Thyroid ultrasound in Seoul, with a doctor's view

What a thyroid ultrasound in Seoul involves

The thyroid is a butterfly-shaped gland at the front of the neck that controls how fast your body uses energy. A thyroid ultrasound uses sound waves to produce a detailed picture of the gland and the tissues around it.

You lie on your back with a small pillow under your shoulders so your neck is gently extended. Gel is applied, and a probe is moved over the front and sides of your neck. The scan is painless and typically takes 10 to 20 minutes. There is no radiation and no injection.

At VEI Clinic, a thyroid ultrasound in Seoul is ordered after a consultation with Dr. HyunSung Park, a board-certified internal medicine specialist. He examines your neck, reviews symptoms and medicines, and decides which blood tests, such as TSH, free T4 and thyroid antibodies, will help interpret the scan.

What thyroid ultrasound can show

Ultrasound is the main test for looking at the structure of the thyroid. It is especially useful for describing nodules, because their appearance guides whether they can simply be watched.

• The size of the gland and whether it is enlarged (goiter)
• Nodules: their number, size, location and features such as solid or cystic content, margins, calcifications and shape
• Patterns that suggest inflammation, such as the texture seen in Hashimoto's thyroiditis
• Lymph nodes in the neck when they need assessing
• Changes over time when compared with earlier scans

What it cannot tell you

Ultrasound shows structure, not function. Whether your thyroid is overactive or underactive is decided by blood tests, not by the scan. Ultrasound also cannot say for certain whether a nodule is benign or cancerous; it assigns a risk category. When a nodule has concerning features or reaches a certain size, the next step is a fine-needle aspiration (FNA) biopsy, which is done at a hospital or specialist center. We refer you with an English summary when it is needed.

It is also worth knowing that small thyroid nodules are very common, and most are benign. Routine ultrasound screening of people with no symptoms or risk factors is not generally recommended, because it finds many harmless nodules that lead to unnecessary tests. Dr. Park will tell you honestly whether a scan is worthwhile for you.

Who it suits, and who may not need it

Thyroid ultrasound suits people with a lump felt or seen in the neck, a nodule found on another scan, an enlarged thyroid, a family history of thyroid cancer or a history of neck radiation, and those due for follow-up of known nodules. It can also help when blood tests suggest thyroiditis.

If you have tiredness or weight change but a normal neck exam, blood tests usually come first, and a scan may not add anything. Our separate thyroid nodule and Hashimoto's pages go deeper into those specific conditions.

Korea offers a well-known lesson here. When thyroid ultrasound became a common add-on to health checkups, the number of small thyroid cancers diagnosed rose sharply, while deaths from thyroid cancer barely changed. That pattern is widely cited as overdiagnosis, and it is why we prefer to scan for a clear reason.

Preparation, results and red flags

No fasting is needed. Wear a top with an open neckline and remove necklaces. If you take biotin (vitamin B7) supplements, tell us, as high doses can distort some thyroid blood tests; stopping them for a few days before the blood draw is often advised. Bring any earlier ultrasound reports or images so nodules can be compared accurately.

After the scan, Dr. Park explains the findings, the risk category of any nodule, and whether you need reassurance only, a repeat scan, a biopsy referral or an endocrinology opinion.

Call 119 or go to an emergency room if a neck swelling grows rapidly and causes difficulty breathing or swallowing, if you have noisy breathing, or if there is severe neck pain with high fever.