Clinical value of color Doppler ultrasonography in evaluating the degree of atherosclerotic renal artery stenosis in the elderly by ROC curve analysis

Objective To evaluate the clinical value of color Doppler ultrasonography (CDFI) in evaluating the degree of atherosclerotic renal artery stenosis (ARAS) in the elderly by using ROC curve analysis. Methods From March 2015 to September 2018, 117 patients with ARAS admitted to Anji Branch of the First Affiliated Hospital of Medical College of Zhejiang University were selected.All patients underwent color Doppler ultrasonography and renal artery angiography.Renal artery angiography was used as the gold standard.The diagnostic value of color Doppler ultrasonography for ARAS was analyzed.The changes of color Doppler ultrasonography indicators of renal artery in different degrees of stenosis were compared.The ROC curve was used to analyze the value of color Doppler ultrasound in evaluating the degree of atherosclerotic renal artery stenosis in the elderly. Results Using renal arteriography as the gold standard, the sensitivity of color ultrasonography for ARAS was 82.17% (129/157), and the specificity of diagnosis was 80.52% (62/77). The PSV [(227.59±34.28)cm/s] and EDV [(57.39±6.48)cm/s] in the severe stenosis group were higher than those in the moderate stenosis group [(183.84±41.05) cm/s and (50.29±5.22)cm/s] (t=6.269, 6.506, all P<0.05) and the mild stenosis group [(128.47±52.35)cm/s and (37.52±7.15)cm/s] (t=10.517, 12.813, all P<0.05) and the non-stenosis group [(86.49±28.94)cm/s and (26.48±5.02)cm/s] (t=18.598, 21.971, all P<0.05). The RI in the severe stenosis group[(0.41±0.07)] was lower than that in the moderate stenosis group [(0.47±0.06)] (t=4.966, P<0.05) and the mild stenosis group [(0.52±0.07)] (t=8.496, P<0.05) and the no stenosis group [(0.70±0.11)] (t=17.101, P<0.05). The ROC curve was used to analyze the diagnostic value of color ultrasound parameters for moderate and severe stenosis.The area under the diagnostic curve of PSV, EDV and RI for moderate and severe stenosis was 0.869, 0.932 and 0.937, respectively. Conclusion CDFI plays an important role in the early diagnosis and clinical screening of elderly patients with ARAS.It is helpful to judge the degree of renal artery stenosis and evaluate the condition of the patients.It is non-invasive, simple and inexpensive, and worthy of clinical application. Key words: Ultrasonography, doppler, color; ROC curve; Atherosclerotic renal artery stenosis; Blood flow velocity; End-diastolic flow velocity; Peak velocity ratio; Resistance index; Aged