中文摘要：

目的 利用多排螺旋CT（MDCT）的CT肺动脉造影（CTPA）图像及超声流态数据与流体力学软件相结合初步模拟正常人主肺动脉及左右肺动脉分支内流动状态。方法选择正常胸部心电门控CTPA图像，分别进行心脏收缩期及舒张期薄层多平面重建，在InSpace肺动脉重建坐标图中做手动分割，用GAMBIT软件生成网格，将超声测量数据导入Fluent软件进行数值计算和流态模拟。结果正常肺动脉分支不同心动周期流动状态不同，收缩期较舒张期压力高，流速快，右肺下叶动脉承受双期压差最大，段动脉双期流速差别不大。结论右肺下叶动脉是肺动脉压力升高是受累较早者；利用CTPA图像结合相关模拟软件研究肺动脉分支内血流变化是可行的。

英文摘要：

Objective To simulate the flow condition in the main pulmonary artery and the branches of left and right pulmonary arteries by combining the images from CT pulmonary angiography （CTPA） by multiple detectors computed tomography （MDCT） and the flow condition data from ultrasonic cardiography. Methods The normal enhanced chest CTPA images with ECG-gating from 25 persons undergoing physical examination, 21 males and 4 females, aged 39, underwent thin-slice multiple plane reconstruction in diastolic and systolic periods respectively. These images were stored in the InSpace software. On the base of coordinates GAMBIT software was used to generate the nodes and meshes. FLUENT software was used to simulate the blood flow speed and pressure field distribution. Results The pressure levels of the main pulmonary artery and the branches of left and right pulmonary arteries were higher during the systolic period. The blood flow velocity was faster during the systolic period too. The right lower lobe artery endured the most significant pressure during both systolic and diastolic periods. However, there were not significant differences in pressure and blood flow velocity between the systolic and diastolic periods in the segmental arteries. Conclusion The right lower lobe artery is the first part to be affected when the pulmonary pressure rises. It is feasible to study the changes of the flow condition in the branches of pulmonary artery through combining CTPA images and relevant sofiwares.