Zhao Yi-Ping, Guo Dong-Mei, Liu Hui, Liu Wen-Hong, Mu Wen-Ying, Zhang Peng
Department of Radiology, Second Affiliated Hospital, Dalian Medical University Dalian 116027, China.
Department of Biomedical Engineering, Dalian University of Technology Dalian 116024, China.
Int J Clin Exp Med. 2015 Feb 15;8(2):2197-204. eCollection 2015.
To evaluate the utility of ADC values and Gd-DTPA equilibrium phase MR imaging in staging hepatic fibrosis in rats. 48 rats were allocated into experimental and control groups. Experimental rats were subcutaneously injected with a mixture of CCl4. From 4th-12th weeks, MR images were obtained, which include pre-enhanced phase imaging, DWI and equilibrium phase imaging. Then the rat groups were subdivided according to the stages of fibrosis (S0, S1, S2, S3 and S4) after histopathological analysis. The original MRI data were forwarded to the workstation to obtain apparent diffusion coefficient (ADC) maps at b value of 500 s/mm(2). Pre-enhanced phase and equilibrium phase signal intensities and relative contrast enhancement index (RCEI) were measured as well. Lastly, the ADC values and RCEI of the experimental group were compared with each other and with the control group. All statistical analyses were carried out with SPSS, where P < 0.05 is considered to represent a significant difference. Hepatic ADC values are significantly different between the experimental and control groups (P = 0). There is a statistically significant difference between the experimental and control groups on RCEI (P = 0). Comparing the S1, S2, S3 and S4 groups, there is a statistically significant difference between the mild group (S1 and S2) and the severe group (S4) in terms of ADC values and RCEI (all P < 0.05). A statistically significant difference is also found between the moderate group (S3) and the severe group in ADC values. As the degree of fibrosis increases, there are a reduction in ADC values and an increase in RCEI. Comparing the groups with ADC values and enhancement index, there are statistically significant differences in sensitivity and specificity on diagnosis of hepatic fibrosis. The ADC values have the best sensitivity (93.1%) and specificity (83.3%). Quantitative ADC values and RCEI may be helpful to the staging of rat fibrosis, but their application in human is controversial.
评估表观扩散系数（ADC）值和钆喷酸葡胺（Gd-DTPA）平衡期磁共振成像（MRI）在大鼠肝纤维化分期中的应用价值。将48只大鼠分为实验组和对照组。对实验组大鼠皮下注射四氯化碳（CCl4）混合物。在第4至12周期间，获取磁共振图像，包括预增强期成像、扩散加权成像（DWI）和平衡期成像。然后在组织病理学分析后，根据纤维化分期（S0、S1、S2、S3和S4）对大鼠组进行细分。将原始MRI数据传输至工作站，以获得b值为500 s/mm²时的表观扩散系数（ADC）图。同时测量预增强期和平衡期信号强度以及相对对比增强指数（RCEI）。最后，将实验组的ADC值和RCEI相互比较，并与对照组进行比较。所有统计分析均使用SPSS软件进行，P < 0.05被认为具有显著差异。实验组和对照组之间的肝脏ADC值存在显著差异（P = 0）。实验组和对照组在RCEI上也存在统计学显著差异（P = 0）。比较S1、S2、S3和S4组，轻度组（S1和S2）与重度组（S4）在ADC值和RCEI方面存在统计学显著差异（所有P < 0.05）。在ADC值方面，中度组（S3）与重度组之间也存在统计学显著差异。随着纤维化程度的增加，ADC值降低，RCEI升高。比较具有ADC值和增强指数的各组，在肝纤维化诊断的敏感性和特异性方面存在统计学显著差异。ADC值具有最佳的敏感性（93.1%）和特异性（83.3%）。定量ADC值和RCEI可能有助于大鼠纤维化的分期，但其在人体中的应用存在争议。
