Department of Radiology, University Medical Center Utrecht, PO Box 85500, 3508 GA Utrecht, the Netherlands.
Department of Anatomy, University Medical Center Utrecht, PO Box 85500, 3508 GA Utrecht, the Netherlands.
Eur J Radiol. 2022 Jan;146:110080. doi: 10.1016/j.ejrad.2021.110080. Epub 2021 Dec 1.
Computed tomography (CT) might be a good diagnostic test to accurately quantify calcium in vascular beds but there are multiple factors influencing the quantification. The aim of this study was to investigate the influence of different computed tomography protocol settings in the quantification of calcium in the lower extremities using modified Agatston and volume scores.
Fresh-frozen human legs were scanned at different tube current protocols and reconstructed at different slice thickness. Two different iterative reconstruction protocols for conventional CT images were compared. Calcium was manually scored using modified Agatston and volume scores. Outcomes were statistically analyzed using Wilcoxon signed-rank tests and mean absolute and relative differences were plotted in Bland-Altman plots.
Of the 20 legs, 16 had CT detectable calcifications. Differences between thick and thin slice reconstruction protocols were 129 Agatston units and 125% for Agatston and 78.4 mm and 57.8% for volume (all p ≤ 0.001). No significant differences were found between low and high tube current protocols. Differences between iDose and IMR reconstruction protocols for modified Agatston were 34.2 Agatston units and 17.7% and the volume score 33.5 mm and 21.2% (all p ≤ 0.001).
Slice thickness reconstruction and reconstruction method protocols influenced the modified Agatston and volume scores in leg arteries, but tube current and different observers did not have an effect. This data emphasizes the need for standardized quantification of leg artery calcifications. Possible implications are in the development of a more universal quantification method, independent of the type of scan and vasculature.
计算机断层扫描（CT）可能是一种准确量化血管床钙的良好诊断测试，但有多种因素会影响定量分析。本研究旨在探讨不同 CT 协议设置对使用改良 Agatston 和容积评分定量下肢钙的影响。
将新鲜冷冻的人腿在不同的管电流协议下进行扫描，并在不同的切片厚度下进行重建。比较了两种不同的迭代重建协议用于常规 CT 图像。使用改良的 Agatston 和容积评分手动对钙进行评分。使用 Wilcoxon 符号秩检验对结果进行统计学分析，并在 Bland-Altman 图中绘制平均绝对和相对差异。
在 20 条腿中，有 16 条腿的 CT 可检测到钙化。厚切片和薄切片重建协议之间的差异为 129 个 Agatston 单位和 125%的 Agatston 评分，78.4mm 和 57.8%的容积评分（均 p ≤ 0.001）。低管电流和高管电流协议之间没有发现显著差异。iDose 和 IMR 重建协议之间改良 Agatston 评分的差异为 34.2 个 Agatston 单位和 17.7%，容积评分的差异为 33.5mm 和 21.2%（均 p ≤ 0.001）。
切片厚度重建和重建方法协议会影响下肢动脉的改良 Agatston 和容积评分，但管电流和不同观察者没有影响。这些数据强调了对下肢动脉钙化进行标准化定量的必要性。可能的影响是开发一种更通用的量化方法，独立于扫描类型和血管类型。
