Establishing Local Diagnostic Reference Levels (DRLs) for Adult Computed Tomography in Emirates Health Services Hospitals: A Multicenter Dose Survey

Objectives: This study aimed to establish local Diagnostic Reference Levels (DRLs) for adult computed tomography (CT) across Emirates Health Services (EHS) hospitals in the United Arab Emirates. Methods: A retrospective multicenter survey included 1257 adult patients from seven EHS hospitals who underwent six routine CT protocols: head without contrast (n = 375), chest without contrast (n = 403), chest with contrast (n = 50), abdomen–pelvis without contrast (n = 204), abdomen–pelvis with contrast (n = 164), and chest–abdomen–pelvis (n = 61). Only single-phase, standard-range examinations were included. Examinations with major protocol deviations, extended scan ranges, or manual exposure overrides were excluded. CTDIvol and DLP were extracted from DICOM dose reports and reviewed against protocol definitions and scanner dose documentation. Local DRLs were defined as the 75th percentile of the dose distribution for each protocol, and median values were reported as achievable dose indicators. Results: Inter-hospital variability was observed across all protocols, particularly for abdomen–pelvis and chest–abdomen–pelvis examinations. The proposed DLP-based local DRLs (mGy·cm) were: head without contrast, 1179.6; chest without contrast, 425.0; chest with contrast, 1238.0; abdomen–pelvis without contrast, 637.2; abdomen–pelvis with contrast, 1269.9; and chest–abdomen–pelvis, 1411.5. Median values indicated achievable doses below the 75th percentile for all protocols. Compared with selected international studies, abdomen–pelvis doses were broadly comparable, whereas head and chest doses were somewhat higher. Conclusions: This study provides a coordinated multicenter baseline for adult CT local DRLs across EHS hospitals. The findings support protocol harmonization, scan-length optimization, targeted staff training, and integration with dose-monitoring systems to strengthen CT dose optimization and patient safety and to inform future updates of UAE national DRLs.