Establishing local diagnostic reference levels (LDRLs) for eight common adult radiographic examinations: A single-centre digital radiography study with international comparison.

Diagnostic reference levels (DRLs) are widely used tools for optimizing patient radiation protection in diagnostic radiology. The aim of this study was to establish local diagnostic reference levels (LDRLs) for common adult radiographic examinations performed with direct digital radiography in a single provincial hospital in Morocco and to compare these values with published national and international references. A total of 320 adult patients of standard body habitus were included during routine clinical practice between January and March 2025. Eight radiographic projections were evaluated: skull PA, chest PA, abdomen AP, pelvis AP, lumbar spine AP and lateral, and cervical spine AP and lateral. Patient characteristics and exposure parameters, including tube voltage (kVp), tube current-time product (mAs), focus-to-detector distance (FDD), and focus-to-skin distance (FSD), were recorded for each examination. ESD was calculated using a standardized dosimetric formalism, and the 75th percentile of the ESD distribution was adopted as the LDRL for each projection. The established LDRLs ranged from 0.22 mGy for chest PA to 13.33 mGy for lumbar spine lateral projections. LDRLs for chest, abdomen, and cervical spine examinations were comparable to or lower than most published reference values. In contrast, lumbar spine projections showed the highest dose levels and exceeded several international benchmarks, indicating increased irradiation for this examination. These results provide a local baseline for dose audit and protocol review in adult digital radiography and highlight lumbar spine imaging as a priority area for dose optimisation. The established LDRLs may support ongoing quality assurance activities and contribute to the harmonization of radiological protection practices.