Volume flow measurement in hemodialysis shunts using time-domain correlation

Volume flow was measured in 58 hemodialysis shunts (32 grafts and 26 radial fistulas) using the color velocity imaging-quantification method. This met hod is based on time-domain correlation for velocity calculation and integr ation of time-varying velocity profiles generated by M-mode sampling. Measu rements were made in the brachial artery to estimate radial fistula flow or directly in the grafts. Intraoperator reproducibility was 14.9% for fistul as and 11.6% for grafts. Flow rate was significantly lower in abnormal shun ts associated with a functional disorder or a morphologic complication (808 ml/min +/- 484) than in shunts associated with no abnormalities (1401 ml/m in +/- 562). Receiver operating characteristic curves showed that a flow ra te of 900 ml/min for fistulas and 1300 ml/min for grafts provided 81% and 7 9% sensitivity and 79% and 67% specificity, respectively. A functional diso rder or a morphologic complication was associated with all fistulas and gra fts in which flow rates were lower than 500 ml/min and 800 ml/min, respecti vely.