基于X线相衬成像的CCl_4诱导肝纤维化微观结构成像研究

Microstructure imaging of liver fibrosis induced by CCL_4 based on X-ray phase contrast imaging

目的探讨分析X线相衬成像(phase contrast imaging, PCI)技术在观察CCl_4肝纤维化模型病理学改变及微血管变化的应用价值。方法样本包括18只SD大鼠肝脏,按纤维化等级分为正常组、中度肝纤维化组和重度肝纤维化组,每组各6只;利用PCI技术对样品进行成像,同时对成像后的样品进行病理学检查。结果病理切片显示随着纤维化程度加重,胶原纤维面积比逐渐增大,3组间比较差异有统计学意义(P<0.01);PCI图像清晰地显示了肝脏微血管分布,微血管密度变化与病理切片结果一致,3组间微血管密度差异有统计学意义(P<0.01);随着纤维化程度的加重,血管分支增多,血管直径减小,同级血管直径3组间比较差异有统计学意义(P<0.01);肝脏表面纹理随纤维化的加重,逐渐变得凹凸不平或呈波浪状,纹理分析差异有统计学意义(P<0.05)。结论 PCI技术可清晰地显示大鼠纤维化肝脏微血管、表面纹理等微观结构变化,并进行相关指标的定量分析,为肝脏疾病的临床辅助诊断提供参考。

Objective To investigate the value of X-ray phase contrast imaging(PCI) in observing pathological and microvascular changes of liver fibrosis model induced by carbon tetrachloride(CCl4) in rats. Methods Eighteen Sprague-Dawley(SD) rats were divided into the normal group, moderate group and severe group based on different fibrosis grades. The livers of rats were imaged via X-ray PCI technology and examined for pathological changes after imaging.Results The pathological examination showed that the proportion of fibrosis area was gradually increased with the development of liver fibrosis, and there were significant differences among the three groups(P<0.01). Moreover, the projection images clearly showed the microvascular distribution in livers. The changes of microvessel density were consistent with pathological results, and significant differences were detected among the three groups(P<0.01). The vascular branches were increased with fibrosis progression. Conversely, vascular diameters decreased, and there was significant difference among the three groups(P<0.01). Additionally, surface texture of livers gradually became jagged or wavy, and texture analysis has significant difference(P<0.05). Conclusion X-ray PCI can clearly reveal the microstructural changes of the microvessel and surface texture of livers. Quantitative analysis of relevant indicators can also be performed, which provides some reference value for the clinical diagnosis and treatment of liver diseases.