What is Positron Emission Tomography PPT?
Positron Emission Tomography is an imaging technique which uses small amounts of radiolabeled biologically active compounds to help in the diagnosis of disease. The tracers are introduced into the body, by either injection or inhalation of a gas.
How does positron emission tomography work physics?
PET works by using a scanning device (a machine with a large hole at its center) to detect photons (subatomic particles) emitted by a radionuclide in the organ or tissue being examined.
What is Positron Emission Tomography technique?
Positron emission tomography (PET) 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.
What is the principle of PET?
The principle of positron emission tomography (PET) is that radiation emitted from a radiopharmaceutical injected intravenously into a patient is registered by external detectors positioned at different orientations.
What is PET in radiology?
A Positron emission tomography (PET scan) is a specialized service in radiology using nuclear medicine. A PET scan creates images to show how well organs or tissues in the body are functioning.
What is a positron and what is its symbol?
A positron is a particle with the same mass as an electron, but with a positive charge. Like the beta particle, a positron is immediately ejected from the nucleus upon its formation. The symbol for a positron in an equation is e+01. For example, potassium-38 emits a positron, becoming argon-38.
Why is PET combined with CT?
Combined PET/CT scanners perform almost all PET scans today. These combined scans help pinpoint abnormal metabolic activity and may provide more accurate diagnoses than the two scans performed separately.
What is the difference between SPECT and PET?
The main difference between SPECT and PET scans is the type of radiotracers used. While SPECT scans measure gamma rays, the decay of the radiotracers used with PET scans produce small particles called positrons. A positron is a particle with roughly the same mass as an electron but oppositely charged.
What are positrons made from?
Positrons are the antiparticles of electrons. The major difference from electrons is their positive charge. Positrons are formed during decay of nuclides that have an excess of protons in their nucleus compared to the number of neutrons. When decaying takes place, these radionuclides emit a positron and a neutrino.
Are positrons gamma rays?
Positrons are positively charged and annihilate with electrons, producing γ rays.