Which nuclide is use to investigate human thyroid gland disorders?

The nuclide used to diagnose and investigate thyroid disorders is radioactive iodine-131 ($^{131}$I). It is a gamma emitter with a half-life of 8.02 days, making it suitable for both diagnostic and therapeutic purposes.

Key points about the use of $^{131}$I in thyroid studies:

Diagnostic Use (Thyroid Scanning)

- $^{131}$I is commonly used in thyroid scanning procedures, which help visualize and assess the structure and function of the thyroid gland.

- A small amount of $^{131}$I is administered to the patient.

- The thyroid gland selectively absorbs iodine, concentrating the radioactive isotope.

- Gamma radiation emitted by $^{131}$I is detected using specialized gamma cameras or scanners, generating images (scintigrams) that show the size, shape, and activity of the thyroid gland.

- Thyroid scans can identify abnormalities such as nodules, goiters, or areas of excessive or insufficient iodine uptake.

Treatment of Hyperthyroidism

- In cases of hyperthyroidism, where the thyroid gland is overactive and produces excessive thyroid hormones, $^{131}$I can be used as a therapeutic agent.

- A higher dose of $^{131}$I is administered orally.

- The concentrated iodine in the thyroid gland emits radiation that destroys thyroid cells, reducing the overproduction of thyroid hormones and eventually leading to a more controlled thyroid function.

It's important to note that the use of radioactive iodine should be carefully managed by healthcare professionals to ensure appropriate dosing and monitoring of patients undergoing thyroid studies or treatment.