Thoracic Computed Tomography Angiographies Using Contrast Medium Power Injectors in Children with Cardiovascular Diseases: Analysis of Contrast Attenuation, Image Quality, and Radiation Exposure

Background: The purpose of this study was to retrospectively analyze image quality and contrast attenuation of thoracic computed tomography angiographies (CTA) in children using an automated power injector for contrast medium (CM) application.

Methods: In 128 children (< 18 years) 160 CTA studies with ECG synchronization were performed using a 3rd generation dual source scanner. We evaluated routes and flow rates of CM administration using an automated power injector. To evaluate the objective image quality, we determined the signal-to-noise ratios of the relevant anatomical structures and calculated the contrast-to-noise ratios (CNR) thereof. Clinical image quality was assessed by two independent raters using a four-point Likert-scale. Radiation exposure was analyzed by calculating the effective doses based on dose length products and specific conversion factors. The total population, as well as three age-specific subgroups were analyzed: neonates (≤ 28 days), infants (> 28 days to ≤ year), and children (> year to ≤ 18 years).

Results: CM was administered either via central or peripheral venous catheters. Central venous administration was performed in neonates in 71.0%, in infants in 35.0%, and in older children in 2.4%. Mean flow rates of CM application were 0.89 mL/s (0.5 -1.5) in neonates, 0.98 mL/s (0.5–1.5) in infants, and 1.99 mL/s (1.0–5.0) in children > 1 year. There were no complications associated with the CM application. Automated contrast application yields high attenuation values for different target territories with CNR (LV): 22.07 ± 11.96, CNR (RV): 21.29 ± 14.34, CNR (aorta): 26.31 ±13.54, CNR (pulmonary trunc): 26.03 ± 17.39, which were comparable in all pediatric age groups. The qualitative rating revealed good to excellent imaging quality in 91.6% for rater 1 and 94.1% for rater 2 respectively with a good interrater correlation (r = 0.71–0.87, p < 0.001). Mean effective dose for all examinations was 0.74 (± 0.66) mSv. When analyzing age-specific subgroups, mean effective doses were 0.44 (± 0.26) mSv for neonates, 0.74 (± 0.87) mSv for infants and 0.87 (± 0.60) mSv for children >1 year.

Conclusion: CTA using automated power injectors provides high objective and clinical image quality in all pediatric age groups even if low CM volumes and flow rates are required. CM can be administered safely via different venous catheters. CTA in children can be acquired routinely with a radiation dose below 1 mSv.

Publication History

Article published online:
13 February 2024