Medical radiation: uses, dose measurements and safety advice

The use of ionising radiation in medicine, including recommended dose measurements and guidance on safe radiology practice.

Ionising radiation is used in medicine in 3 ways:

  • diagnostic radiology, which uses x-ray machines to obtain images of the inside of the patient’s body
  • nuclear medicine, which uses radioactive substances introduced into the patient for diagnosis or treatment
  • radiotherapy, which uses many types and sources of ionising radiation to cure or relieve symptoms of cancer and other diseases

These 3 areas are covered by the Ionising Radiation (Medical Exposure) Regulations 2017, which provide a framework to protect patients.

Two guidance documents have been produced in partnership with the Royal College of Radiologists, Society and College of Radiographers, Institute of Physics and Engineering Medicine and other professional bodies. The documents are entitled: Ionising Radiation (Medical Exposure) Regulations: Implications for clinical practice in radiotherapy and Ionising Radiation (Medical Exposure) Regulations: Implications for clinical practice in diagnostic imaging, interventional radiology and diagnostic nuclear medicine. The later document also extends to research labs, universities and sports facilities where medical and non-medical exposures are undertaken.

Medical radiation: risks and safety advice

Incident learning in clinical imaging, MRI and nuclear medicine

Diagnostic radiology

Nuclear medicine

There’s a dedicated committee, Administration of Radioactive Substances Advisory Committee (ARSAC), to advise the government on nuclear medicine.


Updates to this page

Published 1 August 2014
Last updated 22 April 2024 + show all updates
  1. Added a section on "Incident learning in clinical imaging, MRI and nuclear medicine", which includes 2 new pages.

  2. Added link to 'Medical imaging: what you need to know'.

  3. Added link to the new 'Computed tomography (CT): national patient dose audits' page.

  4. Added links to 2 Ionising Radiation (Medical Exposure) Regulations guidance documents.

  5. Added: Development of learning from radiotherapy errors.

  6. Added Medical radiation: national diagnostic reference levels (NDRLs), based on existing research.

  7. The 'Safer radiotherapy: supplementary survey analysis' has been added under 'Radiotherapy'.

  8. The 'Doses from computed tomography (CT) examinations in the UK report' has been uploaded.

  9. First published.