CAIE A-Level Physics A2 24.3.6 The Gamma Ray Photons From an Annihilation Event Travel Outside the Body and Questions
Practise explaining how opposing gamma photons are detected and timed in PET, relating the data to an image of tracer concentration in tissue.
Syllabus
2028–2030
Course
Physics 9702
Level
A2
Exam points
explain how opposing gamma photons are detected and their arrival times processed
relate PET photon detection data to an image of tracer concentration in tissue
CAIE A-Level Physics A2 24.3.6 The Gamma Ray Photons From an Annihilation Event Travel Outside the Body and Questions question 1
[Maximum number: 2]
Fluorine-18 (918F) is a radioactive nuclide that is used as a tracer in positron emission tomography (PET scanning). Fluorine-18 decays to a nuclide of oxygen ( O ) according to
918F⟶PQX+8RO.
Explain how the detection of the gamma-ray photons is used to produce an image of the tissue being examined.
arrival times of photons are processed image built up of tracer concentration in the tissue