肺动脉主干血栓在CT平扫图像上的可见性及其影响因素分析

Visibility of thrombus in the pulmonary trunk on plain CT scan and its influencing factors

摘要:

目的：探讨肺动脉主干血栓在CT平扫图像上的显示情况及其影响因素。方法：回顾性分析2017年6月至2018年10月间经CT肺动脉造影（computed tomographic pulmonary angiography，CTPA）检查证实的79例肺动脉主干栓塞患者的临床及影像学资料。结合CTPA图像，评价肺动脉主干血栓在CT平扫图像上能否显示及其表现特征，同时评价平扫血栓表现与肺血管和心室腔的径线及相关实验室指标间的关系。结果：79例患者中，表现为单纯主干、单纯主干远端及主干合并远端栓塞者分别为6（7.5%）、40（50.6%）和33（41.9%）例。CT平扫图像上，管腔内血栓表现为低、等及高密度者分别为34（43.0%）、23（29.1%）和22（27.9%）例，3组间血栓CT值具有统计学差异[（21.5±6.1） HU vs. （37.9±7.7） HU vs. （63.4±7.0） HU，P=0.000]，而邻近管腔内血液CT值无统计学差异[（45.4±7.9） HU vs. （38.6±5.0） HU vs. （40.7±5.2） HU，P＞0.05]。CTPA图像上，血栓类型以中央型（30例，38.0%）最为常见，其次为锐角附壁型（25例，31.6%）和钝角附壁型（16例，20.2%）。结论：对于可疑肺栓塞患者，当CT平扫图像上肺动脉主干的管腔中央或一侧出现片状高、低密度影时，要高度怀疑血栓栓塞的可能。

Abstract:

Objective：To explore the visibility of thrombus in the pulmonary trunk on plain computed tomography（CT） scan and its influencing factors. Methods：A retrospective analysis was performed on the clinical and radiological data of 79 patients who were diagnosed with thrombus in the pulmonary trunk by CT pulmonary angiography（CTPA） from June 2017 to October 2018. Based on the CTPA results，the visibility and characteristics of thrombus in the pulmonary trunk on plain CT images were evaluated；the rela－tionship of thrombus features on plain CT images with diameters of the pulmonary artery and ventricular cavity and related laboratory indices was evaluated. Results：In the 79 patients，6（7.5%） had simple main trunk embolism，40（50.6%） simple distal trunk embolism，and 33（41.9%） main trunk embolism with distal embolism. According to the plain CT images，34（43.0%），23（29.1%），and 22（27.9%） patients had intravascular thrombus of low，equal，and high densities，respectively. There was a significant difference in the CT value of thrombus between the three groups[（21.5±6.1） HU vs. （37.9±7.7） HU vs. （63.4±7.0） HU，P=0.000]. However，there was no significant difference in the CT value of blood in adjacent vessels between the three groups[（45.4±7.9） HU vs. （38.6±5.0） HU vs. （40.7±5.2） HU，P>0.05]. According to the CTPA images，the most common type of thrombus was central type（30 patients，38.0%），followed by acute angle with the vessel wall（25 patients，31.6%），and obtuse angle with the vessel wall（16 patients，20.2%）. Conclusion：For patients with suspected pulmonary embolism，a high possibility of thromboembolism should be considered when high- or low-density patchy shadows are detected in the center or one side of the pulmonary trunk lumen on plain CT scan.