Date of Publication :31st May 2024

Abstract: Background: Multidetector computed tomography (MDCT) represents a significant advancement in CT imaging. However, with the increasing frequency of repeated CT examinations, concerns about cumulative radiation exposure arise. Minor variations in patient positioning, scan length, and technical parameters between follow-up scans can influence dose. This study aimed to investigate the variability in radiation dose among serial abdominal CT examinations performed using MDCT scanners using the same scanner with a standardized scanning protocol.
Materials & Methods: This cross-sectional study received approval from the Institutional Review Board (IRB) of the King Abdullah International Medical Research Centre (KAIMRC). Data on the computed tomography dose index volume (CTDIvol) and dose-length product (DLP) were retrospectively extracted, compiled, and analyzed for 140 patients (100 males, 40 females) who underwent two consecutive non-contrast Abdomen CT (AB-CT) examinations between January 2022 and June 2023. All scans were performed on the same MDCT system Philips, equipped with automated exposure control, using data retrieved from the RIS/PACS database at the Medical Imaging CT Unit, King Abdulaziz Medical City (KAMC), Riyadh, Saudi Arabia.
Results: This study found no statistically significant variation in radiation dose metrics between the two CT scans.; mean CTDIvol decreased from 33.27 to 31.26 mGy and DLP from 894.33 to 829.34 mGy·cm. technical parameters, including tube voltage, exposure time, table height, and slice thickness, showed minimal, non-significant variation, indicating consistent scanning protocols across both visits.
Conclusion: The analysis confirmed no significant differences in radiation dose or scan parameters between the two follow-up CT visits. These findings suggest consistent application of imaging protocols and effective use of dose management strategies, including automated exposure control on the MDCT scanner.

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