Comparative analysis of radiation dose distribution in multi-phase tomography angiography procedures

Computed tomography angiography (CTA) multi-scan protocols significantly increase radiation exposure due to repeated imaging phases, resulting in higher cumulative doses. This study evaluated radiation dose parameters across three CTA protocols to identify variations and potential optimization strategies. A retrospective analysis was conducted in Khartoum, Sudan, involving 119 adult patients who underwent renal, liver, and lower limb CTA. Radiation dose metrics, including the dose-length product (DLP) and volume CT dose index (CTDIvol), were recorded, and effective dose estimations were performed. The mean CTDI ranged from 5.3 to 8.8 mGy, while the effective dose (ED) spanned from 16.3 to 32.0 mSv, with a mean of 20.9 ± 4.1 mSv. For renal CTA examinations, the total DLP ranged from 809.4 to 2687.9 mGy cm, and the corresponding ED ranged from 12.1 to 40.3 mSv. The findings demonstrate that CTA procedures result in variable radiation exposure depending on the anatomical region scanned and the scanning protocol used, with observed doses often exceeding those reported in previous studies. Continued efforts are needed to refine scanning protocols and minimize unnecessary radiation exposure.