多普勒超声联合指标在肾动脉狭窄诊断中的应用

目的探讨多普勒超声指标联合应用在肾动脉狭窄(RAS)诊断中的应用。方法对234例RAS患者采用多普勒超声测量用于诊断RAS的相关超声指标,包括肾动脉峰值流速(RPSV)、肾动脉与腹主动脉收缩期峰值流速比值(RAR)、肾动脉与叶间动脉峰值流速比值(RIR)以及肾内叶间动脉收缩早期加速时间(AT)、收缩早期加速度(AC)、阻力指数(RI),随后行血管造影检查。肾动脉造影显示肾动脉内径减少≥60%患者确定为RAS。使用ROC曲线计算每一项指标最佳阈值的诊断敏感性、特异性和准确性,同时计算两项和3项联合指标的诊断效率。结果在血管造影和多普勒超声显示的422条肾动脉中,血管造影显示185条RAS(肾动脉内径减少60%～99%)和19条闭塞。采用RPSV170cm/s或AT≥0.07s作为联合诊断标准,获得敏感性95.1%,特异性87.2%,准确性90.8%,较任何单一指标的诊断效果均有所提高。而采用RPSV170cm/s、RIR5.6和AT≥0.07s作为联合诊断指标,虽诊断敏感性提高了1.7%,但特异性下降了3.7%。结论对于诊断肾动脉内径减少≥60%的RAS,RPSV和RIR是较好的单一多普勒指标。RPSV和AT联合应用可获得最佳的诊断准确率,具有一定的临床应用价值。

Diagnostic value of velocity combination parameters in detection of renal artery stenosis

Objective To evaluate the diagnostic value of the combination of Doppler parameters for the detection of renal artery stenosis （RAS） （diameter reduction 〉160% ） . Methods A study group included 234 patients whose renal arteries were detected by color Doppler flow imaging and were referred to renal arteri- ography afterwards. Firstly, RPSV （ the renal peak systolic velocity）, RAR （ a ratio of the PSV in the renal ar- tery to that in the aorta）, and RIR （a ratio of the PSV in the renal artery to that in the interlobar artery） were measured as direct parameters, then AT （acceleration time）, AC （acceleration） and RI （resistant index） were recorded as indirect parameters. Arteries were considered stenosed on renal arteriography if a diameter re- duction of/〉 60% was observed. Statistical analysis of the best parameters for predicting a RAS was performed with ROC （receive operating characteristic） curves. The sensitivity, specificity, negative and positive predictive values and accuracy at various cutoff values were calculated. Results In the 422 renal arteries demon- strated by renal arteriography, there were 185 stenoses and 19 occlusions. ROC analysis showed that the com- bination of RPSV and AT was the first choice. In case the cutoff values of RPSV 〉 170 cm/s and ATe〉0.07 s for the detection of RAS were used, the sensitivity was 95.1% ,the state of specificity was 87.2% ,and accuracy was 90.8%, respectively. By using the combination of RIR 〉5.6, RPSV 〉 170 cm/s and ATe〉0.07 s, the rate of sensitivity increased by 1.7%, while the rate of specificity decreased by 3.7% compared with the combination of RPSV 〉 170 cm/s and AT I〉0.07 s. Conclusions The RPSV and RIR are the best two parameters to detect RAS（ diameter reduction of/〉60% ）among the six single Doppler parameters, and the combination of RPSV 〉 170 cm/s and ATe〉0.07 s provided the best diagnostic efficiency.