Home / Topics / Atomic & Nuclear Physics
Medical uses of radiation
Beginner
Imaging, PET scans and radiotherapy.
X-rays and CT for imaging, PET (positron emitters like F-18), gamma cameras (Tc-99m), radiotherapy for cancer, and sterilisation.
Tc-99m T½ = 6 hours.
Dose balances benefit against risk.
In more detail
Radiation is used in medicine for diagnosis, such as X-rays and PET scans, and for treatment, such as radiotherapy for cancer. The dose is carefully controlled to balance benefit and risk.
Real-world uses
- X-rays and CT scans are routine diagnostic tools.
- Radiotherapy targets tumours with precise beams.
- Hospitals use PET scans with positron-emitting tracers to see metabolic activity inside the body.
Open the interactive lesson, with simulation and quiz →
Frequently asked questions
What is PET?
A scan using positron-emitting tracers to show metabolic activity.
How is radiotherapy targeted?
Using multiple beams and imaging to focus dose on the tumour.
How does a PET scan work?
A tracer emits positrons that annihilate with electrons, producing two gamma rays detected by the scanner.
Related topics in Atomic & Nuclear Physics
Interaction of radiation with matter · Radiation units · Biological effects of radiation · Nuclear shell model · Liquid drop model · Nuclear spin and magnetic moment