Size-Specific Dose Estimate Assessment in Adult Non-Contrast Computed Tomography Abdomen: A Cross-Sectional Dose Evaluation Study

Abstract To evaluate and compare conventional radiation dose metrics (computed tomography dose index volume [CTDIvol] and dose length product [DLP]) with size-specific dose estimates (SSDEs) in adult patients undergoing non-contrast computed tomography (NCCT) abdomen examinations. This study aimed to evaluate radiation dose metrics in adult NCCT abdomen examinations with particular emphasis on SSDE and to compare the findings with international diagnostic reference levels. A retrospective analysis of 130 adult patients was performed. CTDIvol and DLP were recorded from scanner-generated dose reports, and effective dose was calculated using standard abdominal conversion coefficients. SSDE was derived using patient anteroposterior and lateral body dimensions based on American Association of Physicists in Medicine TG-204 recommendations. The mean CTDIvol and DLP were 8.59 ± 2.13 mGy and 405.2 ± 121.46 mGy·cm, respectively, with a calculated effective dose of 6.08 ± 1.82 mSv. The mean SSDE was 13.53 ± 3.03 mGy, significantly higher than CTDIvol (p < 0.01). All dose indices were below the American College of Radiology and International Atomic Energy Agency reference levels. The study demonstrates that reliance on CTDIvol significantly underestimates the absorbed radiation dose in adult NCCT abdomen examinations. Incorporating SSDE provides a more accurate, patient-specific estimation of actual radiation dose.