Thyroid imaging tests are used to diagnose or monitor thyroid conditions such as hyperthyroidism, thyroid nodules, thyroid cancer, enlarged thyroid gland (goiter) and thyroiditis. These tests can help a physician to determine the most effective treatment approach for a patient’s condition.

Types of thyroid imaging tests include:

• Thyroid scan
• Ultrasound
• CAT scan (computed axial tomography)
• MRI (magnetic resonance imaging)
• Octreotide scan
• PET scan (positron emission tomography)

Preparations for thyroid imaging tests vary depending on the type of test. However, most require little or no preparation. Patients may be asked to avoid eating or drinking for a period of time prior to the procedure. Medication regimens also may need to be altered.

Most thyroid imaging tests are outpatient procedures performed in a clinic or hospital. Each test unfolds differently. In most cases, patients are able to go home shortly after the test is complete.

Usually, a radiologist will examine the results of a thyroid imaging test within a few days and report the findings to the patient’s physician. The physician will then share these findings with the patient. 

Thyroid imaging tests are considered to be generally safe, with few or no harmful side effects. Various treatments are available if a thyroid imaging test confirms the presence of a thyroid problem. In many cases, a physician will prescribe a thyroid medication to treat the disease. In other cases, surgery may be necessary.