Trends in Medical Ionizing Radiation Exposure from Diagnostic Imaging in Saudi Arabia: A Retrospective Analysis of Computed Tomography Utilization, Population Dose Estimates, and Associated Cancer Risk (2013–2022)

A BSTRACT Background: The rapid expansion of diagnostic imaging infrastructure globally has resulted in substantial increases in population exposure to medical ionizing radiation, with computed tomography (CT) accounting for the majority of collective dose. Saudi Arabia has undergone accelerated diagnostic imaging growth under Saudi Vision 2030, yet national trend data on CT utilization, population dose, and associated cancer risk remain limited. This study characterized trends in diagnostic CT utilization, estimated population-level effective dose, and quantified associated lifetime attributable cancer risk in Saudi Arabia between 2013 and 2022. Materials and Methods: This retrospective cross-sectional study analyzed the secondary data from Saudi Ministry of Health facility statistics, WHO Global Health Observatory imaging infrastructure data, and published dosimetry studies. Annual CT examination volumes were estimated from scanner density and utilization rate data. Effective dose per examination was derived from published diagnostic reference levels. Collective and per-capita effective doses were calculated. Lifetime attributable risk of radiation-induced cancer was estimated using the Linear No-Threshold model with risk coefficients from the Biological Effects of Ionizing Radiation VII report. Data were analyzed by imaging modality, body region, sex, and age group. Results: Estimated national CT examination volume increased from approximately 1.2 million in 2013 to 3.1 million in 2022, representing a 158.3% increase. CT scanner density grew from 9.4 to 21.6 units per million population. Per-capita annual effective dose from CT increased from 0.48 to 1.14 mSv. Abdominopelvic CT contributed the highest collective dose (38.2% of total). Chest CT volume increased fourfold between 2019 and 2021 driven by coronavirus disease 2019 diagnostic utilization. Estimated lifetime attributable cancer risk from annual CT exposure reached 1 in 1430 by 2022. Pediatric CT examinations accounted for 8.3% of total volume with disproportionate dose contribution. Conclusions: Medical ionizing radiation exposure from diagnostic CT in Saudi Arabia has more than doubled over the past decade, with estimated cancer risk approaching levels warranting systematic population-level radiation protection measures. Enforcing justification and optimization principles, establishing national diagnostic reference levels, and implementing pediatric dose reduction protocols are urgent preventive priorities.