双源CT肺动脉造影在慢性肺栓塞中的应用价值

The application of dual-source CT pulmonary angiography in chronic pulmonary embolism

目的探讨双源CT肺动脉造影诊断慢性肺栓塞的影像特征及临床应用价值。方法选择75例行双源CT肺血管造影检查的患者,在轴位图像基础上,结合多平面重建(MPR)、最大密度投影(MIP)、容积再现(VR)等后处理技术,对CTPA图像进行综合分析。结果以CTPA诊断肺栓塞的标准确诊慢性肺栓塞26例,慢性肺栓塞的CTPA直接征象表现为:(1)肺动脉管腔内偏心性低密度充盈缺损,栓子与管壁形成钝角5例;(2)血管内壁不光整7例;(3)血管腔内边缘模糊的低密度充盈缺损3例;(4)管腔缩小5例;(5)管腔完全堵塞,无强化2例;(6)肺动脉分支减少4例。肺内间接征象表现为局部肺纹理稀疏纤细,或磨玻璃样改变,呈"马赛克"征、胸膜增厚、胸腔积液,两肺下叶盘状不张、不规则或楔形肺梗死、"肺少血"征、肺动脉高压、右室增大伴或不伴室间隔偏移、心包积液、支气管动脉扩张、同侧支气管扩张。结论双源CT肺动脉造影是诊断慢性肺栓塞的快速、无创的检查方法,根据直接征象能较准确地对慢性肺栓塞进行诊断,对临床治疗具有一定指导意义。

Objective To investigate the value of dual-source CT pulmonary angiography in imaging features and clinical application of chronic pulmonary embolism.Methods 75 cases with dual-source CT pulmonary angiography were collected.The methods which based on the axial images combined with the multi planar reconstruction（MPR）,the maximum density projection（MIP）,volume rendering（VR）and other postprocessing technique were used in order to integrating analysis of CTPA images.Results According to CTPA diagnostic criteria of pulmonary embolism,26 cases were diagnosed as chronic pulmonary embolismand CTPA showed the direct signs were：（1）5cases diagnosed as Pulmonary artery lumen eccentric low density filling defect,emboli and vessel wall forms an obtuse angle.（2）7cases with unsmoothed vascular wall.（3）5cases with narrowed vascular lumen.（4）2cases with completely blocked vascular lumen without enhancement.（5）4cases with decreased pulmonary artery branches.（6）3cases with edge blur low density filling defect within the blood vessel cavity.The indirect signs of lung included the＂mosaic＂sign which appeared as localized reduced lung marking,or ground-glass-like changes,pleural thickening,pleural effusion,plate-like atelectasis at two lower lungs,irregular or wedge pulmonary infarction,Westermark′s sign,Pulmonary Hypertension,enlarged right ventricle with or without displacement of interventricular septum,pericardial effusion,bronchial artery dilatation,Ipsilateral bronchial dilation.Conclusion The dual-source CT pulmonary angiography is a quick,nonivasive modality in the detection pulmonary embolism,according to the direct signs chronic pulmonary embolism can be correctly diagnosed,and has a certain guiding significance for clinical treatment.