Acute kidney injury induced by iodine contrast agent in a rabbit model using intravoxel incoherent motion and blood oxygen level-dependent imaging techniques / 中国医学影像技术

ABSTRACT

Objective: To explore the impact of non-ionic dimeric isotonic iodine contrast agent on rabbit kidneys using intravoxel incoherent motion (IVIM)-DWI and blood oxygen level-dependent (BOLD) imaging. Methods: Totally 25 male New Zealand rabbits were randomly equally divided into 5 groups (each n=5). IVIM-DWI and BOLD scanning and blood collection were performed in four experimental groups (1, 24, 48, 72 h group) 1, 24, 48,72 h after injection of iodixanol, respectively, also in base-line group after injection of equal amount of saline. The rabbits were killed immediately after MRI,and the kidneys were taken for histopathological analysis. Results: Compared with base-line group, both cortex and medulla of kidneys showed decreased ADC, D and f values and the lowest D* value, as well as increased R2* in 1 h group. The lowest ADC, D and f values, the highest R2* and increased D* value of both cortex and medulla were observed in 24 h group. In 72 h group, R2* value of both cortex and medulla were still lower than baseline (all P<0.05), and D* value basically returned to baseline, while f and D values of medulla were still statistically different with respect to baseline (all P<0.05). Meanwhile, different degrees of glomerular and tubular damage were observed in the pathological sections. The serum creatinine and blood urea nitrogen in 48 h group and 72 h group were higher than those in base-line group (all P<0.05). The expression of hypoxia inducible factor-1α and heme oxygenase-1 increased in 1 h group and up to peak in 24 h group. Conclusion: Combining IVIM-DWI with BOLD can effectively evaluate rabbit renal pathophysiologic changes associated with contrast-induced acute kidney injury.