Technetium Tc-99m pertechnetate

Technetium Tc-99m pertechnetate is a radiopharmaceutical diagnostic agent composed of an oxoanion with the chemical formula TcO4-. Pertechnetate has a wide variety of uses within nuclear medicine as it distributes within the body to a similar extent as iodine. It also concentrates in the thyroid gland, salivary glands, gastric mucosa, and choroid plexus. However, in contrast to the iodide ion, the pertechnetate ion is released unchanged from the thyroid gland. Currently marketed as the product Drytec, technetium-99m pertechnetate is indicated for imaging of the following tissues: thyroid, salivary gland, urinary bladder (for detection of vesico-ureteral reflux), and the nasolacrimal drainage system.

Technetium-99m's short half life (6 hours) makes storage impossible, therefore it is supplied as its parent nuclide molybdenum-99, which spontaneously decays to technetium-99 through beta decay. This is normally supplied in a hospital setting through the use of a technetium-99m generator, whereby technetium exits the generator in the form of the pertechnetate ion, TcO4−, which can be extracted and promptly used for clinical diagnostics. Following intravenous injection, single photon emission computed tomography (SPECT) is performed to detect the gamma ray emmitted by the decay of Technetium-99m to Technetium-99.