Positron emission tomography generally shows imaging of the physiology of the tumor as well as its anatomy, which is superior. It is unique compared to other cross-sectional imaging such as computed tomography or computed tomography (CT) or computed tomography. CT scans or MRIs often can not detect changes at the cellular level if the PET scan is capable of immediate changes. Identify in patient cells.
In order to image the tumor using PET or other methods, differences in basic features established in physiological and Metabolic of tumors and normal tissues. These differences include tumor surface antigens compared to cell tissues. Generally grow and DNA precursors such as thymidine and the rate of protein synthesis in tumors often increase compared to normal tissues. transport and Mixing of various amino acids, as well as anaerobic and aerobic glucose levels, are observed in tumor cells. In a wide range of Tumor types Glucose intake increases significantly compared to healthy tissues. In a typical PET system they are separated by a lead or tungsten blade detection of random photons in one shot Match with photons detected in other shots. In the diagram below, I plotted the average positron emitted energy from several desired radionuclides. Which of these radionuclides is best for our purposes?
Hello Mahyar Radak
The question you mention is very broad! As for which is so-called "better", it really depends what type of tumour you are testing for or evaluating. As we know, different types of tumours are better analysed with different types of PET scans and I know my colleagues generally think they (PET scans) are all the same but you and I know that is not true. Most commonly, they expect if someone is said to have had a PET scan, it most commonly refers to using F18-FDG and clinicians are often surprised when it turned out to be something else (!)
Hello Joseph C Lee
Exactly one of the purposes of asking these questions, I was to make sure that exactly different methods are used for each specific type of tumor and this thinking is improved by colleagues.
Best Wishes
Hello, any petct is optimized for F16 and this is logical since appr 95% of all use is Fdg. Is Fdg optimal? Well as a more intersting tracer Gallium can be used but just not that much available (since generator or nearby cyclotron is needed).
However the promise for GaFapi(as example) is enormous. But do expect a bit.worse IQ, peter
The energy of the emitted positrons is not so revelant, because the PET detectors react to the 511 keV PHOTONS emitted when the positron annihilates with an electron. The energy of the photons is always very similar, equal to the rest mass of the electron/positron.
What is really relevant is the drug the radionuclide is attached to, becuase the uptake within the patients body will depend on the biokinetics of said molecule. Usually 18F is used with the FDG molecule because it is an analog, strongly absorbed by cancer cells.
Miguel Angel de la Casa
Thank you very much for your helpful answer.
Positrons are emitted from an unstable nucleus. In a typical PET system, they are separated by a lead or tungsten blade The detection of random photons in one image coincides with the photons detected in other images. The emitted positrons posed by oxyglucose 18F may reach a maximum energy of 4.63Mev and may range from 3-2 Have millimeters inside the tissue. I mentioned the average energy in the graph
Hello Mahyar Radak
Although (18)FDG is the radiopharmaceutical used in PET imaging, Na18F has recently been studied, which has increased the sensitivity and specificity of imaging.
Of course, the most appropriate type of radiopharmaceutical can be different depending on the type of tumor and is not general.
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