Invest Radiol. 2018 Feb;53(2):103-109. doi: 10.1097/RLI.0000000000000416.
The aim of this study was to evaluate a prototype dual-energy computed tomography calcium subtraction algorithm and its impact on luminal visualization in patients with heavily calcified coronary arteries.
Twenty-nine patients (62% male; mean age, 64 ± 7 years) who had undergone dual-energy coronary computed tomography angiography were retrospectively included in this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant study. Linearly blended (M_0.6) and calcium-subtracted images were reconstructed. Two independent observers assessed luminal visualization of the coronary arteries in a segment-based analysis, subjective image quality, and diagnostic confidence using 5-point Likert scales. Contrast-to-noise ratios for both data sets were calculated. Wilcoxon testing and Cohen's κ were used for statistical comparisons.
Calcium-subtracted image series showed improved lumen visualization of the coronary arteries (P = 0.008), with excellent interreader agreement (mean score, 3.3; κ = 0.82), compared with M_0.6 series (mean score, 2.9; κ = 0.77). The calcium subtraction algorithm improved diagnostic confidence compared with the M_0.6 reconstructions (mean scores, 4.0 and 3.1, respectively; all P ≤ 0.002). The image quality analysis showed no significant differences between calcium-subtracted and M_0.6 data sets (subjectively: mean scores, 4.1 and 4.2, respectively, P = 0.442; objectively: mean contrast-to-noise ratio, 37.0 and 38.2, respectively, P = 0.733).
A prototype algorithm for calcium subtraction improves coronary lumen visualization and diagnostic confidence in patients with heavy coronary calcifications without differences in conventional subjective and objective measures of image quality.
本研究旨在评估一种原型双能 CT 钙减影算法及其对重度钙化冠状动脉管腔可视化的影响。
本回顾性研究共纳入 29 例患者（62%为男性；平均年龄 64±7 岁），这些患者均接受了双能冠状动脉 CT 血管造影检查。本研究经机构审查委员会批准，符合《健康保险流通与责任法案》的规定。重建了线性混合（M_0.6）和钙减影图像。两位独立观察者基于节段进行了冠状动脉管腔可视性评估、主观图像质量和诊断信心的评估，使用 5 分李克特量表进行评分。计算了两种数据集的对比噪声比。采用 Wilcoxon 检验和 Cohen's κ 进行统计学比较。
与 M_0.6 系列相比，钙减影图像系列显示出改善的冠状动脉管腔可视化（P=0.008），具有极好的观察者间一致性（平均评分 3.3；κ=0.82）。与 M_0.6 重建相比，钙减影算法提高了诊断信心（平均评分分别为 4.0 和 3.1，均 P≤0.002）。图像质量分析显示，钙减影和 M_0.6 数据集之间无显著差异（主观评分：分别为 4.1 和 4.2，P=0.442；客观评分：平均对比噪声比分别为 37.0 和 38.2，P=0.733）。
一种原型钙减影算法可改善重度冠状动脉钙化患者的冠状动脉管腔可视化和诊断信心，而在传统的主观和客观图像质量测量方面无差异。
