Search results
Results from the WOW.Com Content Network
Positron emission tomography (PET) [1] is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, regional chemical composition, and absorption.
Brain positron emission tomography is a form of positron emission tomography (PET) that is used to measure brain metabolism and the distribution of exogenous radiolabeled chemical agents throughout the brain. PET measures emissions from radioactively labeled metabolically active chemicals that have been injected into the bloodstream.
When radiolabeled with 11 CH 3, choline is a useful a tracer in PET imaging. Carbon-11 is radioactive with a half-life of 20.38 minutes. [1] By monitoring the gamma radiation resulting from the decay of carbon-11, the uptake, distribution, and retention of carbon-11 choline can be monitored.
Another fraction of [18 F]FDG, representing about 20% of the total fluorine-18 activity of an injection, is excreted renally by two hours after a dose of [18 F]FDG, with a rapid half-life of about 16 minutes (this portion makes the renal-collecting system and bladder prominent in a normal PET scan). This short biological half-life indicates ...
PET is a functional imaging technique that produces a three-dimensional image of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron -emitting radionuclide ( tracer ), which is introduced into the body on a biologically active molecule.
Pittsburgh compound B (PiB) is a radioactive analog of thioflavin T, which can be used in positron emission tomography scans to image beta-amyloid plaques in neuronal tissue. Due to this property, Pittsburgh compound B may be used in investigational studies of Alzheimer's disease .
A major medical use of fluorine-18 is: in positron emission tomography (PET) to image the brain and heart; to image the thyroid gland; as a radiotracer to image bones and seeking cancers that have metastasized from other locations in the body and in radiation therapy treating internal tumors.
For a bone scan, the patient is injected with a small amount of radioactive material, such as 700–1,100 MBq (19–30 mCi) of 99m Tc-medronic acid and then scanned with a gamma camera. Medronic acid is a phosphate derivative which can exchange places with bone phosphate in regions of active bone growth, so anchoring the radioisotope to that ...