Radioactive tracers
- A radioactive tracer is defined as:
A substance containing radioactive nuclei that is introduced to the body and can be absorbed by tissue in order to study the structure and function of organs in the body
- Radioactive isotopes, such as technetium-99m or fluorine-18, are suitable for this purpose because:
- they both bind to organic molecules, such as glucose or water, which are readily available in the body
- they both emit gamma (γ) radiation and decay into stable isotopes
- technetium-99m has a short half-life of 6 hours (it is a short-lived form of Technetium-99)
- fluorine-18 has an even shorter half-life of 110 minutes, so the patient is exposed to radiation for a shorter time