Assessment of the accuracy of MRI wall shear stress estimation using numerical simulations
Assessment of the accuracy of MRI wall shear stress estimation using numerical simulations
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DOI：
10.1002/jmri.23610
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发表时间：
2012-07-01
影响因子：
4.4
通讯作者：
Ebbers, Tino
中科院分区：
文献类型：
--
作者：
Petersson, Sven;Dyverfeldt, Petter;Ebbers, Tino
目的：探讨MRI测量室壁切应力（WSS）的准确性。具体而言，研究不同参数的影响以及MRI WSS估计值是否与实际WSS单调相关。材料与方法：利用数值模拟研究了基于相衬（PC）MRI速度映射、傅立叶速度编码（FVE）和体素内速度标准差映射的方法估计WSS的准确性。在一定范围内的WSS值的空间分辨率，速度编码，壁分割，体素位置的影响进行了研究。结果：WSS估计被认为是敏感的参数设置一般和空间分辨率，特别是。所有方法都低估了WSS，但基于FVE的方法除外，该方法对相对于壁的体素位置非常敏感。使用基于PC的WSS估计与壁分割的方法显示对于低WSS是准确的，但对分割误差敏感。结论：即使在没有噪声的情况下并且对于相对简单的速度分布，MRI WSS估计也不能总是被假设为与实际WSS线性地或甚至单调地相关。无法解析高WSS值，估计值取决于参数设置。然而，区分低和中等WSS的区域可能是可行的。J.磁共振Imaging 2012; 36：128138. (c)2012 Wiley Periodicals，Inc.
Purpose: To investigate the accuracy of wall shear stress (WSS) estimation using MRI. Specifically, to investigate the impact of different parameters and if MRI WSS estimates are monotonically related to actual WSS. Materials and Methods: The accuracy of WSS estimation using methods based on phase-contrast (PC) MRI velocity mapping, Fourier velocity encoding (FVE) and intravoxel velocity standard deviation mapping were studied using numerical simulations. The influence of spatial resolution, velocity encoding, wall segmentation, and voxel location were investigated over a range of WSS values. Results: WSS estimates were found to be sensitive to parameter settings in general and spatial resolution in particular. All methods underestimated WSS, except for the FVE-based method, which instead was extremely sensitive to voxel position relative to the wall. Methods using PC-based WSS estimation with wall segmentation showed to be accurate for low WSS, but were sensitive to segmentation errors. Conclusion: Even in the absence of noise and for relatively simple velocity profiles, MRI WSS estimates cannot always be assumed to be linearly or even monotonically related to actual WSS. High WSS values cannot be resolved and the estimates depend on parameter setting. Nevertheless, distinguishing areas of low and moderate WSS may be feasible. J. Magn. Reson. Imaging 2012;36:128138. (c) 2012 Wiley Periodicals, Inc.