Mapping kidney tubule diameter ex vivo by diffusion MRI.
Mapping kidney tubule diameter ex vivo by diffusion MRI.
复制标题
通过扩散 MRI 绘制离体肾小管直径。
DOI：
10.1152/ajprenal.00369.2020
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Bennett,KevinM
中科院分区：
文献类型：
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作者：
Morozov,Darya;Parvin,Neda;Charlton,JenniferR;Bennett,KevinM
肾小管病变是肾脏疾病的共同特征。目前评估肾脏健康的指标，无论是体内还是移植，通常是基于尿液或血清生物标志物以及肾活检的病理结果。活组织检查通常取自肾皮质，是侵入性的，而且容易出现抽样错误。直接和无创测量肾小管病理的工具可以提供一种评估肾脏健康的新方法。本研究使用扩散磁共振成像（dMRI）作为一种无创工具来测量离体灌注肾脏的管腔大小。我们首先使用蒙特卡罗模拟来证明dMRI对肾小管尺度上受限制的组织水扩散敏感。我们应用dMRI和生物物理模型来检测小鼠、大鼠和人类供体离体固定肾脏的肾管直径分布。拟合dMRI信号的生物物理模型是基于不同直径的无限长圆柱体内自由扩散的水和扩散的水的叠加。dMRI测量的管径与组织学在同一组织内测量的管径相差在10%以内。最后，我们应用dMRI研究了叶酸致急性肾损伤小鼠模型的肾脏病理。dMRI检测到急性肾损伤小鼠肾皮质内小管分布与对照组相比存在异质性。我们的结论是，dMRI可以用于测量肾皮质离体小管直径的分布，并且dMRI可能提供一种新的无创小管病理生物标志物。肾小管病变是肾脏疾病的共同特征。目前评估肾脏健康的指标，无论是体内还是移植，通常是基于尿液或血清生物标志物以及肾活检的病理结果。弥散MRI可用于体外测量肾皮质小管直径的分布，可能为小管病理提供一种新的无创生物标志物。
Tubular pathologies are a common feature of kidney disease. Current metrics to assess kidney health, in vivo or in transplant, are generally based on urinary or serum biomarkers and pathological findings from kidney biopsies. Biopsies, usually taken from the kidney cortex, are invasive and prone to sampling error. Tools to directly and noninvasively measure tubular pathology could provide a new approach to assess kidney health. This study used diffusion magnetic resonance imaging (dMRI) as a noninvasive tool to measure the size of the tubular lumen in ex vivo, perfused kidneys. We first used Monte Carlo simulations to demonstrate that dMRI is sensitive to restricted tissue water diffusion at the scale of the kidney tubule. We applied dMRI and biophysical modeling to examine the distribution of tubular diameters in ex vivo, fixed kidneys from mice, rats, and a human donor. The biophysical model to fit the dMRI signal was based on a superposition of freely diffusing water and water diffusing inside infinitely long cylinders of different diameters. Tubular diameters measured by dMRI were within 10% of those measured by histology within the same tissue. Finally, we applied dMRI to investigate kidney pathology in a mouse model of folic-acid-induced acute kidney injury. dMRI detected heterogeneity in the distribution of tubules within the kidney cortex of mice with acute kidney injury compared with control mice. We conclude that dMRI can be used to measure the distribution of tubule diameters in the kidney cortex ex vivo and that dMRI may provide a new noninvasive biomarker of tubular pathology.NEW & NOTEWORTHYTubular pathologies are a common feature of kidney disease. Current metrics to assess kidney health, in vivo or in transplant, are generally based on urinary or serum biomarkers and pathological findings from kidney biopsies. Diffusion MRI can be used to measure the distribution of tubule diameters in the kidney cortex ex vivo and may provide a new noninvasive biomarker of tubular pathology.