Background Acute kidney injury affects nearly 30% of preterm neonates in the intensive care unit. We aimed to determine whether nephrotoxin-induced AKI disrupted renal development assessed by imaging (CFE-MRI). Methods Neonatal New Zealand rabbits received indomethacin and gentamicin (AKI) or saline (control) for four days followed by cationic ferritin (CF) at six weeks. Ex vivo images were acquired using a gradient echo pulse sequence on 7 T MRI. Glomerular number ( N glom ) and apparent glomerular volume (aV glom ) were determined. CF toxicity was assessed at two and 28 days in healthy rabbits. Results N glom was lower in the AKI group as compared to controls (74,034 vs 198,722, p < 0.01). aV glom was not different (AKI: 7.3 × 10 −4 vs control: 6.2 × 10 −4 mm 3 , p = 0.69). AKI kidneys had a band of glomeruli distributed radially in the cortex that were undetectable by MRI. Following CF injection, there was no difference in body or organ weights except for the liver, and transient changes in serum iron, platelets and white blood cell count. Conclusions Brief nephrotoxin exposure during nephrogenesis results in fewer glomeruli and glomerular maldevelopment in a unique pattern detectable by MRI. Whole kidney evaluation by CFE-MRI may provide an important tool to understand the development of CKD following AKI.

中文翻译：

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兔新生儿急性肾损伤后 MRI 检测肾单位损失


背景 急性肾损伤影响重症监护室近 30% 的早产新生儿。我们的目的是确定肾毒素诱导的 AKI 是否会破坏通过影像学 (CFE-MRI) 评估的肾脏发育。方法 新生新西兰兔接受吲哚美辛和庆大霉素 (AKI) 或生理盐水（对照）四天，然后在六周时接受阳离子铁蛋白 (CF)。使用 7 T MRI 上的梯度回波脉冲序列获取离体图像。测定肾小球数量（N glom ）和表观肾小球体积（aV glom ）。在健康兔子中评估第 2 天和第 28 天的 CF 毒性。结果 与对照组相比，AKI 组的 N glom 较低（74,034 vs 198,722，p < 0.01）。 aV glom 没有不同（AKI：7.3 × 10 -4 对比对照：6.2 × 10 -4 mm 3 ，p = 0.69）。 AKI 肾脏的皮质中呈放射状分布有一条肾小球带，而 MRI 无法检测到这些肾小球带。注射CF后，除肝脏外，身体或器官重量没有变化，血清铁、血小板和白细胞计数也有短暂变化。结论 肾发生过程中短暂接触肾毒素可减少肾小球和肾小球发育不良，其模式可通过 MRI 检测到。 CFE-MRI 的全肾评估可能为了解 AKI 后 CKD 的发展提供重要工具。