IMAG, Univ Montpellier, CNRS, Montpellier, France.
ALARA Expertise, Strasbourg, France.
NMR Biomed. 2019 May;32(5):e4063. doi: 10.1002/nbm.4063. Epub 2019 Feb 12.
Several well-resolved 4D Flow MRI acquisitions of an idealized rigid flow phantom featuring an aneurysm, a curved channel as well as a bifurcation were performed under pulsatile regime. The resulting hemodynamics were processed to remove MRI artifacts. Subsequently, they were compared with CFD predictions computed on the same flow domain, using an in-house high-order low dissipative flow solver. Results show that reaching a good agreement is not straightforward but requires proper treatments of both techniques. Several sources of discrepancies are highlighted and their impact on the final correlation evaluated. While a very poor correlation (r = 0.63) is found in the entire domain between raw MRI and CFD data, correlation as high as r = 0.97 is found when artifacts are removed by post-processing the MR data and down sampling the CFD results to match the MRI spatial and temporal resolutions. This work demonstrates that, in a well-controlled environment, both PC-MRI and CFD might bring reliable and correlated flow quantities when a proper methodology to reduce the errors is followed.
对一个具有动脉瘤、弯曲通道和分叉的理想化刚性流模型进行了多次良好分辨率的 4D Flow MRI 采集，这些采集都是在脉动状态下进行的。对得到的血液动力学数据进行处理以去除 MRI 伪影。然后，将其与在相同流场域上使用内部高阶低耗散流求解器计算的 CFD 预测进行比较。结果表明，要达到良好的一致性并不简单，需要对两种技术进行适当的处理。强调了几个差异源，并评估了它们对最终相关性的影响。虽然在整个域中，原始 MRI 和 CFD 数据之间的相关性非常差（r = 0.63），但是通过对 MR 数据进行后处理并对 CFD 结果进行下采样以匹配 MRI 的空间和时间分辨率，可以得到高达 r = 0.97 的高度相关性。这项工作表明，在控制良好的环境中，当遵循适当的减少误差的方法时，PC-MRI 和 CFD 都可以提供可靠且相关的流动量。
