A process description to establish clinical indicated diagnostic reference level values for abdominal computed tomography examinations.

Diagnostic reference level (DRL) values are used to optimize radiation dose during medical imaging. The International Commission on Radiological Protection (ICRP) proposes that clinical indicated diagnostic reference level (ciDRL) values must be established for imaging modalities using ionising radiation. The clinical indication of the patient determines the imaging protocol to be used; therefore, the ciDRL will be a more reliable representation of the different examinations as compared to anatomical DRL values. This paper discusses practical guidelines that can be used by a dose and image quality optimization (DIQO) team in a hospital setting to establish ciDRL values in computed tomography (CT) for chest-abdomen-pelvis (CAP) and abdomen-pelvis (AbP) examinations for adult patients. The guidelines can also be used by researchers who want to determine ciDRL values for a specific patient size using the size specific dose estimates (SSDE). The first step is to identify the most common clinical indication for an anatomical region. Thereafter, at least 20 patients or more are required per clinical indication to compile ciDRL values for CT. The ciDRL values established for CT should be based either on the typical values (median) or the 75th percentile according to the ICRP guidelines. Having ciDRL values has the potential to ensure radiation dose is reasonably distributed for the respective CAP and AbP CT examinations. After reading this Continuing Medical Education (CME) article, the reader will be able to.