What is the mechanism of 99mTc MDP uptake by bone imaging?

What is the mechanism of 99mTc MDP uptake by bone imaging?

Mechanisms leading to increased extraosseous Tc-99m MDP uptake include extracellular fluid expansion, enhanced regional vascularity and permeability, and elevated tissue calcium concentration. The composition of the calcium deposition and the presence of other metallic ions (eg, iron and magnesium) are important.

Why is technetium 99m used in bone scans?

Technetium-99m methylene diphosphonate (MDP) is one of the most commonly used tracers for SS and its mechanism of action involves a complex interaction of bone repair and blood flow. SS targets the bony cortex, binding to the hydroxyapetite produced when the bone attempts to repair damage caused by metastases.

How does MDP bind to bone?

Mineralisation occurs at osteoblasts, representing sites of bone growth, where MDP (and other diphosphates) “bind to the hydroxyapatite crystals in proportion to local blood flow and osteoblastic activity and are therefore markers of bone turnover and bone perfusion”.

What is technetium 99m bone scan?

Bone scintigraphy (a.k.a. bone scans) are 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 99mTc used for?

Technetium-99m (99mTc) is a radionuclide nuclear agent that is FDA approved for diagnostic imaging of the brain, bone, lungs, kidneys, thyroid, heart, gall bladder, liver, spleen, bone marrow, salivary and lachrymal glands, blood pool, and sentinel nodes.

What is 99mTc pertechnetate?

Tc-99m pertechnetate (Na+ 99mTc O4-) is one of the technetium radiopharmaceuticals used in imaging of thyroid, colon, bladder and stomach. Technetium (99mTc) has eight oxidation states 6, from -1 to +7; specifically, the oxidation state of technetium in the pertechnetate anion (99mTcO4-) is +7.

How does technetium monitor bone growth?

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).

Where does Tc-99m MDP localize within the bone?

[2] Tc99m phosphonates localize to bone in proportion to osteoblastic activity as seen at sites of bony remodeling and, to a lesser extent, localizes in proportion to blood flow and its delivery of the radiotracer.

What does a technetium bone scan show?

A bone scan images the metabolic activity of the skeleton. This has traditionally been accomplished by imaging a radionuclide whose physiology closely mimics a metabolic process within bone. Nuclear scintigraphy of the bone commonly utilizes the radionuclides technetium-99m (Tc-99m) or fluoride-18 (F-18).

What is a triphasic bone scan?

A three phase bone scan is used to diagnose a fracture when it cannot be seen on an Xray. It is also used to diagnose bone infection, bone pain, osteomyelitis, as well as other bone diseases.

Why is 99mTc used in most cases?

Technetium-99m (Tc-99m) can be readily detected in the body by medical equipment because it emits 140.5 keV gamma rays (these are about the same wavelength as emitted by conventional X-ray diagnostic equipment), and its half-life for gamma emission is six hours (meaning 94% of it decays to 99Tc in 24 hours).

What is the meaning of pertechnetate?

Medical Definition of pertechnetate : an anion [TcO4]− of technetium used especially in the form of its sodium salt as a radiopharmaceutical in medical diagnostic scanning (as of the thyroid or brain)

Is bone imaging with 99mTc methylene diphosphonate a specific method of costochondritis diagnosis?

Study objectives: To determine whether bone imaging with 99mTc methylene diphosphonate is a specific method of making the diagnosis of costochondritis in patients with chest pain who rule out for myocardial infarction. Design: Nonblinded prospective controlled study in 20 patients and 10 control subjects.

What does [99mTc]MDP stand for?

Technetium-99m methylene diphosphonate ( [99mTc]MDP) is the most widely used bone-scanning agent today.

Is 99m Tc-MDP better than 18 F-FDG PET scan for osteosarcoma treatment?

The 99m Tc-MDP bone scan and 18 F-FDG PET scan are non-inferior to each other in predicting the histologic response of osteosarcoma treatments. The 99m Tc-MDP bone scan and 18 F-FDG PET scan showed respective advantages with differing features.

Where is the isotope [99mTc]MDP found in bone?

In the two groups that were injected with [99mTc]MDP, all bones showed the isotope to be clearly localized along mineralization fronts. The isotope was occasionally found in the substance of the osteoid, but was absent from the cytoplasm and nuclei of osteoblasts and osteocytes.