Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, South Carolina 29425, USA; Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, Milan, Italy.
Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, South Carolina 29425, USA; Heart and Vascular Centre, Semmelweis University, Varosmajor utca 68, Budapest 1122, Hungary.
Acad Radiol. 2024 Sep;31(9):3570-3578. doi: 10.1016/j.acra.2024.04.039. Epub 2024 May 11.
Coronary CT angiography (CCTA) has recently been established as a first-line test in patients with suspected coronary artery disease (CAD). Due to the increased use of CCTA, strategies to reduce radiation and contrast medium (CM) exposure are of high importance. The aim of this study was to evaluate the performance of automated tube voltage selection (ATVS)-adapted CM injection protocol for CCTA compared to a clinically established triphasic injection protocol in terms of image quality, radiation exposure, and CM administration MATERIAL AND METHODS: Patients undergoing clinically indicated CCTA were prospectively enrolled from July 2021 to July 2023. Patients underwent CCTA using a modified triphasic CM injection protocol tailored to the tube voltage by the ATVS algorithm, in a range of 70 to 130 kV with a 10 kV interval. The injection protocol consisted of two phases of mixed CM and saline boluses with different proportions to assure a voltage-specific iodine delivery rate, followed by a third phase of saline flush. This cohort was compared to a control group identified retrospectively and scanned on the same CT system but with a standard triphasic CM protocol. Radiation and contrast dose, subjective and objective image quality (contrast-to-noise-ratio [CNR] and signal-to-noise-ratio [SNR]) were compared between the two groups.
The final population consisted of 120 prospective patients matched with 120 retrospective controls, with 20 patients in each kV group. The 120 kV group was excluded from the statistical analysis due to insufficient sample size. A significant CM reduction was achieved in the prospective group overall (46.0 [IQR 37.0-52.0] vs. 51.3 [IQR 40.1-73.0] mL, p < 0.001) and at all kV levels too (all pairwise p < 0.001). There were no significant differences in radiation dose (6.13 ± 4.88 vs. 5.97 ± 5.51 mSv, p = 0.81), subjective image quality (median score of 4 [3-5] vs. 4 [3-5], p = 0.40), CNR, and SNR in the aorta and the left anterior descending coronary artery (all p > 0.05).
ATVS-adapted CM injection protocol allows for diagnostic quality CCTA with reduced CM volume while maintaining similar radiation exposure, subjective and objective image quality.
冠状动脉 CT 血管造影（CCTA）最近已被确立为疑似冠心病（CAD）患者的一线检查方法。由于 CCTA 的应用增加，降低辐射和造影剂（CM）暴露的策略非常重要。本研究旨在评估自动管电压选择（ATVS）适应的 CM 注射方案在图像质量、辐射暴露和 CM 给药方面与临床既定的三相注射方案相比的性能。
从 2021 年 7 月至 2023 年 7 月，前瞻性纳入接受临床指征 CCTA 的患者。患者使用改良的三相 CM 注射方案进行 CCTA，该方案根据 ATVS 算法针对管电压进行了调整，范围为 70-130kV，间隔 10kV。注射方案包括两阶段混合 CM 和盐水 bolus，其比例不同，以保证特定电压的碘输送率，然后是第三阶段盐水冲洗。将该队列与在同一 CT 系统上但使用标准三相 CM 方案扫描的回顾性对照组进行比较。比较两组的辐射和对比剂量、主观和客观图像质量（对比噪声比 [CNR] 和信噪比 [SNR]）。
最终人群包括 120 名前瞻性患者和 120 名回顾性对照患者，每个 kV 组有 20 名患者。由于样本量不足，120kV 组被排除在统计分析之外。前瞻性组总体上（46.0 [IQR 37.0-52.0] vs. 51.3 [IQR 40.1-73.0] mL，p < 0.001）和所有 kV 水平（均 p < 0.001）均显著减少 CM。两组之间的辐射剂量（6.13 ± 4.88 vs. 5.97 ± 5.51 mSv，p = 0.81）、主观图像质量（中位数评分 4 [3-5] vs. 4 [3-5]，p = 0.40）、CNR 和 SNR 在主动脉和左前降支冠状动脉中无差异（所有 p > 0.05）。
ATVS 适应的 CM 注射方案可实现诊断质量的 CCTA，同时减少 CM 体积，同时保持相似的辐射暴露、主观和客观图像质量。
