What is the M in technetium 99m?

Technetium-99m is a metastable nuclear isomer, as indicated by the “m” after its mass number 99. This means it is a decay product whose nucleus remains in an excited state that lasts much longer than is typical.

What is the difference between Tc-99 and TC-99m?

Technetium-99 is produced during nuclear reactor operation, and is a byproduct of nuclear weapons explosions. Technetium-99 can be found as a component of nuclear waste. Technetium-99m is a short-lived form of Tc-99 that is used as a medical diagnostic tool.

What do we use technetium-99 for?

Technetium-99m is used to image the skeleton and heart muscle in particular, but also for brain, thyroid, lungs, liver, spleen, kidney, gall bladder, bone marrow, salivary and lachrymal glands, heart blood pool, infection and numerous specialized medical studies.

What is the decay constant of technetium-99?

Technetium-99 (99Tc) is an isotope of technetium which decays with a half-life of 211,000 years to stable ruthenium-99, emitting beta particles, but no gamma rays.

Why is technetium 99m the best?

Technetium-99m has a photopeak of gamma-ray emission of 140.5 keV, making it a very minimal risk of toxicity. [3] The short six-hour half-life and rapid excretion from the body limit toxic effects and give enough time to perform its diagnostic imaging, all while limiting radiation exposure to the patient.

How is technetium 99m used in bone imaging?

Technetium-99m MDP Tc-99m emits 140 keV gamma rays upon decay, and these gamma rays are detected by nuclear gamma cameras to allow localizing where the Tc-99m travels within the body. For imaging bone metabolism, the radionuclide is usually attached to medronic acid (methylene diphosphonate).

What is Tc-99m thyroid scan?

Technetium 99m pertechnetate (99mTcO4−) is a useful radioactive label for thyroid scanning. It is of particular merit when emphasis is placed upon a low dose of thyroid radiation, optimal resolution, and scanning of thyroid glands in which function is decreased or partly blocked.

How is technetium-99m administered?

Depending on site of administration and intended usage, Technetium 99m sulfur colloid enters the capillaries and is transported to the lymph nodes (subcutaneous injection), mixes with peritoneal fluid (intraperitoneal injection), is taken up by reticulocytes (intravenous injection), or enters the gastroesphageal tract …

How is technetium-99m used in bone scanning?

How do you calculate half-life of Tc-99?

The half-life of Tc-99m is 6.0 hours. Calculate the decay constant, λ, in s–1. Answer: 3.2 × 10–5 s–1 Calculate the molar activity in Bq mol–1. Answer: 1.9 × 1019 Bq mol–1 Calculate the time in hours for 90% of the activity of a sample of Tc-99m to decay.

Is technetium 99m stable?

The most stable radioactive isotopes are technetium-97 with a half-life of 4.21 million years, technetium-98 with 4.2 million years, and technetium-99 with 211,100 years.

Is technetium-99m used in MRI?

Technetium-99m (Tc-99m) sestamibi with or without single photon emission computed tomography (SPECT), ultrasound (US), CT, and magnetic resonance imaging (MRI) all are noninvasive techniques that can detect enlarged or abnormally functioning parathyroid tissue.

How is technetium-99m administered to a patient?

Why would a doctor order a thyroid ultrasound?

A thyroid ultrasound may be ordered if a thyroid function test is abnormal or if you doctor feels a growth on your thyroid while examining your neck. An ultrasound can also check an underactive or overactive thyroid gland. You may receive a thyroid ultrasound as part of an overall physical exam.

Does technetium-99m have side effects?

Most commonly, technetium-99m causes rash, angioedema, fever, and anaphylaxis due to hypersensitivity reactions. Patients may also experience a transient increase in blood pressure, seizures, arrhythmias, and syncope. When used in abdominal imaging, abdominal pain, vomiting, and diarrhea may occur.

How does technetium-99m scan work?

What does a technetium bone scan show?

The test is sensitive to differences in bone metabolism, which are highlighted in the body by the radioactive tracer. Scanning the whole skeleton helps in diagnosing a wide range of bone disorders, including: Fractures. Arthritis.

What is technetium bone scan?

Bone scintigraphy (a.k.a. bone scans) is a nuclear medicine (scintigraphic) study that makes use of technetium-99m (commonly Tc-99m-methylene diphosphonate (MDP)) as the active agent. The study has three phases which follow intravenous injection of the tracer. Sometimes a fourth (delayed/delayed) phase is performed.

What is the 8 hour decay factor for Tc-99m?

The half life for Tc99m is 6.01 hours. 6.01 ) = 171.73 mCi Remain after 8 hours of decay.