Impact of high-iodine concentration contrast material for dual-energy CT angiography on arterial visualization: A single-blind, randomized controlled trial

Purpose To investigate the effect of high-iodine concentration contrast material for dual-energy CT angiography (DECTA) on arterial visualizations by comparing it with medium-iodine concentration. Method This prospective, single-blind, randomized controlled trial included 100 consecutive participants undergoing DECTA from November 2023 to February 2025. The participants were randomly assigned into two protocols: receiving high-iodine concentration contrast material of 370 mgI/mL (Group A, n = 51) and receiving medium-iodine concentration of 300 mgI/mL (Group B, n = 49). The axial, coronal, and volume-rendered (VR) images were reconstructed at 40 keV in both groups. Two radiologists reviewed three image types and assessed the arterial visualizations using a five-point scale. The primary outcome was the score for the iliolumbar artery on the VR images, whereas secondary outcomes were the scores for all others. The Wilcoxon rank sum test was conducted to compare the outcomes between the two groups. Results No statistical significance in terms of the score for the iliolumbar artery on the VR images was found between the two groups; however, the median score was higher in Group A than in Group B (3.5 vs. 3.0; P = .05). The scores for secondary outcomes in Group A were equal to or greater than that in Group B, and significant differences were observed, especially in the small arteries, including the bronchial, internal thoracic, intercostal, left gastric, and inferior phrenic arteries ( P < .05). Conclusion In small arteries, the protocol with high-iodine concentration contrast material exhibited better arterial visualizations compared with medium-iodine concentration in DECTA at 40 keV.