technetium-99m

Technetium-99m is a metastable radioactive isotope of technetium widely used as a radiopharmaceutical in nuclear medicine. It acts as a radioactive tracer that can be detected in the body using gamma cameras and SPECT imaging. Technetium-99m emits gamma rays with an energy of approximately 140 keV and has a physical half-life of about six hours, which allows for effective imaging while minimizing radiation exposure to patients[1][2][4]. Its chemistry enables it to be incorporated into various biologically active compounds (radiotracers), allowing targeted imaging of organs such as the skeleton, heart muscle, brain, thyroid, lungs, liver, spleen, kidneys, gall bladder, bone marrow and more[1][2][6]. The mechanism involves intravenous administration of a compound labeled with technetium-99m; this compound accumulates in specific tissues depending on its chemical structure. The emitted gamma radiation is then detected externally to create diagnostic images. Technetium-99m is produced from molybdenum-99 generators supplied to hospitals and clinics worldwide[1][4][6]. It is the most commonly used medical radioisotope globally—employed in over 80% of all nuclear medicine procedures—and plays an essential role in diagnosing cancer (including sentinel lymph node mapping), cardiovascular disease (myocardial perfusion), bone disorders and other conditions[5][6][7].

Brand names

Technescan HDP

Other names

Tc-99mTc99mTc 99m99mTc