Establishment of Diagnostic Reference Levels for Computed Tomography (Ct) Dose Optimization of Some Selected Hospitals in North Central Nigeria
Robert et al.
Abstract
Computed Tomography (CT) is an essential diagnostic tool, but its increasing use raises concerns about radiation exposure and associated risks. Diagnostic Reference Levels (DRLs) serve as benchmarks for dose optimization, guiding facilities to review practices when doses are unusually high or low. DRLs are not dose limits but investigative tools for improving radiation protection. This study aimed to establish facility diagnostic reference levels (FDRLs) in selected hospitals in North Central Nigeria, providing baseline data for regional and national DRLs. A retrospective cross-sectional study was conducted from May 2017 to October 2018, analyzing CT examinations from 109 patients across three centers (39, 28, and 42 per site). Only patients weighing 67–73 kg were included. Scans were performed using GE BrightSpeed 16-slice (Centre A), GE Optima CT660 64-slice (Centre B), and Philips Brilliance 16-slice (Centre C) scanners. SPSS version 20 was used to obtain 75th percentile dose metrics for establishing DRLs. DRLs (CTDIvol): Head 56.5 mGy, Chest 10.6 mGy, Abdomen 15.5 mGy; corresponding DLPs 1786.4, 844.6, and 1758.2 mGy·cm. FDRLs: Centre A, CTDIvol Head 44.3, Chest 6.9, Abdomen 13.3 mGy; DLP Head 1630.4, Chest 698.5, Abdomen 1646.2 mGy·cm. Centre B, CTDIvol Head 38.6, Abdomen 14.4 mGy; DLP Head 1535.4, Abdomen 1758.2 mGy·cm. Centre C, CTDIvol Head 60.9, Chest 10.6, Abdomen 15.5 mGy; DLP Head 2359.9, Chest 916.6, Abdomen 1913.3 mGy·cm. CTDIvol values aligned with major studies, though DLPs were higher. CTDIvol values were comparable internationally, but elevated DLPs highlight the need for tighter scan length control and dose optimization. Findings from three facilities and 109 patients provide insight but calls for wider validation.
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