Radiation Dose Assessment in Routine Adult Computed Tomography Examinations: A Multi-center Retrospective Study.

BACKGROUND

Computed tomography (CT) plays an essential role in diagnosing and imaging various body structures, but it continues to be one of the most frequent sources of medical radiation exposure. Diagnostic reference levels (DRLs) represent critical values for radiation dose monitoring and dose optimization.

OBJECTIVE

The study aims to investigate levels of radiation dose in adult routine CT examinations in Saudi Arabia and establish local diagnostic reference levels (DRLs) for head, chest, and abdomen/pelvis CT studies.

METHODS

A multicenter retrospective cross-sectional analysis involving 300 routine CT examinations was carried out on adults. The dataset includes 100 head CTs, 100 chest CTs, and 100 abdomen/pelvis CTs from two hospitals in Saudi Arabia during the period of April-July 2025. Dose descriptors (CTDIvol, DLP) were collected based on CT dose reports; E was calculated. Radiation dose distributions were summarized using descriptive statistics, and local DRLs were established using the 75th percentile of CTDIvol and DLP values. Dose levels were compared with published national and international reference values.

RESULTS

The local diagnostic reference levels (CTDIvol and DLP) were 52.07 mGy and 949.41 mGy cm for head CTs, 11.04 mGy and 576.12 mGy cm for chest CTs, and 14.73 mGy and 805.63 mGy cm for abdomen/pelvis CTs. Compared with the relevant reference levels, the CTDIvol was 13.2% lower than the EC reference level for head CT, 8.0% lower than the SFDA national DRL for chest CT, and 5.2% higher than the SFDA national DRL for abdomen/pelvis CT.

CONCLUSION

The established DRLs for the routine adult CT exams are consistent with the current standards set for radiation dose monitoring and optimization. The continuous surveillance of radiation exposure and the optimization of image acquisition protocols should be done in order to improve patient radiation protection without image quality being compromised.