BACKGROUND Hemodynamic patterns have been associated with cerebral aneurysm instability. For patient-specific computational fluid dynamics (CFD) simulations, the inflow rates of a patient are typically not known. The aim of this study was to analyze the influence of inter- and intra-patient variations of cerebral blood flow on the computed hemodynamics through CFD simulations and to incorporate these variations into statistical models for aneurysm rupture prediction. METHODS Image data of 1820 aneurysms were used for patient-specific steady CFD simulations with nine different inflow rates per case, capturing inter- and intra-patient flow variations. Based on the computed flow fields, 17 hemodynamic parameters were calculated and compared for the different flow conditions. Next, statistical models for aneurysm rupture were trained in 1571 of the aneurysms including hemodynamic parameters capturing the flow variations either by defining hemodynamic "response variables" (model A) or repeatedly randomly selecting flow conditions by patients (model B) as well as morphological and patient-specific variables. Both models were evaluated in the remaining 249 cases. RESULTS All hemodynamic parameters were significantly different for the varying flow conditions (p < 0.001). Both the flow-independent "response" model A and the flow-dependent model B performed well with areas under the receiver operating characteristic curve of 0.8182 and 0.8174 ± 0.0045, respectively. CONCLUSIONS The influence of inter- and intra-patient flow variations on computed hemodynamics can be taken into account in multivariate aneurysm rupture prediction models achieving a good predictive performance. Such models can be applied to CFD data independent of the specific inflow boundary conditions.

中文翻译：

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将患者入院条件的可变性纳入动脉瘤破裂评估的统计模型中。

背景技术血液动力学模式已经与脑动脉瘤不稳定相关。对于特定于患者的计算流体动力学（CFD）模拟，通常不知道患者的流入率。这项研究的目的是通过CFD模拟分析患者之间和患者内部的大脑血流变化对计算的血流动力学的影响，并将这些变化纳入统计模型以预测动脉瘤破裂。方法将1820个动脉瘤的图像数据用于特定于患者的稳定CFD模拟，每种情况有9种不同的流入率，以捕获患者之间和患者内部的流量变化。基于计算出的流场，计算了17种血液动力学参数，并比较了不同的流动条件。下一个，在1571年，对动脉瘤破裂的统计模型进行了训练，包括通过定义血液动力学“响应变量”（模型A）或由患者（模型B）反复随机选择血流状况以及形态学和患者-来捕获血流变化的血流动力学参数。具体变量。其余249例均评估了这两种模型。结果对于不同的血流条件，所有血液动力学参数均存在显着差异（p <0.001）。与流量无关的“响应”模型A和与流量无关的模型B都在接收器工作特性曲线下的面积分别为0.8182和0.8174±0.0045的情况下表现良好。结论在实现良好预测性能的多变量动脉瘤破裂预测模型中，可以考虑患者之间和患者内部流量变化对计算的血流动力学的影响。这样的模型可以应用于CFD数据，而与特定的流入边界条件无关。