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Related to technetium-99m: metastable


the radionuclide most commonly used to image the body in nuclear medicine scans. It is preferred because of its short half-life and because the emitted photon has an appropriate energy for normal imaging techniques. The "m" indicates that this radionuclide is metastable. It is generated on site from a molybdenum source.


A radioactive isotope of technetium having a half-life of 6 hr, in which the “m” refers to the fact that it is a metastable isotope.. 99mTc is used in nuclear medicine for a wide variety of diagnostic tests and imaging studies, e.g., myocardial perfusion scans, bone scans, and V/Q scans..

technetium Tc 99m albumin aggregated injection

An injection of technetium-99m that has been aggregated with albumin. It is used intravenously to scan the lungs.

technetium Tc 99m hexamethylpropyleneamine oxime

Abbreviation: HMPAO
A radioactive tracer consisting of technetium-99m linked to hexamethylpropyleneamine oxime. It is used to make nuclear imaging scans of the brain, e.g., in the determination of brain death. Absence of uptake of the molecule by the brain is diagnostic of brain death.

technetium 99m (methoxyisonitrile) MIBI

A radioactive tracer consisting of technetium-99m linked to MIBI. It is used in nuclear medical imaging (e.g., in scintimammography) to identify cancerous breast masses. Other uses of technetium 99m MIBI include cardiac, parathyroid, and thyroid imaging.

technetium Tc 99m methylene diphosphonate

A radioactive tracer consisting of technetium-99m linked to methylene diphosphonate. It is used in nuclear medicine to obtain images of bone and bone diseases, e.g., fractures not seen on plain x-rays, malignancies, and osteomyelitis.

technetium Tc 99m RBC

A radioactive tracer consisting of technetium-99m linked to red blood cells. It is used in clinical medicine to evaluate occult bleeding, e.g., from the gastrointestinal tract, or the motion of the heart in gated blood pool imaging.
Synonym: red blood cell scan

technetium Tc 99m sestamibi

A radioactive tracer consisting of technetium-99m linked to sestamibi. It is used to image blood flow to the heart muscle, esp. when combined with exercise or pharmacological “stress” tests. In a heart with normal blood flow, the isotope should be taken up uniformly throughout the heart muscle. Decreased uptake by regions of the heart occurs when coronary artery blood flow to those regions is blocked, e.g., by atherosclerotic plaque. Synonym: sestamibi

technetium Tc 99m sulfur colloid

A radioactive tracer consisting of technetium-99m linked to sulfur colloid. It is used in nuclear medicine scans to make images of gastric emptying or of the lymph nodes, liver, and spleen.


a chemical element, atomic number 43, atomic weight 99, symbol Tc. See Table 6.

the most frequently used radioisotope in nuclear medicine, a gamma emitter having a half-life of 6.04 hours and a primary photon energy of 140 keV; symbol 99mTc.
Tc sulfur coated scintiscan see scintiscan.
References in periodicals archive ?
Technetium-99m MAG3, a comparison with Iodine-123 and Iodine-131 Orthoiodohippurate, in patients with renal disorders.
Pre operative localization studies including ultrasound neck and technetium-99m sestamibi imaging had been carried out in all cases, the results of which were analyzed and compared.
Rhodes and her associates are running MBI scans on women who have received a dose of technetium-99m sestamibi for cardiac imaging.
Influence of tobacco on the labelling of red blood cells and plasma proteins with technetium-99m J.
Separate acquisition rest thallium-201/stress technetium-99m sestamibi dual-isotope myocardial perfusion single-photon emission computed tomography: a clinical validation study.
The one-step, almost instant, labeling method allows the use of technetium-99m, which is the preferred isotope in nuclear medicine, for diagnostic imaging (due to availability, low cost, and optimal imaging properties), as well as isotopes of rhenium, for therapy applications, such as in cancer and certain chronic inflammatory conditions (rheumatoid arthritis or arterial restenosis).
Technetium-99m has most of the ideal properties for an imaging isotope; a short half life of 6.
Lantheus' LEU TechneLite([R]) generator is the first technetium-99m (Tc-99m) generator in the United States that contains molybdenum-99 (Mo-99) produced from at least 95 percent LEU.
Mallinckrodt's Nuclear Imaging business is a producer of the medical isotope molybdenum-99, and its derivative, Technetium-99m, which is used in nuclear medicine procedures worldwide.

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