Comparison of radiation dose and image quality between contrast-enhanced single- and dual-energy abdominopelvic computed tomography in children as a function of patient size

Background: Widespread adoption of dual-energy computed tomography (DECT) requires evidence it does not cause higher radiation dose than conventional single-energy CT (SECT). While a few publications involving pediatric patients exist, most have focused on small cohorts. Hence, there is still a need for studies that ascertain what radiation doses are expected in larger populations that include representative ranges of patient sizes and ages. Objective: To compare radiation dose and image quality of DECT and SECT abdominopelvic examinations in children as a function of patient size. Materials and methods: This retrospective study included 860 children (age range: 12.3±5.3 years) who underwent contrast-enhanced abdominopelvic exams on second-generation dual-source CT in a five-year period. Two groups, SECT and DECT, consisting of 430 children each, were matched by 5 effective diameters. Volume CT dose index (CTDI_vol) and size-specific dose estimate (SSDE) were analyzed as a function of effective diameter. Objective image quality was compared between the groups. Results: DECT SSDEs were lower across all effective patient diameters compared with SECT (mean: 8.5±1.8 mGv vs. 9.3±2.0 mGv, respectively, P≤0.001). DECT CTDI_vol was lower compared to SECT (mean: 5.6±2.4 mGv vs. 6.1±2.7 mGv, respectively, P≤0.001) except in the smallest diameter group (<15 cm) where it was comparable to SECT (P=0.065). Objective image quality versus effective diameter between the two CT groups was comparable (P>0.05). Conclusion: In children, regardless of effective diameter, contrast-enhanced abdominopelvic DECT can be performed with a similar or lower dose and similar image quality compared with SECT examinations.