Supplementary Material for: Tortuosity and Proximal-Specific Hemodynamics Associated with Plaque Location in the Carotid Bulb Stenosis

Background: The occurrence of carotid bulb plaque is a complex process. We aimed to investigate plaque characteristics and geometric and hemodynamic parameters among patients with body and apical plaques of the carotid bulb and to identify the mechanism of bulb plaque formation and location. Methods: Consecutive patients with single carotid bulb stenosis (50–99%) were enrolled retrospectively. Patients were divided into body and apical plaque groups based on plaque location. Plaque location and characteristics were identified and measured on high-resolution vessel wall magnetic resonance imaging. Geometric parameters were derived from time-of-flight magnetic resonance imaging. Computational fluid dynamics simulations were performed to quantify wall shear stress (WSS). Results: Seventy patients were recruited (41 body plaques and 29 apical plaques). WSSplaque values were lower than WSSnon-plaque values for all plaques (median [IQR], 12.59 [9.83-22.14] vs. 17.27 [11.63-27.63] Pa, p = 0.001). In a multivariate binary logistic regression, the tortuosity of the stenosed region, the magnitudes of the mean relative residence time, and the minimum transverse WSS in the proximal part of the lesion were the key factors independently associated with plaque location (p = 0.022, 0.013, and 0.012, respectively). Conclusions: Plaque formation was associated with local flow pattern, and the tortuosity and proximal-specific hemodynamics were significantly associated with plaque location in the carotid bulb.【背景】颈动脉球斑块的发生是一个复杂的病理过程。本研究旨在探讨颈动脉球体部与尖部斑块患者的斑块特征、几何参数及血流动力学参数，明确颈动脉球斑块的形成机制与好发部位。【方法】本研究回顾性纳入连续就诊的单侧颈动脉球狭窄（50%~99%）患者，根据斑块位置分为体部斑块组与尖部斑块组。采用高分辨血管壁磁共振成像识别并测量斑块位置与特征，通过飞行时间磁共振成像获取几何参数，并通过计算流体动力学模拟量化壁面切应力（wall shear stress, WSS）。【结果】共纳入70例患者，其中体部斑块41例，尖部斑块29例。所有斑块的斑块区域WSS均低于非斑块区域（中位数[四分位间距]：12.59[9.83~22.14] Pa 与 17.27[11.63~27.63] Pa，p=0.001）。多因素二元logistic回归分析显示，狭窄区域迂曲度、平均相对滞留时间（relative residence time, RRT）以及病变近端的最小横向WSS是与斑块位置独立相关的关键因素（对应p值分别为0.022、0.013与0.012）。【结论】斑块形成与局部血流模式密切相关，颈动脉球的斑块好发部位与狭窄区域迂曲度及病变近端特异性血流动力学特征显著相关。