Centro Cardiologico Monzino, IRCCS, Via C. Parea 4, 20138, Milan, Italy.
Centro Cardiologico Monzino, IRCCS, Via C. Parea 4, 20138, Milan, Italy; Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.
J Cardiovasc Comput Tomogr. 2019 May-Jun;13(3):41-47. doi: 10.1016/j.jcct.2019.01.009. Epub 2019 Jan 4.
To assess evaluability and diagnostic accuracy of a low dose CT angiography (CTA) protocol for carotid arteries using latest Iterative Reconstruction (IR) algorithm in comparison with standard 100 kVp protocol using previous generation CT and IR.
105 patients, referred for CTA of the carotid arteries were prospectively enrolled in our study and underwent CTA with 80 kVp and latest IR algorithm (group 1). Data were retrospectively compared with 100 consecutive patients with similar examination indications that had previously undergone CTA of carotid arteries with a standard 100 kVp protocol and a first generation IR algorithm (group 2). Image quality was evaluated with a 4-point Likert-scale. For each exam CT number, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) at level of common carotid artery (CCA), internal carotid artery (ICA) and at level of Circle of Willis and Effective Dose (ED) were evaluated. 62 Group 1 patients underwent a clinically indicated DSA and results were compared with CTA.
No exams reported as not diagnostic. The overall mean CT number value of all arterial segments was above 450 HU in both groups. Significant lower noise, and higher SNR and CNR values were found in group 1 in comparison with group 2 despite the use of 80 kVp. In 62-group 1 patients studied by DSA, CTA showed in a segment-based analysis a sensitivity, negative predictive value and accuracy of 100%, 100% and 99% respectively. Mean ED in group 1 was 0.54 ± 0.1 mSv with a dose reduction up to 86%.
CTA for carotid arteries using latest IR algorithm allows to perform exams with submillisievert radiation exposure maintaining good image quality, overall evaluability and diagnostic accuracy.
评估使用最新迭代重建（IR）算法的低剂量 CT 血管造影（CTA）方案评估颈动脉的可评估性和诊断准确性，并与使用前一代 CT 和 IR 的标准 100kVp 方案进行比较。
前瞻性纳入 105 例因颈动脉 CTA 而就诊的患者，这些患者接受了 80kVp 和最新 IR 算法的 CTA（第 1 组）。回顾性比较了 100 例具有类似检查指征的连续患者，这些患者之前接受了标准 100kVp 方案和第一代 IR 算法的颈动脉 CTA（第 2 组）。使用 4 分李克特量表评估图像质量。评估每个检查的 CT 值、图像噪声、信噪比（SNR）、颈总动脉（CCA）、颈内动脉（ICA）水平和 Willis 环的对比噪声比（CNR）以及有效剂量（ED）。第 1 组的 62 例患者进行了临床提示的 DSA，将结果与 CTA 进行比较。
两组均未报告不可诊断的检查。两组所有动脉段的平均 CT 值均高于 450HU。尽管使用了 80kVp，但第 1 组的噪声显著降低，SNR 和 CNR 值更高。在 62 例接受 DSA 研究的第 1 组患者中，CTA 在基于节段的分析中显示出 100%的敏感性、100%的阴性预测值和 99%的准确性。第 1 组的平均 ED 为 0.54±0.1mSv，剂量降低了 86%。
使用最新 IR 算法的颈动脉 CTA 可在保持良好图像质量、总体可评估性和诊断准确性的情况下，以亚毫西弗辐射暴露进行检查。
