Sodium iodide taken orally for evaluation of hyper- or hypothyroidism is called a

• A. NM Technologist
• B. Health Physicist
• C. Thyroid Uptake Study
• D. Radiation Safety Officer

Answer: (C)

The idea being tested is measuring how much iodine the thyroid takes up after an oral dose of radioactive sodium iodide. This thyroid uptake study uses a small amount of radioactive iodine that the thyroid concentrates, and then counts are taken at set times to determine the percentage of the dose the gland traps. The amount the thyroid takes up reflects its activity: increased uptake indicates overactivity as in hyperthyroidism, while decreased uptake points to reduced trapping, as seen in certain forms of hypothyroidism or thyroiditis. The result helps differentiate causes of thyrotoxicosis and guides management. The other options are job titles, not a diagnostic test.