Abstract: 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.

Key words: Color Doppler ultrasound, Blood flow, Resistance index, Arteriovenous fistula stenosis