technet99m
Technetium-99m, often written Tc-99m, is a metastable nuclear isomer of technetium-99. It emits gamma radiation with a predominant energy of about 140 keV and has a half-life of roughly 6.01 hours, properties that make it well suited to diagnostic imaging with conventional gamma cameras and single-photon emission computed tomography (SPECT). Tc-99m is produced in a Mo-99/Tc-99m generator, where the parent isotope molybdenum-99 decays to Tc-99m. The eluate is typically received as sodium pertechnetate (TcO4−) and then incorporated into radiopharmaceuticals for imaging.
A key feature of Tc-99m is its ability to be labeled to a variety of molecules, producing
Tc-99m radiopharmaceuticals provide high-contrast images with relatively low radiation doses and enable rapid imaging protocols. The
Safety and regulation: handling requires specialized facilities, and radiopharmaceuticals are administered in controlled doses under regulatory
History: Since the 1960s, Tc-99m has become the most widely used medical radioisotope for diagnostic imaging