Cardiovascular Engineering and Technology ( IF 1.6 ) Pub Date : 2022-12-14 , DOI: 10.1007/s13239-022-00652-0
Daniel E MacDonald 1 , Nicole M Cancelliere 2 , Vitor M Pereira 2, 3 , David A Steinman 1
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Introduction
Overestimation of intracranial aneurysm neck width by 3D angiography is a recognized clinical problem, and has long been a concern for image-based computational fluid dynamics (CFD). Recently, it was demonstrated that neck overestimation in 3D rotational angiography (3DRA) could be corrected via segmentation with upsampled resolution and gradient enhancement (SURGE). Our aim was to leverage this approach to determine whether and how neck overestimation actually impacts CFD-derived hemodynamics.
Materials and Methods
A subset of 17 cases having the largest neck errors from a consecutive clinical sample of 60 was segmented from 3DRA using both standard watershed and SURGE methods. High-fidelity, pulsatile CFD was performed, and a variety of scalar hemodynamic parameters that have been associated with aneurysm growth and/or rupture status were derived.
Results
With a few exceptions, flow and wall shear stress (WSS) patterns were qualitatively similar between neck-overestimated and corrected models. Sac-averaged WSS values were significantly lower after neck correction (p = 0.0005) but were highly correlated with their neck-overestimated counterparts (R2 = 0.98). Jet impingement was significantly more concentrated in the neck-corrected vs. -uncorrected models (p = 0.0011), and only moderately correlated (R2 = 0.61). Parameters quantifying velocity or WSS fluctuations were not significantly different after neck correction, but this reflected their poorer correlations (R2 < 0.4). Nevertheless, for all hemodynamic parameters, median absolute differences were < 26%, and no parameter had more than 5/17 cases with absolute differences > 50%.
Conclusion
Differences in hemodynamics due to neck width overestimation were found to be at most equal to, and often less than, those reported for other sources of error/uncertainty in intracranial aneurysm CFD, such as solver settings or assumed inflow rates.
中文翻译:
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动脉瘤颈部高估对模拟血流动力学的影响相对较小
介绍
通过 3D 血管造影高估颅内动脉瘤颈宽度是一个公认的临床问题,长期以来一直是基于图像的计算流体动力学 (CFD) 的关注点。最近,证明 3D 旋转血管造影 (3DRA) 中的颈部高估可以通过具有上采样分辨率和梯度增强 (SURGE) 的分割来纠正。我们的目标是利用这种方法来确定颈部高估是否以及如何实际影响 CFD 衍生的血液动力学。
材料和方法
使用标准分水岭和 SURGE 方法从 3DRA 中分割出 60 个连续临床样本中颈部误差最大的 17 个病例的子集。执行了高保真、脉动 CFD,并导出了与动脉瘤生长和/或破裂状态相关的各种标量血流动力学参数。
结果
除了少数例外,流动和壁面剪切应力 (WSS) 模式在颈部高估模型和校正模型之间在性质上相似。颈部矫正后 Sac 平均 WSS 值显着降低 ( p = 0.0005),但与颈部高估的对应值高度相关 ( R 2 = 0.98)。射流撞击明显更集中在颈部校正模型与未校正模型中 ( p = 0.0011),并且仅适度相关 ( R 2 = 0.61)。颈部校正后量化速度或 WSS 波动的参数没有显着差异,但这反映了它们较差的相关性 ( R 2 < 0.4)。尽管如此,对于所有血液动力学参数,中位绝对差异均小于 26%,并且没有参数的绝对差异大于 50% 的病例超过 5/17。
结论
由于颈部宽度高估导致的血流动力学差异最多等于,通常小于颅内动脉瘤 CFD 中其他错误/不确定性来源报告的差异,例如求解器设置或假设的流入率。