Technetium 99m

Technetium-99m (99mTc) is a radioisotope of technetium which is used in tens of millions of medical diagnostic procedures annually, making it the most commonly used medical radioisotope.

Physical characteristics

Technetium-99m is a metastable nuclear isomer of technetium-99, symbolized as 99mTc, that is used in tens of millions of medical diagnostic procedures annually, making it the most commonly used medical radioisotope. It decays into technetium-99 by isomeric transition, a process that emits gamma rays which can be detected by a gamma camera.

Medical uses

Technetium-99m is used in radiopharmaceuticals for a wide variety of diagnostic tests. It is used in over 80% of all nuclear medicine procedures worldwide. These include bone scans, thyroid scans, brain scans, heart scans, lung scans, liver scans, spleen scans, kidney scans, and infection scans.

Production

Technetium-99m is usually obtained from a molybdenum-99/technetium-99m generator and is used as a radioactive tracer in the human body. The molybdenum-99 decays to produce technetium-99m.

Safety

Technetium-99m is considered safe for medical use because it emits low energy gamma rays, has a short half-life of 6 hours, and is excreted from the body relatively quickly.

See also

• Nuclear medicine
• Radioisotope
• Radiopharmaceutical
• Gamma camera