Alteration in shear wave elastography is associated with acute kidney injury: A prospective observational pilot study

Kidney stiffness could change during kidney disease. We hypothesize that acute kidney injury (AKI) would increase renal stiffness. Therefore, evaluating kidney Young's modulus (YM, a measure of tissue stiffness) using shear wave elastography (SWE) might help to diagnose AKI.This research was divided into two studies. Study A: Male C57BL/6 mice were used to observe kidney YM changes induced by sepsis-associated AKI, which was established by caecal ligation and puncture (CLP). Study B included 54 consecutive critically ill patients with or without AKI. Changes in renal YM were observed.Study A: CLP mice showed a significantly higher kidney YM compared to the sham group. The YM gradually increased from CLP 0-hour to CLP 24 hours. And, presented a fair relationship with the renal tubular injury score (R2 = 0.71) and serum creatinine (R2 = 0.73). Study B: YM was easily accessible and the intraclass correlation coefficient ranged from 0.62 to 0.84. Kidney YM was higher in AKI patients and gradually increased from non-AKI to AKI III patients. Furthermore, the YM in the upper, middle and lower poles renal cortex presented a fair relationship with kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin (R2 ranging from 0.4 to 0.58). And the area under curves of the above five indicators for the diagnosis of AKI were 0.7, 0.73, 0.70, 0.74, and 0.79, respectively.SWE-derived estimates of renal stiffness are higher in AKI patients and sepsis-associated AKI mice. However, it has no advantage over NGAL and KIM-1.Trial registration: Chinese Clinical Trial Registry No: ChiCTR2200061725. Retrospectively registered on 1 July 2022, https://www.chictr.org.cn/showproj.aspx?proj=169359.