Contrast-enhanced ultrasound with SonoVue could accurately assess the renal microvascular perfusion in diabetic kidney damage

Abstract

The aim of this study was to investigate the clinical significance of real-time gray-scale contrast-enhanced ultrasound (CEUS) through evaluating renal microvascular perfusion in diabetic kidney damage. Diabetic patients (aged: 62.5±7.2, n=33) were divided into Group A with chronic kidney disease (CKD) Stages I and II (n=19) and Group B (n=14) with CKD Stages IV and V. Twenty-one healthy adults were selected as control group. The real-time and dynamic imaging from renal cortex was performed using contrast-enhanced ultrasound with SonoVue. The outage time-intensity curves (TICs) with >85% goodness-of-fit index were chosen for the analysis of basic intensity, intensity increment (A1), arriving time (AT), time to peak (TTP), mean transit time, peak intensity (PI) and total area under the curve (AUC). (i) After intravenous injection of a contrast agent, the renal artery, cortex, pyramid and renal vein were clearly displayed in sequence. (ii) TIC of renal cortical Perfusion in all groups showed an asymmetrical single-peak curve, which has an obvious ascending slope, peak and descending slope. The ascending slope was steep, whereas the descending slope was flat. However, the ascending slope in Group A and B was flatter than that in the control group. (iii) Compared to the control group, AT and TTP were all markedly prolonged but A1 and PI were significantly decreased in Group A and B (P<0.05). In Group A, the AUC had a trend of increase; however, the area under the ascending slope (AUC1), area under the descending slope (AUC2) and AUC were all decreased in Group B (P<0.05). (iv) AUC positively correlated with glomerular filtration rate (GFR) (r=0.472, P=0.01), but TTP did not correlate well with GFR (r=0.262, P=0.177). CEUS could accurately assess renal microvascular perfusion in a real-time and dynamic manner. PI, TTP and AUC could be used for the diagnosis of the renal microvascular damage in early and late stage diabetic patients. CEUS is a safe, noninvasive and simple technique to detect the severity of kidney microvascular perfusion deficits.