颈动脉血流动力学的比较评估：患者特异性 CFD 模拟与 4D 血流 MRI 的对比

中文摘要 AI 辅助

壁面剪切应力（WSS）与颈动脉粥样硬化相关，4D 血流 MRI 提供了一种无创的 WSS 估算途径，但 MRI 衍生的斑块表面 WSS 与计算流体动力学（CFD）之间的一致性尚未在大规模队列中得到量化。我们在 120 名患者的 240 条颈动脉中比较了 4D 血流 MRI 与患者特异性 CFD 的峰值收缩期速度和 WSS，其中 CFD 的几何模型和边界条件均源自 MRI。在三个标准化横截面上比较了速度和周向 WSS，并在 149 条狭窄动脉中具有可靠斑块分割的 63 条动脉上比较了斑块表面 WSS。一致性通过 Bland-Altman 分析、与狭窄程度的 Spearman 相关性以及针对斑块表面差异与血流动力学和几何变量的探索性多元回归进行评估。MRI 再现了整体血流特征，但低估了峰值速度，且越靠近颈内动脉远端低估越明显。WSS 差异具有位置依赖性：在颈总动脉中，平均周向 WSS 的平均偏倚很小，而 MRI 遗漏了分叉顶点的较高 WSS，并将斑块表面平均和最大 WSS 分别低估了 $40.9 \pm 28.8\\%$ 和 $44.5 \pm 26.8\\%$；差异（以 Pa 计）随狭窄程度增加而增大（$\rho= 0.47$ 和 $0.50$）。在探索性回归中，CFD 衍生的跨斑块压降是平均 WSS 差异的唯一显著相关因素，而狭窄程度和几何变量与最大 WSS 差异相关。在现有方案下，MRI 衍生的斑块表面 WSS 与 CFD 存在量级和位置依赖性差异，在狭窄更严重的动脉中差异更大，并且在探索性分析中，这些差异与狭窄程度以外的因素相关。

英文摘要

Wall shear stress (WSS) is implicated in carotid atherosclerosis, and 4D flow MRI offers a non-invasive route to its estimation, but the agreement of MRI-derived plaque-surface WSS with computational fluid dynamics (CFD) has not been quantified in a large cohort. We compared peak-systolic velocity and WSS from 4D flow MRI and patient-specific CFD in 240 carotid arteries of 120 patients, with CFD geometries and boundary conditions derived from MRI. Velocity and circumferential WSS were compared at three standardized cross-sections, and plaque-surface WSS in 63 of 149 stenosed arteries with a reliably segmented plaque. Agreement was assessed with Bland-Altman analysis, Spearman correlation with stenosis degree, and exploratory multivariable regression of the plaque-surface discrepancy on hemodynamic and geometric variables. MRI reproduced the broad flow features but underestimated peak velocity, increasingly toward the distal internal carotid artery. WSS disagreement was location dependent: mean circumferential WSS showed little average bias in the common carotid artery, whereas MRI missed the high WSS at the bifurcation apex and underestimated plaque-surface mean and maximum WSS by $40.9 \pm 28.8\%$ and $44.5 \pm 26.8\%$; the difference in Pa increased with stenosis degree ($ρ= 0.47$ and $0.50$). In exploratory regression, the CFD-derived pressure drop across the plaque was the only significant correlate of the mean WSS discrepancy, whereas stenosis degree and geometric variables were associated with the maximum WSS discrepancy. Under the present protocol, MRI-derived plaque-surface WSS showed magnitude- and location-dependent disagreement with CFD, greater in more severely stenosed arteries and, in exploratory analyses, associated with factors beyond stenosis degree.

发表机构

• University of Bern（伯尔尼大学）
• University of Freiburg（弗莱堡大学）

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