内膜钙化对64层CT血管造影诊断颈动脉狭窄的影响

目的评判内膜钙化对64层CT血管造影(CTA)诊断颈内动脉狭窄的影响。方法选取前循环脑缺血性症状患者106例,CT值≥130Hu定为钙化斑块,同时也将颈内动脉(ICA)的检测结果分为钙化组和非钙化组。以DSA狭窄率的平均值为"金标准",以50%为界,测量CTA的敏感度、特异度、阳性预测值、阴性预测值。结果 ICA狭窄率超过50%时,非钙化斑块组CTA诊断敏感度97.5%、特异度100%、阳性预测值100%、阴性预测值97.9%和Kappa值0.977(P<0.01);钙化斑块组CTA诊断敏感度96.4%、特异度87.5%、阳性预测值84.4%、阴性预测值97.2%和Kappa值0.822(P<0.01)。两组间的特异度和阳性预测值比较,差异有统计学意义(P<0.05)。结论 64层CTA诊断颈内动脉狭窄是可靠的,但它诊断颈内动脉狭窄精确度受到钙化斑块的影响,尚不能代替DSA。

The influence of intima calcification on 64-slice computed tomography angiography in evaluating carotid artery stenosis

Objective To evaluate if influence of intima calcification in evaluating carotid stenosis with 64-slice CT angiography.Methods One hundred and six anterior circulation stroke or TIA patients with interpretable CTA and DSA of the cervical carotid arteries were selected from December 2006 to April 2010.Patients were divided into those with none calcification and calcification by CT density.ICA were also divided as none calcification and calcification by CT density： group A CT Hu≥130（68 artery） and group B CT Hu〈130 Hu（87 artery）.Results When the 50% stenosis was used as the cut-off value in none calcification and calcification,the sensitivity,specificity,negative predictive value（NPV）,the positive predicting value（PPV） and κ value were 97.5%,100%,97.9%,100%,0.977（P〈0.01） and 96.4%,87.5%,97.2%,84.4%,0.822（P〈0.01）,respectively.Conclusion An excellent correlation and high accuracy were demonstrated between CTA and DSA in evaluating carotid stenosis,but its accuracy were influenced by infima calcification.