Department of Medicine (Cardiology), University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON, Canada K1Y 4W7.
Eur Heart J Cardiovasc Imaging. 2014 Feb;15(2):210-5. doi: 10.1093/ehjci/jet144. Epub 2013 Aug 13.
We sought to quantify coronary artery calcium (CAC) using a single contrast-enhanced cardiac computed tomography angiography (CCTA) study. CCTA has been successfully used for the assessment of coronary artery stenoses, whereas non-contrast ECG-gated computed tomography (Standard-CAC) is commonly performed to quantify CAC. Thus each scan individually contributes to the total radiation dose.
Patients who underwent both Standard-CAC and CCTA scans were identified. Standard-CAC images were scored using the Agatston method. CCTA scans were scored for CAC (CCTA-CAC), whereby CAC was defined as plaque with attenuation 2 SD above the mean attenuation value of the ascending aorta (HU(aorta)). The correlation between Standard-CAC and CCTA-CAC was determined with the slope used to derive a correction factor for the conversion of CCTA-CAC results to a Standard-CAC Agatston score (AS). To test applicability, the correction factor was assessed in a separate validation cohort of similar demographics. From April 2011 to June 2012, a derivation cohort of 92 patients was identified and analysed. An additional 47 patients were identified for the validation cohort. Correlation between Standard-CAC and CCTA-CAC was excellent (r = 0.96). The slope (y = 2.74 × CCTA-CAC score) derived correction factor from the derivation cohort was used to adjust CCTA-CAC derived scores to an AS (CCTA-CAC(corrected) = 2.74 × CCTA-CAC). The correction factor was applied to the validation cohort CCTA-CAC results with excellent agreement between CCTA-CAC(corrected) and Standard-CAC (kappa = 0.93).
Quantification of CAC from a single contrast-enhanced CCTA scan is feasible and correlates well with Standard-CAC. Larger, multicentre studies are needed to validate the universal applicability of CAC quantified using CCTA.
我们试图通过单次对比增强心脏 CT 血管造影（CCTA）研究来定量冠状动脉钙（CAC）。CCTA 已成功用于评估冠状动脉狭窄，而非对比增强心电图门控 CT（标准-CAC）通常用于定量 CAC。因此，每次扫描都会单独增加总辐射剂量。
确定了同时接受标准-CAC 和 CCTA 扫描的患者。使用 Agatston 方法对标准-CAC 图像进行评分。CCTA 扫描用于 CAC（CCTA-CAC）评分，CAC 定义为衰减值比升主动脉平均衰减值高 2 个标准差的斑块（HU（主动脉））。确定了标准-CAC 和 CCTA-CAC 之间的相关性，并使用斜率来得出转换 CCTA-CAC 结果为标准-CAC Agatston 评分（AS）的校正因子。为了测试适用性，在具有相似人口统计学特征的单独验证队列中评估了校正因子。
从 2011 年 4 月至 2012 年 6 月，确定了一个包含 92 例患者的推导队列进行分析。另外确定了 47 例患者作为验证队列。标准-CAC 和 CCTA-CAC 之间的相关性非常好（r = 0.96）。从推导队列中得出的斜率（y = 2.74 × CCTA-CAC 评分）用于校正 CCTA-CAC 评分的校正因子，以调整 AS 的 CCTA-CAC 评分（CCTA-CAC（校正）= 2.74 × CCTA-CAC）。校正因子应用于验证队列 CCTA-CAC 结果，CCTA-CAC（校正）与标准-CAC 之间具有极好的一致性（kappa = 0.93）。
从单次对比增强 CCTA 扫描定量 CAC 是可行的，与标准-CAC 相关性良好。需要更大规模、多中心的研究来验证使用 CCTA 定量 CAC 的普遍适用性。
