慢性肾病(CKD)的特征在于肾脏中的炎症和纤维化。肾活检和估计的肾小球滤过率(eGFR)仍然是护理标准,但是这些端点在检测阶段方面有局限性,programming,和肾脏纤维化病理的空间分布。MRI扩散张量成像(DTI)已成为一种有前途的非侵入性技术,可在临床和临床前研究中评估体内肾脏纤维化。然而,这些影像学研究尚未系统地确定纤维化,特别是在肾中,活检取样有限,或者完成了对整个器官组织学的广泛分析,血液生物标志物,和基因表达来评估MRI评估肾纤维化的相对优势和劣势。在这项研究中,我们在CKD的草酸钠小鼠模型中进行了DTI。DTI参数分数各向异性,表观扩散系数,通过感兴趣区域(ROI)分析比较对照组和草酸盐组之间的轴向扩散率,以确定皮质和髓质的变化。此外,实施基于体素的分析(VBA)以系统地识别整个肾脏的局部损伤区域.通过ROI分析和VBA,发现DTI参数在延髓中存在显着差异,其在空间上也与胶原蛋白IIIIHC匹配。该髓质区域的DTI参数与组织学表现出中等到强的相关性,血液生物标志物,羟脯氨酸和基因表达。因此,我们的结果强调了DTI对肾脏纤维化异质性的敏感性以及全肾脏非侵入性成像的重要性。
Chronic kidney disease (CKD) is characterized by inflammation and fibrosis in the kidney. Renal biopsies and estimated glomerular filtration rate (eGFR) remain the standard of care, but these endpoints have limitations in detecting the stage, progression, and spatial distribution of fibrotic pathology in the kidney. MRI diffusion tensor imaging (DTI) has emerged as a promising noninvasive technology to evaluate renal fibrosis in vivo both in clinical and preclinical studies. However, these imaging studies have not systematically identified fibrosis particularly deeper in the kidney where biopsy sampling is limited, or completed an extensive analysis of whole organ histology, blood biomarkers, and gene expression to evaluate the relative strengths and weaknesses of MRI for evaluating renal fibrosis. In this study, we performed DTI in the sodium oxalate mouse model of CKD. The DTI parameters fractional anisotropy, apparent diffusion coefficient, and axial diffusivity were compared between the control and oxalate groups with region of interest (ROI) analysis to determine changes in the cortex and medulla. In addition, voxel-based analysis (VBA) was implemented to systematically identify local regions of injury over the whole kidney. DTI parameters were found to be significantly different in the medulla by both ROI analysis and VBA, which also spatially matched with collagen III immunohistochemistry (IHC). The DTI parameters in this medullary region exhibited moderate to strong correlations with histology, blood biomarkers, hydroxyproline, and gene expression. Our results thus highlight the sensitivity of DTI to the heterogeneity of renal fibrosis and importance of whole kidney noninvasive imaging.NEW & NOTEWORTHY Chronic kidney disease (CKD) can be characterized by inflammation and fibrosis of the kidney. Although standard of care methods have been limited in scope, safety, and spatial distribution, MRI diffusion tensor imaging (DTI) has emerged as a promising noninvasive technology to evaluate renal fibrosis in vivo. In this study, we performed DTI in an oxalate mouse model of CKD to systematically identify local kidney injury. DTI parameters strongly correlated with histology, blood biomarkers, hydroxyproline, and gene expression.