Blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) and diffusion tensor imaging (DTI) are useful methods for investigating the morphology and function of the kidneys, including revealing unilateral renal damage. Nevertheless, these techniques have not yet been applied for bilateral renal function. The aim of this study was to investigate whether the combination of DTI and BOLD could be used to examine different degrees of contrast-induced acute kidney injury (CI-AKI) in bilateral kidneys compared to standard methods such as serum creatinine (SCr) detection. Forty-Two New Zealand white rabbits were divided into two groups: the experimental group and the control group. Physiological saline and iodine contrast agent (iohexol, 1.0 g iodine/kg, 1.0 ml/sec) were injected via the right renal artery. DTI and BOLD-MR data were acquired longitudinally at the baseline and 1, 24, 48, and 72 h after high-pressure syringe injection to measure the apparent diffusion coefficient (ADC), fractional anisotropy (FA) and relative transverse relaxation rate (R2*). After the MR scan at each time point, three rabbits in each group were sacrificed, and changes in SCr and hypoxia-inducible factor-1α (HIF-1α) were analyzed using histopathology and immunochemistry. Twenty-four hours after iohexol administration, the values of ADC and FA decreased significantly (P < 0.05), while R2* values increased (P < 0.05) in the renal cortex (CO), outer medulla (OM) and inner medulla (IM). Besides, significant negative correlations were observed among ADC, FA, and R2* in CO, OM, and IM (all P < 0.001, r = − 0.654–0.828). DTI and BOLD can simultaneously and non-invasively assess different degrees of CI-AKI in bilateral kidneys.

中文翻译：

---

应用弥散张量成像和血氧水平依赖性磁共振成像评估碘海醇诱导兔双侧肾功能。

血氧水平依赖性磁共振成像 (BOLD-MRI) 和弥散张量成像 (DTI) 是研究肾脏形态和功能的有用方法，包括揭示单侧肾损伤。然而，这些技术尚未应用于双侧肾功能。本研究的目的是探讨与血清肌酐 (SCr) 检测等标准方法相比，DTI 和 BOLD 的组合是否可用于检查双侧肾脏不同程度的造影剂诱导的急性肾损伤 (CI-AKI)。42只新西兰白兔分为两组：实验组和对照组。通过右肾动脉注射生理盐水和碘造影剂（碘海醇，1.0 g碘/kg，1.0 ml/sec）。在基线和高压注射器注射后 1、24、48 和 72 小时纵向采集 DTI 和 BOLD-MR 数据，以测量表观扩散系数 (ADC)、分数各向异性 (FA) 和相对横向弛豫率 (R2 *）。在每个时间点进行MR扫描后，每组处死3只兔子，使用组织病理学和免疫化学分析SCr和缺氧诱导因子1α（HIF-1α）的变化。碘海醇给药后 24 小时，ADC 和 FA 值显着下降（P < 0.05），而肾皮质（CO）、外髓质（OM）和内髓质（IM）的 R2* 值升高（P < 0.05） ）。此外，在 CO、OM 和 IM 中，ADC、FA 和 R2* 之间存在显着的负相关（所有 P < 0.001，r = - 0.654–0.828）。