颅内动脉瘤4D Flow MRI与CFD血流动力学参数测量的对比研究

目的对比研究4D Flow MRI和计算流体动力学(computational fluid dynamics,CFD)对颅内动脉瘤的血液流速测量结果,比较分析两种技术方法之间的差异。材料与方法本研究取4例颅内动脉瘤患者,分别做4D Flow MRI扫描和CFD仿真,将两种方法得到的速度结果进行对比研究。根据流速计算并显示4个病例的三维血液流动迹线(Pathline);提取动脉瘤颈部平均血流速度并计算两者之间的归一化均方根误差(normalized root mean square error,NRMSE)和线性相关系数(R~2);最后比较动脉瘤最大截面处的速度分布图。结果 4D Flow MRI和CFD对比结果显示,血液在载瘤动脉和瘤体内部的流动状态相似。瘤颈部平均流速符合良好。4例动脉瘤颈部平均流速的NRMSE均值为0.08992(0.10208、0.10270、0.04242、0.11248),R2均值为0.95958(0.9735、0.9316、0.9920、0.9412)。同时,在动脉瘤最大横截面内,4D Flow MRI和CFD速度分布的整体差异较大,但仍显示出一致的高流速区域分布。结论 4D Flow MRI的测量结果和CFD的计算结果之间具有较好的一致性,在局部存在一定的差异,需要设计体外实验进一步验证。

Hemodynamic parameters comparison between 4D Flow MRI and computational lfuid dynamics for intracranial aneurysms

Objective:To compare the results of 4D Flow MRI and computational lfuid dynamics (CFD).Materials and Methods:In this study, 4 patients with intracranial aneurysms (IA) were selected, all of whom underwent both 4D Flow MRI scan and CFD simulation. Two sets of velocity data were analyzed and compared. 3D pathlines were calculated and visualized based on velocity data. Mean velocity proifles at IAs’ neck contour were obtained and normalized root mean squared error(NRMSE) as well as R-squared(R2) value were calculated and compared. At last, velocity distribution on maximum cross section slice were demonstrated.Results:This study shows 3D pathlines of 4D Flow MRI and CFD look similar to each other. Average velocity on IA’s neck contour are consistent. NRMSE values are 0.08992(0.10208, 0.10270, 0.04242, 0.11248). R2 values are 0.95958(0.9735, 0.9316, 0.9920, 0.9412). In maximum cross setion of IA, velocity distributions demonstrate similar features in general.Conclusion:There exists a strong linear correlation between 4D Flow MRI measurement and CFD simulation, but also some disagreements in detail. It’s necessary to undertake in vitro phantom experiments to investigate in detail.