Department of Ultrasound, Zhongshan Hospital, Fudan University, Shanghai, China.
Clin Hemorheol Microcirc. 2020;74(4):453-462. doi: 10.3233/CH-190719.
To evaluate the feasibility of vector flow imaging technique (V Flow) in measurement of wall shear stress (WSS) of common carotid arteries (CCA) in healthy adults and to provide the normal WSS values assessed by V Flow.
METHODS & MATERIALS: This prospective study was approved by the Ethics Committee of our University. Eighty healthy adult volunteers were included (mean age 43.3 y, 47 females, 33 males). The volunteers were classified into three groups according to their age: group I (age 20 - 39 y), group II (age 40 - 59 y) and group III (age 60 - 80 y). Mindray Resona 8 ultrasound machine and a linear array transducer (3-9 MHz) was used, equipped with the updated V Flow function. Common carotid arteries of both sides were evaluated in three segments (initial segment, middle segment and near bifurcation segment). The WSS values of CCA were measured by two independent radiologists. The intraclass correlation coefficient (ICC) of observer reliability in WSS measurement was calculated. Inter-observer reproducibility was also evaluated with the 95% Bland-Altman limits of agreement (LOA).
V Flow measurements were performed successfully in 79 volunteers (98.8 %, 79/80). The mean value of WSS in right CCA was (0.66±0.24) Pa, in left CCA was (0.66±0.18) Pa (P > 0.05). Mean WSS value had a moderately negative correlation with age group (P < 0.05). The mean WSS value of group I(mean±SD, 0.75±0.25 Pa) is larger than group II (mean±SD, 0.62±0.13 Pa) and group III (mean±SD, 0.49±0.11 Pa) (P < 0.05). The ICC of observer reliability of group I, II and III was 0.96 (95% confidence interval (95% CI) 0.92-0.98), 0.94 (95% CI 0.88-0.97), 0.93 (95% CI 0.76-0.98) respectively. The Bland-Altman plots showed that the 95% LOA were -0.17-0.12 (Pa) for group I, -0.09-0.13 (Pa) for group II and -0.08-0.10 (Pa) for group III.
V Flow measurement is a simple, rapid and feasible imaging method for the WSS assessment of CCA in healthy volunteers, which will probably be an important tool for assessing CCA function.
评估向量流成像技术（VFlow）测量健康成年人颈总动脉（CCA）壁切应力（WSS）的可行性，并提供 VFlow 评估的正常 WSS 值。
本前瞻性研究经大学伦理委员会批准。纳入 80 名健康成年志愿者（平均年龄 43.3 岁，47 名女性，33 名男性）。根据年龄将志愿者分为三组：I 组（20-39 岁）、II 组（40-59 岁）和 III 组（60-80 岁）。使用 Mindray Resona 8 超声仪和线阵探头（3-9MHz），配备最新的 VFlow 功能。评估双侧 CCA 的三个节段（起始段、中段和近分叉段）。由两位独立的放射科医生测量 CCA 的 WSS 值。计算观察者测量 WSS 时的组内相关系数（ICC）。采用 95% Bland-Altman 一致性界限（LOA）评估观察者间可重复性。
79 名志愿者（98.8%，79/80）成功进行了 VFlow 测量。右侧 CCA 的平均 WSS 值为（0.66±0.24）Pa，左侧 CCA 的平均 WSS 值为（0.66±0.18）Pa（P＞0.05）。平均 WSS 值与年龄组呈中度负相关（P＜0.05）。I 组（均数±标准差，0.75±0.25 Pa）的平均 WSS 值大于 II 组（均数±标准差，0.62±0.13 Pa）和 III 组（均数±标准差，0.49±0.11 Pa）（P＜0.05）。I 组、II 组和 III 组观察者可靠性的 ICC 分别为 0.96（95%置信区间（95%CI）0.92-0.98）、0.94（95%CI 0.88-0.97）和 0.93（95%CI 0.76-0.98）。Bland-Altman 图显示，I 组的 95%LOA 为-0.17-0.12（Pa），II 组为-0.09-0.13（Pa），III 组为-0.08-0.10（Pa）。
VFlow 测量是一种简单、快速、可行的 CCA 壁切应力评估成像方法，可能成为评估 CCA 功能的重要工具。
