Chapter 5: Gamma Camera - Principles

16 flashcards · Biology · by Kristóf Nagy

1. Compton edge

   The energy at which Compton scattered photons have their maximum energy.45

2. Light guide

   A material used to direct light from the scintillator to the PMTs, optimizing light spread and improving uniformity.48

3. Spatial nonlinearity

   Non-uniform response of the gamma camera to events occurring at different positions, requiring calibration.49

4. PMT array

   An array of photomultiplier tubes used to convert the scintillation light into electrical signals and determine the position of the gamma ray interaction.4849

5. Hygroscopic

   A substance that readily absorbs moisture from the air.47

6. Sodium iodide (NaI)

   A common scintillator material used in gamma cameras due to its high light output and good energy resolution.47

7. Magnification (M)

   The ratio of the image size to the object size.4647

8. Diverging collimator

   A collimator where the holes diverge outward, providing a zoomed-out view of a larger field of view.47

9. Parallel-hole collimator

   A collimator with a series of parallel holes, commonly used for imaging larger objects.46

10. Collimator

    A device used in a gamma camera to selectively absorb gamma rays that are not travelling in a desired direction, improving image quality.4445

11. Gamma Camera

    A device that uses a scintillator, collimator, and PMT array to detect and image gamma rays emitted from radiotracers in a patient.144

12. Pinhole collimator

    A collimator with a single small hole, used for imaging small objects with high resolution.46

13. Multi-pinhole collimator

    A collimator with multiple pinholes, providing multiple simultaneous views for improved sensitivity.46

14. Backscatter peak

    A peak in an energy spectrum caused by gamma rays scattering back from surrounding materials before interacting with the scintillator.45

15. Photopeak

    The peak in an energy spectrum that corresponds to the full energy deposition of a gamma ray in the scintillator.45

16. Energy discrimination

    The process of rejecting scattered events based on their energy deposition in the scintillator.48