Guidance

Diagnostic radiology: national diagnostic reference levels

Details of the national diagnostic reference levels (NDRLs), for clinicians using radiation in medicine.

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These tables give the national diagnostic reference levels for common X-ray examinations for patients.

NDRLs from previous years are also available:

Published 22 January 2016

Last updated 811 ~~July~~December 2025 + show all updates

11 December 2025
National DRLs for radiotherapy verification with Cone Beam CT have been published.

8 July 2025
NDRLs for general radiography, and fluoroscopy and interventional radiography have been updated.
20 November 2024
Added 'National Diagnostic Reference Levels (NDRLs) from 20 November 2024'.
24 November 2022
Added process to generate, adopt and maintain NDRLs.
13 October 2022
Updated with latest mammography and adult CT NDRLs. Year of publication also added to each NDRL value.
14 June 2022
Updated with latest update, including change to '2b. Paediatric CT examinations'.
19 August 2019
Added information on new NDRLs for dental radiography, and provided archive links to previous NDRLs.
15 November 2018
Added new data for NDRLs.
22 January 2016
First published.