Evaluation of Kidney Injury Using Arterial Spin Labeling and Blood Oxygen Level‐Dependent MRI: An Experimental Study in Rats With Carbon Tetrachloride‐Induced Liver Cirrhosis

Abstract

BackgroundSerum creatinine (Scr) may be not suited to timely and accurately reflect kidney injury related to chronic liver disease. Currently, the ability of arterial spin labeling (ASL) and blood oxygen level‐dependent (BOLD) sequences to evaluate renal blood flow (RBF) and blood oxygen in chronic liver disease remains to be verified.PurposeTo investigate the value of ASL and BOLD imaging in evaluating hemodynamics and oxygenation changes during kidney injury in an animal model of chronic liver disease.Study TypeProspective.Animal ModelChronic liver disease model was established by subcutaneous injection of carbon tetrachloride. Forty‐three male Sprague–Dawley rats (8 weeks) were divided into a pathological group (0, 2, 4, 6, 8, 12 weeks, each group: N = 6) and a continuous‐scanning group (N = 7).Field Strength/Sequence3‐T, ASL, BOLD, and T2W.AssessmentRegions of interest in the cortex (CO), outer stripe of the outer medulla (OSOM), and inner stripe of the outer medulla (ISOM) are manually delineated. The RBF and T2* values at each time point (0, 2, 4, 6, 8, 12 weeks) are measured and compared. Hematoxylin–eosin score (HE Score, damage area scoring method), alpha‐smooth muscle actin (α‐SMA), hypoxia‐inducible factor‐1alpha (HIF‐1α), peritubular capillar (PTC) density, Scr, and neutrophil gelatinase‐associated lipocalin were harvested.Statistical TestsAnalysis of variance, Spearman correlation analysis, Kruskal–Wallis tests, and receiver operating characteristic analysis with the area under the curve (AUC). A P‐value <0.05 was considered statistically significant.ResultsRenal RBF and T2* values of CO, OSOM, and ISOM were significantly different from baseline. Both RBF and T2* were significantly correlated with HE Score, α‐SMA, HIF‐1α, and PTC density (|r| = 0.406–0.853). RBF demonstrated superior diagnostic capability in identifying severe kidney injury in this model of chronic liver disease (AUC = 0.964).Data ConclusionImaging by ASL and BOLD may detect renal hemodynamics and oxygenation changes related to chronic liver disease early.Evidence Level5Technical EfficacyStage 2