Aneurysm rupture has been suggested to be related to aneurysm geometry, morphology, and complex flow activity; therefore, understanding aneurysm-specific hemodynamics is crucial. 4D Flow MRI has been shown to be a feasible tool for assessing hemodynamics in intracranial aneurysms with high spatial resolution. However, it requires averaging over multiple heartbeats and cannot account for cycle-to-cycle hemodynamics variations. This study aimed to assess cycle-to-cycle flow dynamics variations in a patient-specific intracranial aneurysm model using tomographic particle image velocimetry (tomo-PIV) at a high image rate under pulsatile flow conditions. Time-resolved and time-averaged velocity flow fields within the aneurysm sac and estimations of wall shear stress (WSS) were compared with those from 4D Flow MRI. A one-way ANOVA showed a significant difference between cardiac cycles (p value < 0.0001); however, differences were not significant after PIV temporal and spatial resolution was matched to that of MRI (p value 0.9727). This comparison showed the spatial resolution to be the main contributor to assess cycle-to-cycle variability. Furthermore, the comparison with 4D Flow MRI between velocity components, streamlines, and estimated WSS showed good qualitative and quantitative agreement. This study showed the feasibility of patient-specific in-vitro experiments using tomo-PIV to assess 4D Flow MRI with high repeatability in the measurements.

动脉瘤破裂被认为与动脉瘤的几何形状、形态和复杂的血流活动有关；因此，了解动脉瘤特异性血流动力学至关重要。4D Flow MRI 已被证明是一种可行的工具，可用于评估具有高空间分辨率的颅内动脉瘤的血液动力学。然而，它需要对多个心跳进行平均，并且无法解释周期到周期的血液动力学变化。本研究旨在使用断层摄影粒子图像测速仪 (tomo-PIV) 在脉动流条件下以高图像速率评估患者特异性颅内动脉瘤模型中循环到循环的流动动力学变化。将动脉瘤囊内的时间分辨和时间平均速度流场以及壁面剪切应力 (WSS) 的估计值与 4D Flow MRI 进行了比较。p值 < 0.0001）；然而，在 PIV 时间和空间分辨率与 MRI 相匹配后，差异并不显着（p值 0.9727）。这种比较表明空间分辨率是评估循环间变异性的主要贡献者。此外，速度分量、流线和估计的 WSS 与 4D Flow MRI 的比较显示出良好的定性和定量一致性。这项研究显示了使用 tomo-PIV 评估具有高重复性测量的 4D Flow MRI的患者特异性体外实验的可行性。