Non-invasive determination of the severity of parenchymal injury in acute kidney injury (AKI) remains challenging. Edema is an early pathological process following injury, which may correlate with changes in kidney volume. The goal of this study was to test the hypothesis that 'increases in kidney volume, measured in vivo using ultrasound correlate with the degree of renal parenchymal injury'. Ischemia reperfusion (IR) of varying length was utilized to produce graded tissue injury. We first determined 1) whether regional kidney volume in rats varied with the severity (0, 15, 30, 45 minutes) of warm bilateral IR and 2) whether this correlated with tubular injury score. We then determined whether these changes could be measured in vivo using 3D ultrasound. Finally, we evaluated cumulative changes in kidney volume up to 14 days post-IR in rats to determine whether changes in renal volume were predictive of latent tubular injury following recovery of filtration. Studies concluded that non-invasive ultrasound measurements of change in kidney volume over 2 weeks are predictive of tubular injury following IR even in animals in which plasma creatinine was not elevated. We conclude that ultrasound measurements of volume are a sensitive, non-invasive marker of tissue injury in rats and that the use of 3D-ultrasound measurements may provide useful information regarding the timing, severity and recovery from renal tissue injury in experimental studies.

中文翻译：

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肾脏体积变化的超声测量是肾实质损伤严重程度的敏感指标。

急性肾损伤 (AKI) 实质损伤严重程度的非侵入性测定仍然具有挑战性。水肿是损伤后的早期病理过程，可能与肾脏体积的变化有关。本研究的目的是检验“使用超声在体内测量的肾脏体积增加与肾实质损伤程度相关”的假设。不同长度的缺血再灌注 (IR) 用于产生分级组织损伤。我们首先确定 1) 大鼠的局部肾脏体积是否随双侧热 IR 的严重程度（0、15、30、45 分钟）而变化，以及 2）这是否与肾小管损伤评分相关。然后我们确定是否可以使用 3D 超声在体内测量这些变化。最后，我们评估了大鼠 IR 后长达 14 天肾脏体积的累积变化，以确定肾脏体积的变化是否预示着滤过恢复后的潜在肾小管损伤。研究得出结论，即使在血浆肌酐没有升高的动物中，2 周内肾脏体积变化的无创超声测量也可以预测 IR 后肾小管损伤。我们得出结论，体积的超声测量是大鼠组织损伤的敏感、非侵入性标志物，并且使用 3D 超声测量可以提供有关实验研究中肾组织损伤的时间、严重程度和恢复的有用信息。研究得出结论，即使在血浆肌酐没有升高的动物中，2 周内肾脏体积变化的无创超声测量也可以预测 IR 后肾小管损伤。我们得出结论，体积的超声测量是大鼠组织损伤的敏感、非侵入性标志物，并且使用 3D 超声测量可以提供有关实验研究中肾组织损伤的时间、严重程度和恢复的有用信息。研究得出结论，即使在血浆肌酐没有升高的动物中，2 周内肾脏体积变化的无创超声测量也可以预测 IR 后肾小管损伤。我们得出结论，体积的超声测量是大鼠组织损伤的敏感、非侵入性标志物，并且使用 3D 超声测量可以提供有关实验研究中肾组织损伤的时间、严重程度和恢复的有用信息。