Improving Computation of Cardiovascular Relative Pressure Fields From Velocity MRI
Improving Computation of Cardiovascular Relative Pressure Fields From Velocity MRI
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DOI：
10.1002/jmri.21775
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发表时间：
2009-07-01
影响因子：
4.4
通讯作者：
Farneback, Gunnar
中科院分区：
文献类型：
--
作者：
Ebbers, Tino;Farneback, Gunnar
目的：评价基于Galerkin粗化的压力泊松方程（PPE）多网格求解器，该求解器直接在指定域上工作，用于计算速度MRI数据的相对压力场。材料和方法：我们将提出的结构定义泊松求解器与其他流行的泊松求解器进行了比较，这些泊松求解器使用合成的和体外的模型来处理未修改的矩形和修改的准矩形区域，其中压力场的数学解是已知的，以及活体MRI主动脉血流动力学的速度测量。结果：三种PPE求解器在凸计算域上都给出了准确的结果。在更复杂的域（如c形）上使用矩形或准矩形域，揭示了对压力幅值的系统性低估，而所提出的PPE求解器直接在指定域上工作，提供了相对压力场的准确估计。结论：常用的准矩形计算域迭代方法可能导致压力振幅的显著系统低估。我们建议使用Galerkin粗化的基于多网格的PPE求解器，它直接作用于结构定义的计算域。该求解器为简单和复杂几何形状提供了相对压力场的准确估计，并在执行速度方面有了额外的显着改进。
Purpose: To evaluate a multigrid-based solver for the pressure Poisson equation (PPE) with Galerkin coarsening, which works directly on the specified domain, for the computation of relative pressure fields from velocity MRI data.Materials and Methods: We compared the proposed structure-defined Poisson solver to other popular Poisson solvers working on unmodified rectangular and modified quasirectangular domains using synthetic and in vitro phantoms in which the mathematical solution of the pressure field is known, as well as on in vivo MRI velocity measurements of aortic blood flow dynamics.Results: All three PPE solvers gave accurate results for convex computational domains. Using a rectangular or quasirectangular domain on a more complicated domain, like a c-shape, revealed a systematic underestimation of the pressure amplitudes, while the proposed PPE solver, working directly on the specified domain, provided accurate estimates of the relative pressure fields.Conclusion: Popular iterative approaches with quasirectangular computational domains can lead to significant systematic underestimation of the pressure amplitude. We suggest using a multigrid-based PPE solver with Galerkin coarsening, which works directly on the structure-defined computational domain. This solver provides accurate estimates of the relative pressure fields for both simple and complex geometries with additional significant improvements with respect to execution speed.