Evaluation of Renal Microperfusion in Diabetic Patients With Kidney Injury by Contrast‐Enhanced Ultrasound

Objectives To conduct a quantitative analysis of renal microvascular perfusion in diabetic patients with kidney injury using contrast‐enhanced ultrasound (CEUS). Methods A total of 172 patients with type 2 diabetes mellitus and kidney injury were recruited from May 2017 to November 2019. After collection of clinical characteristics, a CEUS examination was performed after injection of the contrast agent SonoVue (Bracco SpA, Milan, Italy). Time‐intensity curves and renal perfusion parameters were analyzed. Ultrasound‐guided renal biopsy was performed. The patients were divided into a diabetic nephropathy (DN) group and a nondiabetic renal disease (NDRD) group according to renal pathologic results. The discrimination of perfusion parameters between the groups was analyzed statistically with SPSS version 19.0 software (IBM Corporation, Armonk, NY). Receiver operating characteristic curves were used to illustrate the diagnostic performance of indicators. Results Ninety‐eight patients, including 45 with DN (29 male; mean age ± SD, 57.76 ± 10.47 years) and 53 with NDRD (40 male; mean age, 48.7 ± 13.88 years) were included in this study. The peak enhancement (PE), wash‐in the area under the curve (AUC), wash‐in rate, wash‐in perfusion index, wash‐out AUC, wash‐in and wash‐out AUC, and wash‐out rate were significantly different between the groups ( P < .05). There were no differences in time‐related parameters between the DN and NDRD groups ( P > .05). The receiver operating characteristic curve analysis showed that the AUC for PE was 0.727, and PE lower than 7712.426 had diagnostic potential, with sensitivity of 81% and specificity of 40% in discriminating between NDRD and DN. Conclusions The quantification of CEUS parameters can discriminate DN in diabetic patients with kidney injury. The PE and AUC may be feasible parameters.