目的研究双源CT双能量成像(DEPI)技术诊断肺栓塞的应用价值。方法回顾性分析我院2010年3月~2014年2月临床疑诊肺栓塞的患者95例应用双源CT进行肺动脉成像(CTPA)扫描,所得扫描图像经专门软件处理得到CTPA、DEPI图像及两种能量成像的融合图像,将CTPA上所示肺动脉内栓子的数量、位置与对应肺组织灌注状态相对照,计算DEPI诊断肺栓塞的敏感性、特异性、阴性预测值和阳性预测值。结果以肺叶为评价单位,DEPI检出灌注缺损或稀疏47个,CTPA检出相应的血管栓塞50个,符合率为94.0%;以肺段为评价单位,DEPI共检出145个肺段有灌注缺损或降低,CTPA检出156个相应肺段血管栓子,符合率为93.0%;以肺亚段为评价单位,DEPI共检出81个肺段有灌注缺损或降低,CTPA检出103个相应肺亚段血管栓子,符合率为79.0%。DEPI诊断PE的敏感性、特异性、阴性预测值(NPV)和阳性预测值(PPV)分别为94.0%、83.0%、94.0%和89.0%;kappa值为0.82。结论双源CT双能量成像能敏感地显示肺栓塞所致的灌注缺损或稀疏,还可弥补CTPA显示远段肺栓子的不足,且可同时提供功能和解剖信息,提高诊断肺栓塞的准确性。
Objective To study the diagnostic value of dual source CT dual energy perfusion imaging ( DEPI} for pulmonary embolism. Methods A retrospective analysis of clinical data was conducted in 95 pa- tients with a clinical diagnosis of pulmonary embolism suspected who were admitted in Nanshan hospital from March 2010 to February 2014. All of them underwent dual energy imaging. The images were evaluated with lung PBV software on the workstation, then CT pulmonary angiography ( CTPA ) , DEPI and fusion image were obtained. The number and location of PE in DEP I and CTPA were recorded and analyzed. The sensi- tivity, specificity, positive predictive value I PPV) and negative predictive value { NPV ) of DEPI images for the diagnosis of PE were calculated. Results To lung as evaluation unit, the DEPI detection perfusion defect or sparse 47, CTPA checked out the corresponding vascular embodiment 50, the coincidence rate is 94.0%, Pulmonary segments as evaluation unit, the DEPI detected 145 lung segment have perfusion defects or reduction, and the CTPA detected 156 embolus coincidence rate was 93.0%. Pulmonary subsegment as e- valuation unit, DEPI detected 81 lung subsegment have perfusion defects or reduction, and the CTPA detec- ted 103 embolus coincidence rate was 79.0%. The sensitivity, specificity, PPV and NPV of DEPI for the di- agnosis of PE was 94.0% ,83.0% ,94.0% ,89.0% , the K value was 0.82. Conclusion the dual source CT dual energy perfusion imaging can sensitively display pulmonary embolism caused by perfusion defects or sparse, make up for the CTPA show distal pulmonary embolus deficiency, and can also provide functional and anatomical information, improve the accuracy of diagnosis of pulmonary embolism.