Table 1 Types of diagnostic reference levels (DRLs), methods of derivation, and areas of application (from ICRP-135 [1])
From: How to establish and use local diagnostic reference levels: an ESR EuroSafe Imaging expert statement
Term | Area and facilities surveyed | Value in distribution used to set DRL | Application |
|---|---|---|---|
Typical values | Healthcare facility consisting of several X-ray rooms or a small number of facilities or single facilities linked to a new technique | Median value of the distribution, as there are insufficient data to use the third quartile | Local use to identify X-ray units requiring further optimisation |
Local DRL | X-ray rooms within a few healthcare facilities (e.g., with at least 10–20 X-ray rooms) in a local area | Third quartile of median values for individual X-ray rooms | Local use to identify X-ray units requiring further optimisation |
National DRL | Representative selection of facilities covering an entire country | Third quartile of median values for individual X-ray rooms or of national values | Nationwide to identify X-ray facilities where optimisation is Needed |
Regional DRL | Several countries within one continent | Median values of distributions of national values or 75th percentile of distribution for representative selection of healthcare facilities throughout the region | Countries within region without a relevant DRL or for which national DRL is higher than regional value |