Question

which of the following diagnostic procedures uses radioactive iodine as part of the test?
a thyroid scan
b thyroid echography
c two - hour postprandial
d thyroid function test

Explanation:

• Thyroid scan: This procedure involves using radioactive iodine (such as iodine - 131 or iodine - 123). The thyroid gland has a high affinity for iodine. Radioactive iodine is taken up by the thyroid follicular cells. A gamma camera is then used to detect the radiation emitted by the radioactive iodine, which helps in visualizing the structure and function (uptake pattern) of the thyroid gland.
• Thyroid echography: It uses ultrasound waves (high - frequency sound waves) to create an image of the thyroid gland. There is no use of radioactive substances in this procedure.
• Two - hour postprandial: This is a test usually done to measure blood glucose levels 2 hours after a meal. It is mainly used in the diagnosis and management of diabetes mellitus and has no relation to radioactive iodine.
• Thyroid function test: This typically involves measuring the levels of thyroid - stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4) in the blood. These are biochemical tests and do not use radioactive iodine for the diagnostic procedure itself (although in some cases, for example, in the work - up of hyperthyroidism, a radioactive iodine uptake test might be done separately, but the basic thyroid function test panel does not use it).

Answer:

A. thyroid scan