动脉粥样硬化性与非动脉粥样硬化性肾动脉狭窄的彩色多普勒超声表现差异

目的 评价5项有代表性且具有诊断价值的超声指标在肾动脉狭窄(RAS)类型之间的差异.方法 221例RAS患者首先进行彩色多普勒超声检查.测量5项多普勒超声指标.包括肾动脉峰值流速(RPSV)、肾动脉-腹主动脉峰值流速比值(RAR)、肾动脉-叶间动脉峰值流速比值(RIR)、加速时间(AT)和阻力指数(RI),随后进行肾动脉造影检查.造影显示管腔内径减少≥50%者视为RAS.采用卡方检验分析不同病因组间的统计学差异,单因素方差分析或t检验比较组间平均值差异.选择敏感性与特异性之和最大值时的阈值为最佳诊断阈值.结果 在动脉造影所显示的442条肾动脉(包括主肾动脉和副肾动脉)中,214条正常或狭窄程度＜50%,204条存在狭窄(内径减少50%～99%),其余24条闭塞.多普勒超声检查成功率为91.4%(404/442).动脉粥样硬化性与非动脉粥样硬化性RAS相比,RIR、RAR及RI测值差异具有统计学意义(P＜0.05),而RPSV、AT测值差异无统计学意义.两组间RAR、RIR和RI的最佳诊断阈值相差较大(2.5对1.9,5.1对6.5,0.57对0.50),但RPSV和AT的最佳诊断阈值相差较小或相等(170 cm/s对200 cm/s,51 ms对51 ms).结论 对于内径减少≥50%RAS,最好针对动脉粥样硬化性与非动脉粥样硬化性RAS分别建立RAR、RIR和RI指标的诊断标准,而RPSV和AT应建立统一的诊断标准.RIR是诊断RAS尤其动脉粥样硬化性和纤维肌性发育不良性RAS的良好指标.

Differences in the findings of color Doppler sonography between atherosclerotic and non-atherosclerotic renal artery stenosis

Objective To evaluate the differences among five representative and useful Doppler parameters in the diagnosis of the three common types of renal artery stenosis (RAS). Methods Five Doppler parameters including renal peak systolic velocity (RPSV), renal-aortic ratio (RAR), renal-interlobar ratio (RIR),acceleration time (AT),and resistant index (RI) were measured in 221 patients before renal arteriography. Differences between the groups of patients with various clinical causes of RAS were analyzed by Chi-Squared test. One-way ANOVA or t test were used to compare the means between different groups.The optimal cutoff value was determined with the maximum sum of sensitivity and specificity. Results Of the 442 renal arteries (main and accessory renal arteries) demonstrated at arteriography,214 were normal or stenosed less than 50 %, 204 stenoses 50% - 99 %, and 24 occlusions. RIR, RAR and RI were significantly different between the atherosclerotic and non-atherosclerotic RAS groups (P ＜0.05), while RPSV and AT were not. The optimal cutoff values of RAR,RIR and RI for detecting RAS between the atherosclerotic and non-atherosclerotic groups were much different (2.5 versus 1.9, 5. 1 versus 6.5, 0.57 versus 0.50,respectively) ,but those of RPSV and AT were similar or the same (170 cm/s versus 200 cm/s,51 ms versus 51 ms,respectively). Conclusions In the case of RAS (diameter reduction≥50%),it is advised to establish separate cutoff values of RAR, RIR and RI according to atherosclerotic and non-atherosclerotic RAS, but the same cutoff value of RPSV and AT can be applied. RIR is a good Doppler parameter in the diagnosis of RAS,especially atherosclerotic and fibromuscular dysplasia RAS.