摘要
目的 评价冠状动脉CT血管成像（CCTA）常规图像和单能量图像对钙化斑块狭窄测量的准确性.方法 采用动态心脏体模及冠状动脉钙化模型,进行常规120 kV及双能CCTA扫描.测量常规120 kV与50-160 keV（共12个能级,间隔10 keV）图像的客观图像质量,包括图像噪声、信噪比（SNR）及对比噪声比（CNR）.测量120 kV与50-160 keV钙化斑块管腔的狭窄程度,与金标准钙化模型真实狭窄程度做比较,做Bland-Altman一致性检验.以钙化模型真实管腔狭窄≥50%作为参照标准,计算CCTA的诊断敏感度、特异度及准确性;并参照模型真实狭窄,绘制CCTA的ROC曲线,并计算曲线下面积（AUC）值.结果 常规120 kV的SNR（76.4±16.1）及CNR（274.7±54.1）高于50-160 keV单能量图像,70 keV及以上的单能量图像的SNR及CNR逐渐减低.Bland-Altman分析显示,90-160 keV单能量成像与金标准模型真实狭窄一致性均较120 kV好,其中以100-130 keV与模型真实狭窄一致性最好,100-130 keV单能量测得的狭窄与金标准狭窄差值的算术平均值均为17.2%,120 kV算术平均值为21.4%.诊断特异度在120、130 keV时最高,为75.0%.ROC曲线下面积随着keV的增加呈增高的趋势,在90-130 keV的ROC曲线下面积（0.991-0.995）大于常规120 kV（0.990）.结论 使用双源CT单能量技术可以提高钙化斑块狭窄程度评估的准确性.以100-130 keV显示钙化病变较合适.
Objective To analyze the impact of dual energy monochromatic reconstructions （50-160 keV） on coronary calcified plaque stenosis quantification in a cardiac phantom with the real stenosis as standard of reference.Methods Signal-to-noise（SNR）and contrast-to-noise ratios（CNR）were calculated. In conventional 120 kV coronary CT angiography （CCTA） images as well as 12 monochromatic series（50-160 keV）,luminal narrowing of calcified plaque was measured and compared to the real stenosis. Bland-Altman plots were performed to analyze the correlation of reference standard with conventional 120 kV and 12 monochromatic series （50-160 keV）. The sensitivity, specificity, and accuracy of CCTA for detection of≥50% stenosis were calculated and receiver operating characteristic（ROC）curve was analyzed with the real stenosis as reference standard.Results The SNR and CNR were decreased with the increase of keV from 70 keV.The SNR and CNR of monochromatic imaging were lower compared with conventional 120 kV images（SNR：76.4±16.1;CNR：274.7±54.1）（P〈0.05）.The Bland-Altman plots presented a smaller measurement bias towards 90-160 keV than conventional 120 kV, and smallest measurement bias was revealed in 100-130 keV imaging（100-130 keV：bias 17.2% vs 120 kV：21.4%）.Using the stenosis≥50% as cut-off value, the specificity were higher in the monochromatic series （70-160 keV） than conventional 120 kV CCTA.The specificity（75.0%）were the highest in the 120 keV and 130 keV images.The area under the ROC curve（AUC）of 90-130 keV（0.991-0.995）was higher than that in conventional 120 kV imaging （0.990）. Conclusions The use of monochromatic imaging improves the overall accuracy of stenosis evaluation in coronary calcified plaques. Reconstructions at 100-130 keV for calcified lesions yielded the optimal results.
作者
李平
徐磊
刘亚峰
刘骥
王辉
张楠
杨琳
王瑞
周振
范占明
Li Ping, Xu Lei, Liu Yafeng, Liu Ji, Wang Hui, Zhang Nan, Yang Lin, Wang Rui, Zhou Zhen, Fan Zhanrning.(Department of Medical Imaging, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, Chin)
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2018年第5期390-394,共5页
Chinese Journal of Radiology
基金
国家重点研发计划（2016YFC1300300）
国家自然科学基金（81641069,81271542）
