双能量CT肺灌注成像诊断肺栓塞

Dual Energy CT Lung Perfusion Imaging in Diagnosis of Pulmonary Embolism

目的:探讨肺栓塞(PE)的双能量CT肺灌注成像(DEPI)表现及其诊断价值。方法:42例疑似PE患者进行DEPI扫描,以80k V的数据得到CTPA图像,采用Lung PBV软件后处理得到DEPI图像,观察CTPA图像上PE的位置、类型以及DEPI图像肺灌注缺损的位置及形态,以肺段为单位对PE的类型及灌注缺损的类型进行相关性分析,以CTPA为标准分析以肺叶及肺段为单位DEPI诊断PE的效率。结果:840个肺段中CTPA检出178个肺段有PE,DEPI检出186个肺段有灌注缺损,部分型PE主要为斑点状、斑片状灌注缺损或无缺损,完全型PE则以段或亚段分布的灌注缺损为主,且栓塞与灌注缺损类型存在相关性(P<0.05)。以CTPA为标准,以肺叶及肺段为单位DEPI诊断PE的敏感度、特异度、KAPPA系数值分别为89.06%、73.97%、0.555,79.77%、93.35%、0.719。结论:DEPI可以一次扫描获得肺组织的解剖与功能信息,有助于PE的诊断。

Purpose： To explore the value of dual energy CT lung perfusion imaging （DEPI） in diagnogig of pulmonary embolism. Methods： Dual energy CT lung perfusion were performed in 42 patients with suspected PE, DEPI images were obtained with 80kv and 140kv date using lung PBV software, CTPA images were obtained with 80kv data. The location, number and type of PE of CTPA and DEPI were recorded respectively. Correlation analysis was done between the type of PE and perfusion defect in a per segment basis. Taken CTPA as reference, sensitivity, specificity and KAPPA value were measured in a per segment and lobe basis. Results： PE was detected in 178 segments by CTPA, and perfusion defect was detected 186 segments by DEPI. Sensitivity, specificity and KAPPA value of DEPI in diagnosis of PE were 89.06%, 73.97%, 0.555, 79.77%, 93.35% and 0.719 in a per segment and lobe basis respectively. Partial PE showed partial perfusion defects or normal, complete PE showed segmental or sub-segmental shaped perfusion defects. Conclusion： The combination of DEPI and CTPA can be used to obtaine anatomical and functional information about lung tissue, is useful for diagnosis of PE.