LAUSR

BACKGROUND Conventional ultrasound (US), which include grey-scale US and doppler US, is the first-line imaging modality for the evaluation of renal allograft; however, conventional US indicators have limitations. OBJECTIVE To explore the application value of shear-wave elastography (SWE) combined with monochrome superb microvascular imaging (mSMI) in renal allograft chronic rejection (CR). METHODS From November 2021 to February 2022 in the Lanzhou University Second Hospital, the US features of 54 patients with renal allograft were retrospectively analyzed. Patients were categorized into two groups: stable group(n = 44) and CR group(n = 10), with clinical diagnosis as reference standard. The vascular index (VI) on mSMI and parenchymal stiffness were measured in the middle cortex of all renal allografts and receiver operating characteristic (ROC) curves were drawn to evaluate the feasibility of differentiation. Statistically significant US features and biochemical indicators such as creatinine were scored, and the results of the scores were analyzed by ROC curve. RESULTS The VI on mSMI of the stable group (49.5±2.0) was significantly greater than that of the CR group (33.8±5.9) (P = 0.028). There was a statistically significant difference in parenchymal stiffness between stable group (16.2kPa±1.2) and CR group (33.9kPa±6.6) (P = 0.027). The sensitivity was 90% and specificity was 81.8% of the scores in the differentiation of stable group from CR group (cut-off value, 2; P = 0.000). CONCLUSION SWE combined with mSMI may help differentiate stable renal allograft from renal allograft CR and have the potential application value in the diagnosis of renal allograft CR.