A thyroid ultrasound is a non-invasive imaging test that uses high-frequency sound waves to create pictures of your thyroid gland and the surrounding structures in your neck. It's a very common and effective way for doctors to get a close look at the thyroid.
A thyroid ultrasound is primarily used to:
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Evaluate thyroid nodules: This is one of the most common reasons for a thyroid ultrasound. The scan can determine the size, number, and characteristics of any lumps or growths (nodules) on the thyroid. This information helps doctors decide if a biopsy or further testing is needed to check for cancer.
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Assess an enlarged thyroid (goiter): If your thyroid gland is unusually large, an ultrasound can help determine the size and structure of the goiter and what might be causing it.
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Check for inflammation (thyroiditis): The scan can reveal inflammation of the thyroid gland, which can be a sign of conditions like Hashimoto's disease or Graves' disease.
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Guide a biopsy: If a thyroid nodule looks suspicious, the ultrasound can be used in real-time to guide a fine-needle aspiration (FNA) biopsy, ensuring the needle is placed accurately into the nodule to collect a tissue sample.
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Look for abnormal lymph nodes: The ultrasound can also examine the lymph nodes in the neck to see if there are any signs of cancer that may have spread from the thyroid.
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Monitor changes over time: If you have known thyroid nodules or other conditions, a doctor may order a follow-up ultrasound to see if there have been any changes in their size or appearance.
It's important to note that a thyroid ultrasound shows the structure of the thyroid gland, not its function. To check how well your thyroid is working, your doctor would order blood tests to measure your hormone levels.