CT重组算法对低剂量胸部CT筛查冠状动脉钙化积分准确性影响研究

The Effect of CT Reconstruction Kernel on the Accuracy of Low-Dose Chest CT Screening for Coronary Artery Calcification Scores

目的以门控CT为金标准,探讨不同CT重组算法对非门控胸部低剂量CT(LDCT)评估冠状动脉钙化(CAC)的影响。方法回顾性分析本院参与“三大疾病筛查”同时接受门控CT和非门控胸部LDCT扫描的718例患者资料。根据扫描方案的不同分为门控、非门控两组,根据重组方式的不同,将后者依次使用smooth、standard及sharp三种算法进行图像重组,并同时对所有图像进行冠状动脉钙化积分(CACS)。将Agatston评分分为4个标准的评分类别(Agatston评分:0、1~99、100~399、>400)。然后采用组内相关系数(ICC)、Spearman秩相关分析对CACS进行分析,同时利用Kappa检验4组图像获得心血管风险分层的准确性。结果CACS结果显示门控CT与非门控胸部LDCT之间一致性很好,其中smooth最高(体积ICC=0.932、质量ICC=0.904、Agatston ICC=0.906,P=0.000)。非门控与门控图像间的基于Agatston评分类别一致性也很高,smooth、standard、sharp Kappa值分别为0.757、0.745、0.654,其中smooth法观察到有最少的患者被重新分类。非门控胸部LDCT图像辐射剂量指标均显著低于门控CT(P均<0.001),且有效剂量降低达41.2%。结论胸部LDCT是一种较可靠的检测和定量评估CAC的成像方法。在非门控胸部LDCT中选择smooth重组算法,可以最大程度地提高CAC评估的准确性。

Objective Taking ECG gated CT as the gold standard,explore the influence of different CT reconstruction algorithms on the assessment of coronary artery calcification(CAC)by low dose chest tomography(LDCT).Methods A retrospective analysis of 718 patients in our hospital who received ECG gated CT and LDCT scans at the same time.According to the different schemes,it was divided into two groups:ECG gated and LDCT.According to the reconstruction methods,the latter used three algorithms of smooth,standard,and sharp to reconstruct images,and performed CACS on all images.The Agatston score was divided into 4 standard scoring categories(Agatston score:0,1~99,100~399 and>400).Then the intra group correlation coefficient and Spearman were used to analyze CACS,and Kappa to test the accuracy of cardiovascular risk stratification.Results The results of CACS showed that the ECG gated CT and LDCT had a great agreement,and smooth was the highest(volume ICC=0.932 mass ICC=0.904 Agatston ICC=0.906;P=0.000).The agreement between LDCT and ECG gated CT images based on the Agatston score category is also very high.The Kappa values are 0.757,0.745,and 0.654,respectively.The smooth has the fewest patients to be reclassified.The radiation dose of LDCT images was lower than that of ECG gated CT(P<0.001),and the effective dose was reduced by 41.2%.Conclusion The LDCT is a more reliable method for detecting and quantitatively evaluating CAC.Choosing the smooth algorithm in LDCT can maximize the accuracy of CAC assessment.