Diagnostic reference levels in medical imaging: review and additional advice.

Diagnostic reference levels (DRLs) should be used by regional, national and local authorised bodies. The numerical values of DRLs are advisory, however, implementation of the DRL concept may be required by an authorised body. The concept of DRLs allows flexibility in their selection and implementation. The present ICRP advice does not specify quantities, numerical values or details of implementation for DRLs. This is the task of the regional, national and local authorised bodies, each of which should meet the needs in its respective area. ICRP considers that any reasonable and practical approach, consistent with the advice, will improve the management of patient doses in medical imaging.