Diagnostic reference levels for routine computed tomography angiography examinations: a systematic review

Background This work aims to investigate existing methodologies that have been used to establish diagnostic reference levels (DRLs) for common computed tomography angiography (CTA) examinations in adult patients by analyzing published national and local DRL studies. A detailed search through Science Direct, Web of Science, EBSCO host, PubMed-Medline, and Google Scholar was conducted. The preferred reporting items for systematic review and meta-analyses methodology was also used to evaluate the selected articles. Studies were selected via the PICOS method and included only DRL studies established for CTA examinations. Case studies, posters, reviews, and meta-analyses were excluded. The literature review identified 21 publications, 15 proposed a national DRL survey, and 6 studies with local (facility) data. Results A noticeable variation in DRL quantities for the same CTA procedures was noted among studies. Several factors contributed to this variability, including the methodologies used for establishing CTA DRLs, variations in scanning protocols, number of scanning phases, and scanner type. Conclusion There is a need for a global standardization for DRL establishment methods aligned with recent recommendations from prominent international radiation protection bodies to facilitate accurate comparisons of radiation dose metrics both between and within CT imaging facilities.