A radioisotope of technetium which decays by isomeric transition, emitting an essentially monoenergetic gamma ray of 142 keV with a half-life of 6.01 hr. It is usually obtained from a radionuclide generator of molybdenum-99 and is used to prepare radiopharmaceuticals for scanning the brain, parotid, thyroid, lungs, blood pool, liver, heart, spleen, kidney, lacrimal drainage apparatus, bone, and bone marrow.
99mTc diphosphonate, a radionuclide complex used for bone scans.
99mTc-DPTA, a radionuclide chelate complex used for renal imaging and function testing.
99mTc sulfur colloid, a particulate radionuclide complex taken up by the reticuloendothelial system; used for imaging the liver and spleen.