双能量CT肺灌注成像的定量参数诊断肺栓塞的临床应用价值

目的探讨双能量CT肺灌注成像(DEPI)的定量参数诊断肺栓塞的临床应用价值。方法选取40例疑似肺栓塞行双能量CT扫描并行CTPA及DEPI重建的患者影像资料,以肺段为评价单位,分析PE栓子的部位、栓塞程度以及肺灌注情况,测量感兴趣区的平均CT值及碘含量值与正常灌注区的比值,并进行统计学分析。结果40例患者分为非栓塞组13例,栓塞组24例,其他3例;栓塞组无栓塞肺段(201个)与非栓塞组肺段(200个)的平均CT值比值(t=-1.81,P>0.05)、碘含量比值(t=-1.541,P>0.05)差异无统计学意义;栓塞组栓塞肺段(204个)与无栓塞肺段(201个)的平均CT值比值(t=34.77,P<0.01)、碘含量比值(t=32.07,P<0.01)差异有统计学意义;栓塞组完全栓塞肺段(83个)与部分栓塞肺段(121个)的平均CT值比值(t=-17.54,P<0.01)、碘含量比值(t=-16.27,P<0.01)差异有统计学意义。ROC曲线分析显示DEPI定量参数对肺栓塞具有良好的诊断效能,平均CT值及碘含量值<40.65 HU、1.75 mg/ml临界值时,诊断PE的敏感度分别为96.0%、92.0%,特异度分别为88.6%、90.0%。结论DEPI定量参数能够作为诊断PE的有效指标,具有较高的敏感度和特异度,对PE治疗前后的评估提供更加全面、客观的依据。

The clinical value of quantitative parameters of dual energy lung perfusion imaging in the diagnosis of pulmonary embolism

Objective To explore the clinical value of quantitative parameters of dual energy lung perfusion imaging(DEPI)in the diagnosis of pulmonary embolism(PE).Methods 40 patients with suspected pulmonary embolism underwent dual energy imaging,the images were evaluated with CT pulmonary arteriography and dual energy lung perfusion imaging.All images were based on sub-branches,the location and embolism proportion of PE in CTPA and average CT value and lodine value in DEPI were recorded and analyzed.Results According to CTPA,40 patients were divided into non embolism group(13 cases),embolism group(24 cases)and other 3 cases.There was no significant difference in the ratio of the average CT value(t=-1.81,P>0.05)and the ratio of the iodine value(t=-1.541,P>0.05)between embolism group(sub-branches without embolism)and non embolism group.There were significant differences in the ratio of the average CT value(t=34.77,P<0.01)and the ratio of the iodine value(t=32.07,P<0.01)between the embolism group(sub-branches with embolism)and embolism group(sub-branches without embolism).There were significant differences in the the ratio of the average CT value(t=-17.54,P<0.01)and the ratio of the iodine value(t=-16.27,P<0.01)between sub-branches with the complete embolism and sub-branches with partial embolism.ROC curve analyses demonstrated moderator discriminatory power for using the quantitative parameters of DEPI to differentiate patients with and without PE.With the average CT value and iodine content value<40.65 HU and 1.75 mg/ml as the threshold for diagnosis PE,the sensitivity and specificity were 96.0%,92.0%and 88.6%,90.0%respectively.Conclusion The quantitative parameters of DEPI can be used as an effective index to diagnose PE,with high sensitivity and specificity,providing a more comprehensive and objective basis for the evaluation of PE before and after treatment.