RÉSUMÉ
Objective:To explore the feasibility of contrast-enhanced ultrasound in assessing the degree of transplant renal artery stenosis(TRAS)and evaluate its diagnostic efficacy of severe TRAS.Methods:From February 2013 to February 2022, clinical and follow-up data are retrospectively reviewed for 23 TRAS recipients.A definite diagnosis is made by magnetic resonance angiography (MRA, 2 cases)or digital subtraction angiography(DSA, 21 cases). They are assigned into two groups of mild-moderate stenosis(5 cases)and severe stenosis(18 cases)according to the diameter reduction rate of transplanted renal artery detected by DSA/MRA.Another 32 recipients of stable renal function are selected as controls.All contrast-enhanced ultrasonic images are quantitatively processed with SonoLiver.The following quantitative parameters are obtained, including rising time of interlobular artery(RTi), rising time of cortex(RTc), rising time of medulla(RTm), time to peak of interlobular artery(TTPi), time to peak of cortex(TTPc)and time to peak of medulla(TTPm). The differences of contrast-enhanced ultrasonic quantitative parameters are compared among three groups.And their diagnostic efficacies are calculated in the diagnosis of severe TRAS.Results:As compared with those in normal group, RTi, RTc, TTPi and TTPc are significantly longer in mild-moderate stenosis group(all P<0.05); Meanwhile, RTi, RTc, RTm, TTPi, TTPc and TTPm are significantly longer in severe stenosis group than those in normal group(all P<0.05); Comparing mild-moderate stenosis and severe stenosis groups, only RTm is significantly different between two groups( P<0.05). Among all the above parameters, RTc has the highest diagnostic efficacy in the diagnosis of severe TRAS(AUC=0.848)with a sensitivity of 72.22%, a specificity of 86.49% and an accuracy of 81.82%. Conclusions:The quantitative parameters of contrast-enhanced ultrasound offer aid in assessing the degree of TRAS.And RTc is the most valuable in the diagnosis of severe TRAS.