目的 应用彩色多普勒超声探讨肱动脉血流量(blood flow volume,Qa)/阻力指数(resistance index,RI)评价动静脉内瘘狭窄的价值。 方法 回顾性分析2020年1月～2021年9月在大连理工大学附属大连市中心医院肾内科透析的患者，根据超声测量静脉内径，＜2mm为狭窄组(n=75)，≥2mm为正常组(n=109)，记录超声测量指标Qa、RI、Qx(肱动脉血流量/阻力指数，Qx=Qa/RI)及性别、年龄、体质量指数(body mass index,BMI)、是否患有糖尿病、是否吸烟等。 结果 狭窄组和正常组在性别(t=1.400，P=0.270)、BMI(χ2=9.105,P=0.448)、是否吸烟(t=0.043P，=0.834)的差异没有统计学意义。正常组和狭窄组比较在糖尿病(t=0.059，P＜0.001)、Qa(χ2=42.868，P＜0.001)、RI(χ2=42.823，P＜0.001)、Qx(χ2=40.919，P＜0.001)差异有统计学意义。Logistic回归分析结果显示Qx是诊断内瘘狭窄的有效指标(OR=0.997，95% CI：0.995～0.998，P＜0.001)。ROC曲线结果显示：Qx与Qa没有显著差异，Qx与RI有显著差异(AUC Qa-Qx，P=0.071，AUC Qx-RI，P＜0.001)。 结论 Qx是评估内瘘狭窄的有效指标，结合Qa和RI可以有效诊断内瘘狭窄。

Objective  The resistance index (RI) and blood flow volume (Qa) are two important Doppler ultrasound parameters to identify the stenosis in arteriovenous fistula (AVF). In this study, we aimed to evaluate the diagnostic capability of Qa/RI (Qx) for the early identification of AVF stenosis.  Methods  A total of 184 hemodialysis patients treated in Dalian Municipal Central Hospital were enrolled in this study. Patients were categorized by ultrasound measurement of the vein diameter as stenosis group (diameter <2mm, n=75) or non-stenosis group (diameter ≥2mm, n=109). Clinical data, Qa, RI, and Qx were recorded.  Results  The stenosis and non-stenosis groups were homogeneous in number, sex, BMI and smoking habit. Diabetes (t=0.059, P<0.001), Qa (c2=42.868, P<0.001), RI (c2=42.823, P<0.001) and Qx        (c2=40.919, P<0.001) were different between stenosis group and non-stenosis group. Logistic regression showed that Qx was a valid index for evaluating AVF stenosis (OR=0.997, 95% CI=0.995~0.998, P＜0.001). ROC revealed that Qx was better than RI (AUC Qx-RI, P＜0.001) but Qx and Qa had similar capability (AUC Qa-Qx, P=0.071) for the identification of AVF stenosis.  Conclusions  In hemodialysis patients, Qx was more reliable than RI but Qx and Qa had similar capability for the early identification of AVF stenosis.