PET scanning
24.3What the syllabus asks of you
- understand that a tracer is a substance containing radioactive nuclei that can be introduced into the body and is then absorbed by the tissue being studied
- recall that a tracer that decays by β+ decay is used in positron emission tomography (PET scanning)
- understand that annihilation occurs when a particle interacts with its antiparticle and that mass–energy and momentum are conserved in the process
- explain that, in PET scanning, positrons emitted by the decay of the tracer annihilate when they interact with electrons in the tissue, producing a pair of gamma-ray photons travelling in opposite directions
- calculate the energy of the gamma-ray photons emitted during the annihilation of an electron-positron pair
- understand that the gamma-ray photons from an annihilation event travel outside the body and can be detected, and an image of the tracer concentration in the tissue can be created by processing the arrival times of the gamma-ray photons
Read the notes first
Chapter 24: PET scanning
Drill this topic
All 6 questions on PET scanning, untimed — answer on paper, then mark yourself against the mark scheme.
Make a worksheet
Choose the years and how many questions, then print it with the answers on separate pages.
6 questions
These are structured questions, answered in working rather than by picking an option, so they are not listed here one by one. The drill above puts each in front of you with its mark scheme to check against.