UKHSA Medical Dosimetry Group (MDG) is responsible for developing, maintaining and publishing National Diagnostic Reference Levels (NDRLs) for the UK.

Diagnostic Reference Levels are dose levels in diagnostic imaging or interventional radiology procedures for typical examinations for groups of standard-sized individuals. They are used by healthcare professionals to help optimise the radiation exposure of patients.

The UK NDRLs are published on the GOV.UK website. Details of all previous NDRLs are also accessible from the same page.

MDG carries out regular surveys of radiation doses across the UK. These are repeated approximately every 5 years and cover lots of typical medical X-ray imaging procedures, such as planar X-ray imaging, dental, CT, fluoroscopy and interventional radiography.

More recently, dose surveys are also often undertaken by professional bodies, normally in collaboration with MDG. These tend to focus on highly specialised areas where NDRLs may not have been published previously.

If you are considering conducting any dose survey where the results may be suitable for adoption as NDRLs please read the available guidance and get in touch with us.

Details of on-going dose surveys that aim to update or add to the current NDRLs will be listed on this page.