Liu Linfeng, Li Zhuhao, Xiao Weiping, Yang Yibing, Yan Yan, Bai Lu, Quan Lingzhi, Qi Tiewei, Liang Feng
Department of Neurosurgery, Sun Yat-sen University First Affiliated Hospital, Guangzhou 510060, China.
Department of Radiology, Sun Yat-sen University First Affiliated Hospital, Guangzhou 510060, China.
Diagnostics (Basel). 2024 Dec 3;14(23):2722. doi: 10.3390/diagnostics14232722.
The mechanism of aneurysm wall enhancement (AWE) in middle cerebral artery (MCA) bifurcation aneurysms on vessel wall magnetic resonance imaging (VW-MRI) remains unclear. We aimed to explore the morphologically related hemodynamic mechanism for the AWE of MCA bifurcation aneurysms. Patients with unruptured MCA bifurcation aneurysms undergoing VW-MRI were enrolled. Logistic regression analyses were performed to determine the risk factors for AWE. Based on the results of retrospective analyses, bifurcation aneurysm silicone models with a specific aspect ratio (AR) were designed and underwent VW-MRI with different inlet velocities. Computational fluid dynamics (CFD) analyses were conducted on both silicone models and patients' aneurysms. A total of 104 aneurysms in 95 patients (mean age 60; 34 males) were included for baseline analysis and morphological analysis. Logistic regression analysis indicated AR (OR, 5.92; 95% CI, 2.00-17.55; = 0.001) was associated with AWE. In the high-AR group of 45 aneurysms with AWE, the aneurysm sac exhibited lower blood flow velocity, lower wall shear stress, a larger proportion of low-flow regions and higher wall enhancement values. In total, 15 silicone models were analyzed, divided into three subgroups based on neck width (4 mm, 6 mm, and 8 mm). Each subgroup contained aneurysms with five different ARs: 1.0, 1.25, 1.5, 1.75, and 2.0. In silicone models, contrast enhancement (CE) was mainly located beneath the dome of the aneurysm wall. With the same inlet velocity, CE gradually increased as the AR increased. Similarly, at the same AR, CE increased as the inlet velocity decreased. CFD demonstrated a moderate positive correlation between the near-wall enhancement index and the ratio of the low-velocity area (r = 0.6672, < 0.001). The AR is associated with the AWE of MCA bifurcation aneurysms. A high AR may promote wall enhancement by causing near-wall slow flow.
大脑中动脉（MCA）分叉处动脉瘤在血管壁磁共振成像（VW-MRI）上的瘤壁强化（AWE）机制尚不清楚。我们旨在探讨与MCA分叉处动脉瘤AWE相关的形态学血流动力学机制。纳入接受VW-MRI检查的未破裂MCA分叉处动脉瘤患者。进行逻辑回归分析以确定AWE的危险因素。基于回顾性分析结果，设计了具有特定纵横比（AR）的分叉动脉瘤硅胶模型，并在不同入口速度下进行VW-MRI检查。对硅胶模型和患者的动脉瘤均进行了计算流体动力学（CFD）分析。95例患者（平均年龄60岁；男性34例）共104个动脉瘤纳入基线分析和形态学分析。逻辑回归分析表明，AR（比值比，5.92；95%置信区间，2.00 - 17.55；P = 0.001）与AWE相关。在45个存在AWE的高AR组动脉瘤中，瘤囊表现出较低的血流速度、较低的壁面切应力、较大比例的低血流区域和较高的瘤壁强化值。共分析了15个硅胶模型，根据颈部宽度分为三个亚组（4毫米、6毫米和8毫米）。每个亚组包含具有五种不同AR的动脉瘤：1.0、1.25、1.5、1.75和2.0。在硅胶模型中，对比增强（CE）主要位于动脉瘤壁穹顶下方。在相同入口速度下，CE随AR增加而逐渐增加。同样，在相同AR下，CE随入口速度降低而增加。CFD显示近壁强化指数与低速区域比例之间存在中度正相关（r = 0.6672，P < 0.001）。AR与MCA分叉处动脉瘤的AWE相关。高AR可能通过导致近壁血流缓慢来促进瘤壁强化。
