Objectives In this preclinical investigation, the feasibility of using diffusion tensor imaging (DTI) to study contrast-induced acute kidney injury (CIAKI) is explored, comparing radiographic outcomes with histopathologic and immunohistochemical findings after repeated animal exposures to iodinated contrast agent. Materials and Methods Forty-five male wistar rats were allocated to three groups (n = 15 each), each receiving two separate injections 1 day apart: group 1 (iodixanol then saline); group 2 (iodixanol twice); and control group (saline twice). Five rats were then randomly selected from each group at three separate time points (1 h, 24 h, and 120 h) for magnetic resonance imaging (MRI). Upon MRI completion, the animals were sacrificed, examining renal tissue and serum creatinine level. DTI data served to calculate fractional anisotropy (FA) and apparent diffusion coefficient (ADC). Results FA values were significantly lower in group 2 than in the others. Compared with controls, FA assessments at 1 h, 24 h, and 120 h after injections commenced were significantly lower in group 2; and ADC was significantly more pronounced at 24 h. Serum creatinine levels at 24 h were markedly elevated in both groups 1 and 2. Pearson correlation analysis revealed significant negative correlations between FA (r = −0.730; p < 0.05) or ADC (r = −0.827; p < 0.05) and tubular injury and between FA (r = −0.563; p < 0.05) or ADC (r = −0.805; p < 0.05) and hypoxia-inducible factor-1α. Conclusions Analytic approaches to DTI with better reproducibility should aid in monitoring the early pathophysiologic derangements of CIAKI, thus facilitating timely reversal of the detrimental effects.

中文翻译：

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磁共振扩散张量成像在大鼠对比剂急性肾损伤模型中的应用

目的 在这项临床前研究中，探讨了使用扩散张量成像 (DTI) 研究造影剂诱发的急性肾损伤 (CIAKI) 的可行性，并将放射学结果与动物反复暴露于碘化造影剂后的组织病理学和免疫组织化学结果进行比较。材料和方法 将 45 只雄性 wistar 大鼠分配到三组（每组 n = 15），每组接受两次单独的注射，间隔 1 天：第 1 组（碘克沙醇然后生理盐水）；第 2 组（碘克沙醇两次）；和对照组（生理盐水两次）。然后在三个不同的时间点（1 小时、24 小时和 120 小时）从每组中随机选择 5 只大鼠进行磁共振成像 (MRI)。MRI完成后，处死动物，检查肾组织和血清肌酐水平。DTI 数据用于计算分数各向异性 (FA) 和表观扩散系数 (ADC)。结果第2组的FA值显着低于其他组。与对照组相比，第 2 组在注射开始后 1 小时、24 小时和 120 小时的 FA 评估显着降低；ADC 在 24 h 时明显更明显。第 1 组和第 2 组 24 小时血清肌酐水平均显着升高。Pearson 相关分析显示 FA（r = -0.730；p < 0.05）或 ADC（r = -0.827；p < 0.05）与肾小管损伤呈显着负相关在 FA (r = -0.563; p < 0.05) 或 ADC (r = -0.805; p < 0.05) 和缺氧诱导因子-1α 之间。结论 具有更好重现性的 DTI 分析方法应有助于监测 CIAKI 的早期病理生理紊乱，