应用全模型迭代重建技术的低剂量冠脉CTA在疑似冠心病患者中诊断价值的初步研究

A preliminary study on the diagnostic value of iterative model reconstruction technique combined with low-dose coronary CTA in patients with suspected coronary heart disease

目的:评估应用全模型迭代重建(IMR)技术的低剂量冠脉CTA显示冠状动脉的图像质量及其对疑似冠心病患者冠脉狭窄的诊断价值。方法:回顾分析我院疑似冠心病并接受冠脉CTA及冠状动脉造影(CAG)检查的患者80例。采用4分法对冠脉各主支进行主观质量评分。以CAG显示冠脉管腔直径缩小超过50%为阳性标准,分别在冠脉节段、主支水平分析冠脉CTA诊断冠脉狭窄的灵敏度、特异度、阳性预测值(PPV)、阴性预测值(NPV)及准确度,将患者按Agaston积分分成两组(A组<400,B组≥400),比较两组间诊断效能的差异。结果:在节段水平上,98.1%的冠脉图像质量合格,冠脉CTA诊断冠脉狭窄的灵敏度、特异度、PPV、NPV及准确度分别为93.2%、98.0%、91.3%、98.4%、97.1%;在主支水平上,96.6%的冠脉图像质量合格,冠脉CTA诊断冠脉狭窄的灵敏度、特异度、PPV、NPV及准确度分别为84.6%、93.0%、88.9%、90.1%、89.6%;A、B两组之间在特异度、PPV和准确度上存在显著差异(99.2%&91.8%,95.7%&84.2%,97.9%&93.7%,P<0.05)。结论:应用IMR技术的低剂量冠脉CTA检查可获得满意的图像质量,对冠脉狭窄具有较高的诊断准确性,但对严重钙化的血管节段的诊断尚有局限性。

Objective:To evaluate the image quality of low-dose coronary CTA combined with iterative model reconstruction(IMR)in coronary arteries and its diagnostic value for coronary stenosis in patients with suspected coronary heart disease.Methods:Eighty patients with suspected coronary heart disease who underwent coronary CTA and the catheter coronary angiography(CAG)in our hospital were analyzed retrospectively.The image quality of each coronary artery was divided into 4 grades.Coronary angiography showing coronary artery luminal diameter reduction>50%as positive standard,the sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV)and accuracy of coronary CTA in the diagnosis of coronary artery stenosis were analyzed at the level of coronary artery segment and main artery.Patients were divided into two groups according to the Agaston score(group A<400,group B≥400).The difference in diagnostic efficacy between the two groups was compared.Results:At the segment level,98.1%of the coronary images were qualified,and the sensitivity,specificity,PPV,NPV and accuracy of CTA were 93.2%,98.0%,91.3%,98.4%and 97.1%respectively.At the level of main artery,96.6%of coronary images were qualified,and the sensitivity,specificity,PPV,NPV and accuracy of CTA were 84.6%,93.0%,88.9%,90.1%and 89.6%,respectively.There were significant differences in specificity,PPV and accuracy between groups A and B(99.2%&91.8%,95.7%&84.2%,97.9%&93.7%,P<0.05).Conclusions:Low-dose coronary CTA combined with IMR can obtain satisfactory image quality and has high diagnostic accuracy for coronary artery stenosis.However,the diagnosis of severely calcified segments is still limited.