双能量CT肺灌注及血管成像与核素肺通气灌注成像诊断肺栓塞的对照研究

Comparative study of dual-energy CT pulmonary angiography and lung perfusion with pulmonary perfusion scintigraphy in the diagnosis of pulmonary embolism

目的 通过与核素肺通气灌注显像比较,评价双能量CT肺血管成像（DE-CTPA）及双能量CT肺灌注成像（DE-CTLP）技术诊断肺栓塞的能力.方法 比较50例临床怀疑肺栓塞的患者DE-CTPA、DE-CTLP及核素肺通气灌注显像结果,以非线性相关检验比较DE-CTPA显示肺血管腔内充盈缺损与DE-CTLP显示灌注缺损之间的相关性,以核素为参考标准,应用一致性检验方法（Kappa检验）对照分析两者之间的一致性及DE-CTLP诊断肺栓塞的敏感性和特异性.结果 （1）50例临床怀疑肺栓塞患者中,4例CT图像质量差,不能评价.余46例共920个有效肺段中,DE-CTPA显示262个肺段肺血管腔内充盈缺损,DE-CTLP显示266个肺段明确灌注缺损.核素肺通气灌注扫描显示268个肺段灌注与通气不匹配.（2）DE-CTLP与DE-CTPA两者间显著相关（r=0.883,P〈0.01） DE-CTLP与核素肺通气灌注显像的一致性良好（Kappa=0.940,P〈0.01） 以核素肺通气灌注成像为诊断参考标准,应用DE-CTLP诊断肺栓塞的阳性预测值95.5%（279/292）,阴性预测值98.3%（641/652）,敏感性96.2%（279/290）,特异性98.0%（641/654）.（3）应用CareDose 4D技术,DE-CTPA和DE-CTLP患者平均射线损伤剂量为（4.37±0.47）mSv.结论 应用DE-CTPA和DE-CTLP技术可以在一次扫描中同时获得常规CT肺血管成像的血管形态学信息和肺实质血流灌注情况,为临床诊断肺栓塞提供直观、有效的综合影像信息.

Objective To investigate the diagnostic value of dual-energy CT pulmonary angiography （DE-CTPA） and dual-energy CT lung perfusion （DE-CTLP） in the assessment of pulmonary embolism comparing with pulmonary ventilation-perfusion scintigraphy. Methods Fifty patients suspected of PE （26 males, 24 females） underwent both DE-CTPA, DE-CTLP and pulmonary ventilation-perfusion scintigraphy. The results were compared and the correlation between the intravascular clots in DE-CTPA and the perfusion defects in DE-CTLP was analyzed. The sensitivity, specificity and accuracy of DE-CTLP for PE were assessed according to scintigraphic results which was considered as a ＂gold＂ standard. Result （ 1 ） Of 50 cases,920 segments in 46 cases were diagnostable, 4 cases were not included because of the poor image quality. lntravascular clots were found in 262 segments on DE-CTPA and perfusion defects in 266 segments were identified on DE-CTLP, while 268 segments were positive on scintigraphy. （2） The perfusion defects on DE-CTLP were correlated well with the clots on CTPA （ r = 0. 883, P 〈 0. 01 ）. The Dual energy CT Lung perfusion imaging had a good consistence with scintigraphy （Kappa = 0. 940, P 〈0. 01 ）. The sensitivity, specificity, positive and negative predictive value were 96. 2% （279/290）, 98.0%（641/654）, 95. 5% （279/292） and 98. 3% （641/652）, respectively. （3）The radiation dose of DE-CTPA and CE-CTLP scan was（4. 37 ± 0. 47） mSv by using CareDose 4D technique. Conclusion DE-CTPA and CE-CTLP can provide pulmonary vascular morphology and parenchyma perfusion information which are useful and valuable for the diagnosis of PE.