Diagnostic reference level

A diagnostic reference level is a specified radiation dose for a given imaging study that is not expected to be exceeded.

If a radiation dose does exceed the diagnostic reference level for a particular study, this should prompt an investigation into radiographic technique or equipment performance.

Diagnostic reference level values vary based on local, regional and national data. They are typically set at the 75th percentile of a distribution of radiation doses.

Entrance skin dose and dose area product are typically used to measure diagnostic reference level values in radiography and fluoroscopy.

CT dose index and dose length product are typically used to measure diagnostic reference level values in computed tomography.