis.

Most Nodules Are Benign

Even when a biopsy is performed, the National Cancer Institute reports that thyroid cancer accounts for only about 5 to 15 percent of nodules that are biopsied. The majority turn out to be benign conditions like colloid nodules, cysts, or thyroiditis.

If cancer is found, thyroid cancer is generally highly treatable. The five-year survival rate for the most common types exceeds 98 percent when caught early.

When Follow-Up Ultrasound Is Needed

If your nodule is benign or low-risk and does not require biopsy, your doctor may recommend periodic follow-up ultrasounds to monitor for changes. A typical schedule is a repeat ultrasound in 12 to 24 months. If the nodule remains stable over time, monitoring intervals may be extended.

If a nodule grows significantly or changes in appearance, biopsy may be reconsidered.

Schedule Your Thyroid Ultrasound

At Advanced Medical Imaging, our experienced sonographers and board-certified radiologists provide thorough thyroid evaluations with same-day appointments and fast results. If your doctor has ordered a thyroid ultrasound, call (727) 398-5999 or schedule online.