双能CT肺灌注成像评价肺栓塞栓子形态与功能改变的相关性研究

Evaluation of embolic morphology and functional changes in pulmonary embolism by dual source computed tomography pulmonary angiography

目的采用双源计算机体层摄影(DSCT)双能量肺灌注成像诊断肺动脉栓塞(PE),探讨栓塞部位及形态与双能量肺灌注的相关性。方法收集临床怀疑PE,行DSCT双能量肺灌注成像患者120例。(1)分析PE部位及分型;(2)分析PE部位及分型与双能量肺灌注灌注缺损类型的比较;(3)分析纵隔窗肺动脉增强图像与肺灌注图像诊断PE的吻合性,以及肺灌注图像与肺窗图像诊断PE肺内灌注改变的吻合性。结果 (1)从PE发生部位分析,右侧PE的比例高于左侧肺动脉,肺叶动脉较左、右肺动脉干多,双下肺动脉较双上肺动脉多;从形态上分析,以中心型和完全闭塞型居多,附壁型次之,不规则型及马鞍型较少;(2)在不同类型的肺动脉干PE中,完全型易发生于全肺或肺叶灌注缺损,附壁型或中心型常出现肺叶或段灌注缺损;若PE发生在肺叶或肺段,则完全型多出现肺叶或段灌注缺损,而附壁型或中心型多出现肺段或亚段灌注缺损或无灌注缺损;若PE发生在亚段,则多见亚段灌注缺损或无灌注缺损;(3)纵隔窗肺动脉增强图像与肺灌注图像诊断PE的吻合性好,肺灌注图像与肺窗图像诊断PE肺内灌注改变的吻合性差。结论肺灌注成像与PE部位及形态具有一定的相关性,DSCT双能量肺灌注成像能协助诊断PE。

Objective To diagnose pulmonary embolism （PE） with dual source CT （DSCT） dual energy perfusion imaging, and to explore the relationships of the positions and morphology of the pulmonary emboli with dual energy perfusion imaging. Methods DSCT dual energy perfusion imaging was performed in 120 cases suspected as PE. The pulmonary embolus position and types were analyzed and compared with the types of perfusion defects. The coincidence of pulmonary artery enhanced scanning in mediastinum window and pulmonary perfusion imaging in diagnoses of PE and PE pulmonary perfusion changes were analyzed. Results Firstly, a series of analysis of pulmonary embolus position revealed that the embolism rate of right pulmonary artery was higher than that of left pulmonary artery, the embolism rates of lobar arteries were higher than those of the left and right pulmonary trunks, the embolism rates of the pulmonary arteries in the lower lobes were higher than those of the pulmonary arteries in the upper lobes. The morphological assessment of pulmonary emboli showed that central type and complete occlusion type were in the majority,followed by mural type, and irregular type and saddle type were in the minority. Secondly, among the types of pulmonary trunk emboli, the complete occlusion type frequently occurred in the whole lung or lobar perfusion defects, however, the central or mural type more often occurred in pulmonary lobar or segmental perfusion defects. If PE occurred in pulmonary lobe or segment, the complete occlusion type mostly appeared in pulmonary lobar or segmental perfusion defects, while the mural type or center type largely appeared in pulmonary segmental or subsegmental perfusion defects or the lungs without perfusion defect. If PE occurred in the subsegments of the lungs, there was usually subsegmental perfusion defect or no perfusion defect. Thirdly, the pulmonary enhanced scanning in mediastinum window and pulmonary perfusion imaging were in good coincidence for diagnosis of pulmonary embolism, but in bad coincidence for diagnosis of PE pulmonary perfusion changes. Conclusions Pulmonary perfusion imaging is related with the locations and shapes of pulmonary emboli. DSCT dual energy pulmonary perfusion imaging can be used to diagnose pulmonary embolism.