To explore the performance of ultrasound elastography in staging diabetic kidney disease: a systematic review and meta-analysis.

To assess the diagnostic performance of different quantitative ultrasound elastography (USE) parameters in differentiating five stages of diabetic kidney disease (DKD) from each other as well as from healthy participants and type 2 diabetic patients without nephropathy. The protocol was pre-registered at https://osf.io/dfu8b/ . Using PubMed, Web of Science, Embase, and Cochrane Library, we found studies up to October 10, 2023. Risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). The USE parameter of cortical stiffness was compared in an inter-stage manner based on mean differences, standardized mean differences, and ratios of means. In addition, cortical stiffness was evaluated for its diagnostic accuracy in staging DKD. Sensitivity and publication bias analyses were also conducted. Certainty of evidence was assessed using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE). Eighteen studies were included with 2814 participants. The mean stiffness value consistently increased with the progression of the disease. Differentiation of five stages of DKD from two non-DKD groups, respectively, showed sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under curve of 79%, 83%, 4.70, 0.25, 18.68, and 0.88. These values for differentiation of stages 3 to 5 of DKD from the other four milder groups were 80%, 79%, 3.85, 0.25, 15.53, and 0.87, respectively. USE shows promise as a noninvasive, simple, and quantitative diagnostic tool for staging DKD, especially in its early stages. With standardized protocols, its application could benefit patient management by enhancing the accuracy of DKD staging.