The Thyroid is a butterfly-shaped gland that wraps around the front part of your neck just below your Adam’s apple. The Thyroid makes hormones that help control your body’s metabolism. The hormone produced by the Thyroid has an effect on almost every tissue and cell in your body.
The Thyroid operates as part of a feedback loop involving body parts called the Hypothalamus and the Pituitary gland. First, the hypothalamus sends a signal to your pituitary gland through a hormone called TRH. When your pituitary gland receives this signal, it releases another hormone called TSH to your thyroid gland. Upon receiving TSH, your thyroid releases 2 of its own hormones (T3 and T4), which then enter your bloodstream and affect the metabolism of your heart, liver, muscles, and other organs. Finally, your pituitary gland monitors the level of thyroid hormone in your blood and increases or decreases the amount of TSH released, which then changes the amount of thyroid hormone in your blood.
Ultrasound is like ordinary sound except it has a frequency (or pitch) higher than human beings can hear. When sent into your body from a device called a transducer resting on your neck, the sound echoes back from the organs inside your body. These returning echoes are converted by a computer into a picture. During your thyroid ultrasound examination, ultrasound will produce pictures of your thyroid gland, including its size, shape, and blood vessels. The ultrasound will reveal any nodules (lumps) or cysts (lumps with fluid) that may be present in your thyroid gland. An ultrasound examination is commonly called the practice of sonography, but also may be referred to as diagnostic ultrasound imaging.
There are many reasons for examining the thyroid with ultrasound. The most common reason is to provide more information for your doctor about the following:
- A mass your doctor felt while examining you;
- Something unusual was found by other exams, such as a nuclear scan, a CT scan, or an MRI exam;
- What caused your thyroid gland to get larger;
- What caused the pain or swelling in your thyroid gland; or
- Abnormalities in your thyroid, such as masses or cysts.
A sonogram may not provide all the information your doctor needs. In these cases, more studies or tests may be needed. These may include blood tests; a biopsy in which your doctor removes a small amount of cells or fluid; or other types of ultrasound examinations.