Objective To investigate the predictive value of quantitative parameters of contrast-enhanced ultrasound (CEUS) in evaluating kidneys from donation after brain death (DBD) for the occurrence of delayed graft function (DGF) in recipients.

Methods The clinical data of 134 DBD donors and 202 corresponding kidneys and recipients were retrospective analyzed. The recipients were divided into DGF group (n=39) and non-DGF group (n=163) according to the renal function after kidney transplantation. Conventional ultrasound, CEUS parameters, and clinical data were compared between the two groups. Receiver operating characteristic (ROC) curves were used to determine the optimal cut-off values for predicting DGF using CEUS parameters, clinical parameters, and their combination, based on the highest Youden index. The predictive ability of different parameters for DGF was evaluated.

Results There were statistically significant differences in cortical peak intensity (PIc), medullary peak intensity (PIm), donor albumin (ALB), serum creatinine (Scr) after admission, and the Na⁺ concentration of recipients between the two groups (all P<0.05). The area under the curve (AUC) for predicting DGF using the combination of CEUS parameters PIc and PIm was 0.711, with an optimal cut-off value of 0.193 and a Youden index of 0.382. The AUC for predicting DGF using the combination of CEUS parameters PIc, PIm and clinical parameters was 0.808, with an optimal cut-off value of 0.191 and a Youden index of 0.517. The sensitivity and specificity were 0.769 and 0.613 for the former, and 0.769 and 0.748 for the latter, respectively. The AUC for predicting DGF using CEUS parameters PIc and PIm combined with clinical parameters was significantly higher than that using CEUS parameters PIc and PIm (P<0.05).

Conclusions The CEUS quantitative parameters PIc and PIm have good predictive value in assessing kidneys from DBD donors for DGF in recipients, and the diagnostic efficacy is better when combined with clinical parameters.