双源CT双能量肺灌注成像对肺栓塞的诊断和临床应用价值

目的:探讨双源CT双能量肺灌注成像对肺动脉栓塞的诊断和临床应用价值。方法:对疑诊肺动脉栓塞的78名患者行双源CT肺动脉成像双能量扫描,数据经后处理得到肺动脉血管图像(CTA)和肺灌注图像(PBV)。两位医师对PBV图像进行质量评价和分型,同时观察CTA图像有无栓塞以及栓塞的部位、程度。分析PBV图像的表现与CTA图像、肺部异常改变的关系。用Kappa系数检验两位观察者对PBV图像质量评价和分型的一致性,计算PBV图像诊断肺栓塞的敏感度、特异度、阳性预测值和阴性预测值。结果:两位医师对肺灌注图像质量的分级以及肺灌注图像的分型一致性极强,K值分别为0.87、0.80,P值均<0.01。PBV图像诊断肺栓塞的敏感度为95.30%,特异度为56.40%,阳性预测值为70.70%,阴性预测值为91.20%。对于完全栓塞的患者,其敏感度和特异度均为100%。结论:双源CT双能量肺灌注成像能够显示肺动脉栓塞导致肺血流改变的肺灌注异常。

Dual energy perfusion imaging using dual source CT in the diagnosis and clinical application of pulmonary embolism

Objective：To investigate the value of dual energy pulmonary perfusion imaging using dual source CT in the diagnosis and clinical application of pulmonary artery embolism（PE）.Methods：Seventy-eight consecutive patients suspected of having PE underwent CT pulmonary arteriography with dual-energy technique on a dual source CT scanner.CT pulmonary arteriography（CTPA） and perfusion blood volume（PBV） images after post-processing of the raw data were obtained.Evaluation of the PBV image quality and typing of PE were performed by two radiologists as well as to observe the presence,location,extent of PE.The PBV appearances and its relationship with CTA images as well as pulmonary parenchyma abnormities were analyzed.The consistency of the 2 observers in evaluating the PBV image quality and typing were examined by Kappa value.The sensitivity,specificity,positive predictive value（PPV） and negative predictive value（NPV） of PBV images for the diagnosis of PE were calculated.Results：The ranking of PBV image quality and typing showed very good agreement between two observers,the K value was 0.87 and 0.80,respectively（P0.01）.The sensitivity,specificity,PPV and NPV of PVB for the diagnosis of PE was 95.3%,56.4%,70.7%,91.2%,respectively.The sensitivity and specificity was 100% respectively for patients with complete PA occlusion.Conclusion：Abnormalities caused by pulmonary blood flow changes induced by PE could be displayed by PBV with dual energy pulmonary perfusion imaging on dual source CT.