COMPARISON OF PATIENT RADIATION DOSES IN MULTI SLICE AND SINGLE SLICE CT SCAN AT MEDAN TEACHING HOSPITAL

Abstract

The increasing reliance on Computed Tomography (CT) as a cornerstone of diagnostic imaging raises critical concerns about patient radiation safety. While CT offers unparalleled anatomical detail, cumulative ionizing radiation exposure highlights the need for dose optimization strategies, especially with rising scan volumes and vulnerable populations. Despite technological advancements such as the transition from single-slice CT (SSCT) to multi-slice CT (MSCT), comparative data on patient dose profiles remain limited in resource-constrained environments, including many educational hospitals in Indonesia. This study addresses the gap by quantifying and comparing patient radiation doses delivered by SSCT and MSCT at a tertiary educational hospital in Medan, North Sumatra, with a focus on the Dose-Length Product (DLP). Using a retrospective comparative design, data were collected from 200 adult patients undergoing CT head, chest, and abdomen/pelvis examinations over six months (100 on SSCT, 100 on MSCT). DLP values were extracted from the Picture Archiving and Communication System (PACS) and standardized dose monitoring systems. Independent samples t-tests compared mean DLPs, with Cohen’s d quantifying effect sizes. Results revealed significant dose reductions with MSCT across all protocols. For head CT, mean DLP was 48.5 ± 12.2 mGy·cm on SSCT versus 35.2 ± 9.8 mGy·cm on MSCT, a 27.4% reduction (d = 0.98). Chest CT demonstrated 450.3 ± 85.6 mGy·cm on SSCT versus 325.7 ± 60.2 mGy·cm on MSCT, a 27.7% reduction (d = 1.15). Abdomen/pelvis CT showed a 23.0% reduction (620.8 ± 110.5 vs. 480.1 ± 95.3; d = 1.05). These findings indicate MSCT consistently delivers lower radiation doses, confirming the hypothesis of technological efficiency. This study validates the ALARA principle in Indonesia, with practical implications for scanner procurement, protocol standardization, and quality assurance. Recommendations include mandatory adoption of MSCT protocols, radiographer training in optimized techniques, and establishing local diagnostic reference levels (DRLs). Future studies should assess the relationship between dose reduction and diagnostic image quality, as well as the role of iterative reconstruction in enhancing safety.