Interobserver reproducibility of contrast-enhanced ultrasound in diabetic nephropathy

Abstract

Objective: To investigate the interobserver reproducibility of contrast-enhanced ultrasound (CEUS) in patients with diabetic nephropathy. Methods: A total of 40 patients with diabetic nephropathy were enrolled in this retrospective study. We measured peak intensity (PEAK), time-to-peak (TP), area under the curve (AUC) and mean transit time (MTT) of renal CEUS in each patient. Each parameter was performed by two independent observers. The interobserver reproducibility was assessed using intraclass correlation coefficients (ICCs) with 95% confidence intervals (CIs) and Bland–Altman plots by mean difference with 95% limits of agreement (LOAs). Results: The parameters of the left and right kidneys showed moderate or good reliability. The best was the left kidney AUC parameters (ICC,0.945),with a 95% CI of 0.896–0.971.The Bland–Altman plots showed that the mean differences between the right renal parameters (PEAK, TP, AUC and MTT) obtained between the observers 1 and 2 were −6.63%,2.54%,−11.30%,−2.22%, and the 95% LOAs are −30.78 to 17.52%, −30.15 to 35.23%, −43.95 to 21.35%, −44.50 to 40.06%. While the left ones were −2.89%, 0.32%, −8.26%, 1.25% , and the 95% LOAs were −38.50 to 32.72%, −31.98 to 32.62%, −57.89 to 41.37%, −37.21 to 39.71%, respectively. Conclusion: Quantitative CEUS can show good interobserver reproducibility, which is better for the right kidney. It seems necessary to establish standardized techniques for obtaining contrast-enhanced quantitative analysis of renal blood perfusion. Advances in knowledge: Quantitative assessment of renal perfusion by CEUS in patients with diabetic nephropathy provides diagnostic information. Furthermore, renal perfusion assessment in patients with diabetic nephropathy using CEUS has good reproducibility.