Assessment of liver function in thioacetamide-induced rat acute liver injury using an empirical mathematical model and dynamic contrast-enhanced MRI with Gd-EOB-DTPA.

PURPOSE: To evaluate thioacetamide (TAA)-induced acute liver injury in rats using an empirical mathematical model (EMM) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA). MATERIALS AND METHODS: Eighteen rats were divided into three groups (normal control [n = 6], TAA [140] [n = 6], and TAA [280] groups [n = 6]). The rats of the TAA (140) and TAA (280) groups were intravenously injected with 140 and 280 mg/kg body weight (BW) of TAA, respectively, while those of the normal control group were intravenously injected with the same volume of saline. DCE-MRI studies were performed using Gd-EOB-DTPA (0.025 mmol Gd/kg; 0.1 mL/kg BW) as the contrast agent 48 hours after TAA or saline injection. After the DCE-MRI study, blood was sampled and serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured. We calculated the rate of contrast uptake (α), the rate of contrast washout (ß), the elimination half-life of relative enhancement (RE) (T(1/2)), the maximum RE (RE(max)), and the time to (RE(max)) (T(max)) from time-signal intensity curves using EMM. RESULTS: The RE(max) values in the TAA (140) groups and TAA (280) groups were significantly smaller than that in the normal control group. The T(max) value in the TAA (280) group was significantly greater than that in the normal control group. The ß value in the TAA (280) group was significantly smaller than those in the normal control and TAA (140) groups, whereas there were no significant differences in ß among groups. The T(1/2) value in the TAA (280) group was significantly greater than those in the normal control and TAA (140) groups. The RE(max), T(max), ß, and T(1/2) values significantly correlated with AST and ALT. CONCLUSION: The EMM is useful for evaluating TAA-induced acute liver injury using DCE-MRI with Gd-EOB-DTPA.